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Gold Member Username: KeggerMICHIGAN Post Number: 2120 Registered: Dec-03 | Hey Jan while your here or later! lol Any thoughts on the 6DJ8/6922 used as a preamp tube? The reason I ask is I just got what I believe to be a good deal on the anthem pre 2L. (which uses (4) 6DJ8/6922 in it's preamp section) One of the selling features for me on this unit is the ssp passthrough! Also it has remote control which for me is almost a must! The link below does a descent job of technical and observation of the unit. http://www.audio-ideas.com/reviews/preamps/anthem-pre2l.html |
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J. Vigne Unregistered guest | The 6DJ8 has been a popular tube in pre amps for a few decades. My main pre amp, the Audible Illusions Modulus 3, uses 6DJ8's exclusively. I've never looked into the all the reasons why this tube was chosen by several manufacturers over the 12AX7. If I remember correctly VTL, Manley and, New York Audio Labs (the old Gizmo factory) along with Audible Illusions were the most ardent supporters of this tube for use in a pre amp. (VTL and Manley also regarded the 6L6 as a forgotten marvel of output tubes in consumer audio; feeling it had been relegated to the fuuz/wah of guitar amps.) The 6DJ8 had not been designed to be strictly used in audio from what I was told. It was typically found in the audio section of a video receiver from everything I've seen on the tube. Apparently it was first used in the early '80's to get more gain from a phono circuit in the days when the Koetsu's and their like were becoming popular among the moving coil cartridge fans. The miniscule voltages of the MC cartridges of that time pushed the noise level of circuits using more conventional tubes; and, the 6DJ8, with higher gain than a 12AX7, was the choice for gain and sound quality. Almost every pre amp I can remember that used the 6DJ8 got good if not outstanding reviews and many have become cult favorites over the years. Of course it takes more than just a choice of tube to make a product perform. There are still people who insist the 12AX7 is the only real tube for pre amps and I have read of a few modifiers who will rewire the Audible Illusions to accept the 12AX7 when the additional gain isn't needed. My personal impressions of the tube are that it's much harder to find great sounding 6DJ8's than it is 12AX7's, but, that's true of almost any tube. The 12AX7 is just so popular the manufacturers are going to put their resources into what will sell. I have a selection of 6DJ8's that I bought over ten years ago that I will rely on until I run out. They are mostly Seimens and I was told these were manufactured, I believe, in Denmark. The very best sounding tube of the lot is pretty microphonic so its use requires some special set up with the pre amp in a different room than the speakers. It doesn't show its weaknesses so much with the LS3/5a's since they have litle deep bass, but, even the Spicas were able to get things ringing if I got the volume and record wrong. But I've not heard a 12AX7 that sounds as good as these particular tubes. So, if you search and try a few tubes you can get sound that is easily as good as the 12AX7. Overall I'd compare the 6DJ8 to the 12AX7 as the E88CC having slightly better, firmer bass response; slightly less sweet mids (which can be a good thing in some systems); a huge soundstage that is deep and wide with excellent placement that most 12AX7's can't quite match; depending on the tube, detail as good as the best 12AX7 I've owned; highs that are clean and well separated from each other with no smear; and, most importantly, very quite backgrounds. A 12AX7, on the other hand is the clasic pre amp tube and most of the memorable pre amps I've heard all use this tube. The Mac tube pre amps, the Marantz 7C and the Conrad Johnson PV-5 all had 12 AX7's; and, they are all pre amps you could listen to forever if you weren't obsessed with the sound being the most accurate but instead being the most musical. This is a combination where, in my system, the 6DJ8 was a good choice to keep the 12AX7's and similar tubes in the Mac MC240's from being over the top as far as "tube sound". Whenever I had one of the 12AX7 based pre amps in the system I was in love with the sound but it could easily be too much of a good thing (particularly when the Macs had the RAM tubes) and I needed to dry it out just a bit for everday listening. The 6DJ8 did that for me and gave me the benefits of the soundstage and the lower noise floor. When the Macs had the Sovtek 5881's, the 12AX7 in the pre amp might have been a good choice to go the other way. |
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Gold Member Username: KeggerMICHIGAN Post Number: 2121 Registered: Dec-03 | Great info Jan. Yah as I've been reading on this tube it is starting to get a good list of followers and as you mentioned just like the 5881 output tube was not designed with what we are using it for in mind but many have said it's use started out in Oscilloscope's and oscillator's. It is a little more expensive then 12ax7's and a little more scarce but I've been doing some hard digging and find more sustitutes for this tube then any other I've come accross yet! 6922 e88cc 6DJ8 CV2493 E88CC-01 7308 E188CC ECC88 6H23pi 6N23P-EV CV2492 CCA 6922WA CV10320 CV8065 ECC868 CV5358 As you mentioned I have heard the talk of some of these tubes being noisier then others and suposably the 7308 is the cream of the crop in this stable. The following are suppose to be "near" sustitutes that should work. 21DJ8, 7DJ8, CV10403, PCC88, UCC88 The preamp should be here by about thursday of next week and I've won a few ebay auctions on tubes "at the price I'm willing to pay" so we will get some good testing done and hopefully a little tube rolling "fun"! |
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Silver Member Username: Rick_bNew York USA Post Number: 766 Registered: Dec-03 | Hi All, As I wait for my Jolida to arrive, I have been doing a little research on tubes in antipicipation of tube rolling. The amp comes with Sovtek EL84 tubes. This was a pleasant surprise, I thought it would come with Chinese tubes. I am told the Sovtek's are a good tube, so I will have a good starting point. As I started looking at various tubes recommended, such as Electro-Harmonix by Bill Baker at Response Audio, I stumbled accross something that stopped me in my tracks. The Genelex Gold Lion at $499.95 per tube. OK, Rick, deep easy breaths, easy now. So now the question is: Have I found the Holy Grail of tubes? Is any one crazy enough to put $2000 worth of tubes into a $600 amp? Is this your final revenge Mr. Vigne? To send me on a never ending quest for the perfect, unobtainable EL84? A perfect sinister plan Mr. Vigne. My compliments, sir. A plot worthy of Moriarty and Holmes. Will I wind up like Gollum, consumed by the one tube that rules them all? Please tell me of my fate. |
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Gold Member Username: KeggerMICHIGAN Post Number: 2142 Registered: Dec-03 | Rick the problem with some of the so called better tubes is a lot of the names of the companies have been bought up by new sensor corp in turn are marketing new tubes under the old names! some of them are sovtek and svetlana so you have to be careful if your getting nos. Also jj/tesla has been using the old tesla name to premote new tubes. These new tubes do not compare to the old ones in my experience and everything I read! Probably the best of the new companies is electro harmonex and ei. Otherwise I'm stocking up on nos tubes I get from ebay. Those genelex are suppose to be the cream of the crop. But from what I've found telefunken and mullard are just as highly regarded without the completly rediculuos price tag! Then you have nos american companies that had excelent quality and are suppose to compete with the likes of telunken and mullard. So first I look for mullard and telefunken followed by nos us tubes. The mullard name has also been purchased latley then there's telefunken copies out there so be carful there too. But so far I've been really happy with what I've gotten on ebay without any issues! The nos us tubes I first generally look for are sylvania followed by ge and rca. Im sure jan has some solid input here also. But I truly suggest throwing some bids on ebay and see what you hook. That's what I do and I've got nice quality tubes coming out my bottom end for great prices! |
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J. Vigne Unregistered guest | An evil laugh comes out of the Texas plains and sweeps across the frozen tundra of the North. What Kegger has told is pretty much the story on NOS tubes. I can vouch for the quality of the original Gold Lions. I borrowed a pair of KT66's for a weekend to use in my Macs and I have never had a better sounding tube in my system. Along with the Mullard, Sylvania and RCA tubes, the Gold Lion products were the best of the best for power tubes. I came very close to the sound of the G.L. tubes when I used the Golden Dragon KT66's out of China. The story on those tubes was a group of former Genelex employees bought the rights to the design using backer money out of the US and England. The tubes were made on some of the original equipment that had ended up in China. The Golden Dragon tubes as a complete set from rectifier to output tubes were the second best tube I've heard in my amplifiers. However, they were rather unreliable and needed replacement in a short while. The same tube is supposedly now being made by Shuguang with "improvements" to reliability according to the salesperson I spoke with. At $500 a tube the Genelex become the equivalent of the rare bottle of wine from 1963. The price prohibits the use of the product. Tubes will eventually wear out and then the tube is worth $0. These NOS tubes are mostly the province of collectors who, as with wine, prefer to say they own the tube rather than listen to the tube. And so they are unlikely to be used in a $600 amp or most an amp for that matter. As Kegger points out there are many scams in NOS tubes and until you get to the point where you are confident in spending the money knowing you are getting what is advertised, obviously you buy at your own risk. Use the Sovteks and get used to the amp so you have some idea where you want to take the amp when you get new tubes. Reading the web sites will be your best guide. Some of the tube forums are helpful but are also full of personal opinion that relates to their system alone. And one thing about tubes is they will wear out. So even if you don't care as much for a tube after you buy it, you will have a reason to replace it. Those old tubes become great items for use while you're checking the amp for noises or doing upgrades. Power the amp up with the other tubes and if there is a problem it will blow out your bad tubes instead of the ones you just paid $500 @ to obtain. Along those lines, I would order at least one new tube to match whatever you intend to use for any length of time. Use this as a spare in case the amp or the tubes have problems. It might save you buying a whole new tube set. |
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J. Vigne Unregistered guest | 6DJ8 tubes: http://www.audibleillusions.com/technical/bulletin5.htm |
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Silver Member Username: Rick_bNew York USA Post Number: 784 Registered: Dec-03 | As I wait for the arrival of the Jolida, can someone give me a step by step crash course on how to bias my amp? Thanks in advance. |
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Gold Member Username: KeggerMICHIGAN Post Number: 2168 Registered: Dec-03 | yo rick email me and i can call you from work. (leave a number to reach you) I got time right now or later today! thykegman@comcast.net |
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Gold Member Username: KeggerMICHIGAN Post Number: 2169 Registered: Dec-03 | Here would be my version if I wrote it down. (kinda) First find out what the bias voltage should be from manufacturer or manual. (all amps are different depending on curcuit/resisters used) set your meter appropriatly. Turn bias pots all the way down then back about 1.5 turns (manufacturer or manual for correct direction and or pot turns) connect your meter in the appropriate test positions. Fire it up with speakers and something on the input. watch the voltage rise if safely under as it starts to stablize check others rather quickly. If it dos not start to stablize at a reasonable voltage and or tubes glow excessivly red hot turn off and call manufacturer. If all are safely under then begin to adjust individually close to the magic number then keep going back over all tubes until they are all in spec. When adjusting some tubes may change others so you will have to go over them all quite a few times. (not allways) well that's about the best I got. |
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J. Vigne Unregistered guest | I think you'll find the method you want to follow laid out in your owner's manual. Kegger's method is a good general description of how to accomplish the task. I would only add what the technicians I worked with included in the procedure. Turn out the lights. When you are going to first fire up the amplifier, it is easy to see any tube that is different from the rest when the lights are off. If a tube glows red or doesn't come to the right temperature, you will see this plainly in a darkened room. Then you need to take action by either adjusting the bias or shutting down the amp. Once you are sure the tubes are coming up to temperature evenly, you can turn on the lights so you can see to adjust the bias. |
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Silver Member Username: Rick_bNew York USA Post Number: 785 Registered: Dec-03 | Thanks Kegger. The more I think about it, I'll e-mail you when I get the amp, and you can walk me through the process. I'm getting a little anxious, I want to play. LOL! |
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Silver Member Username: Rick_bNew York USA Post Number: 786 Registered: Dec-03 | Sorry Jan, we crossed posts and didn't see yours. I appreciate the tip. I'll send up a flare if I run into trouble. |
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Silver Member Username: Rick_bNew York USA Post Number: 789 Registered: Dec-03 | IT'S HERE! I had it drop shipped to my work address. Now I must endure the torture of looking at the box, on the floor of my office. Don't you hate it when work gets in the way of your hobby? |
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J. Vigne Unregistered guest | That's why you make your hobby your work. |
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Silver Member Username: Rick_bNew York USA Post Number: 790 Registered: Dec-03 | Jan, you are so right. If only I could just get it to pay the bills. LOL! |
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J. Vigne Unregistered guest | That I understand. |
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Gold Member Username: KeggerMICHIGAN Post Number: 2174 Registered: Dec-03 | I have most of my stuff shipped to work also and it does suck to lok at it all day! Hope it's worth the wait rick and it's all good! |
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Silver Member Username: Rick_bNew York USA Post Number: 793 Registered: Dec-03 | Thanks Kegman! I got as far as unpacking and installing the tubes. I was very surprised to see that the amp was shipped with Electro-Harmonix tubes. I was the told that Sovtek's were standard. I will set up and give a listen tonight. |
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Gold Member Username: MyrantzPost Number: 1359 Registered: Aug-04 | Rick WELL? |
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Silver Member Username: Rick_bNew York USA Post Number: 798 Registered: Dec-03 | OK Already-LOL! Can't a guy listen for awhile? A full review of the amp and my personal opinion will follow in due time. Tubes take time to "bloom", and that has not happened in the approximate 10-12 hours of listening. A few first impressions. Right out of the box it sounded very much like the Mac 6100. (not a bad thing) I can't believe that a 20wpc amp can drive a 84dB speaker as easily as it does. It drives the speaker to well above normal listening levels. I listened to the S3/5's at the 12 O'Clock position on the volumn control. Talk about headroom. It provides a wider sound stage of any other amp I have owned. Great imaging and resolution of inner detail. Attacks and decays of which I have never experienced before. Much more air around everything. Sorry Ben, nothing I have ever heard does strings or vocals better than the S3/5. Especially now. I was told that tubes have a way of pulling you in, closer to the music. I already have a sense of that. My biggest fear is that I am going to be sitting there when the tubes open up, and it will be like getting sucked into a harmonic black hole I'll never want to escape from. Tubes Good |
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J. Vigne Unregistered guest | In case anyone missed it on another thread (I just like saying it so much), " ... tubes are all about how the note starts and stops and all the moments in between those two points." It's something totally different from transistors, eh, Rick? |
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Silver Member Username: Rick_bNew York USA Post Number: 799 Registered: Dec-03 | TUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUBES Good! |
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Gold Member Username: MyrantzPost Number: 1362 Registered: Aug-04 | Rick LOL and Holy Cow! I see a Hollywood script emerging here: "The Day The Tubes Opened Up" :-) Will await your review once you discover what effect that harmonic black hole has on your brain! |
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Gold Member Username: MyrantzPost Number: 1363 Registered: Aug-04 | Jan, read the following out loud" " ... tubes are all about how the note starts and stops and all the moments in between those two points." Hope you enjoyed that :-) |
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Gold Member Username: John_aPost Number: 2780 Registered: Dec-03 | " ... tubes are all about how the note starts and stops and all the moments in between those two points." Hmmm... Personally, I am also interesting in before, and after. Nice post, Rick. More, please! |
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Gold Member Username: John_aPost Number: 2781 Registered: Dec-03 | I see a Hollywood script emerging here: "The Day The Tubes Opened Up" Something like: "We are come to warn you that other civilizations found they were unable to control multi-channel sound, and, in consequence, perished". |
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Gold Member Username: MyrantzPost Number: 1365 Registered: Aug-04 | John A What treachery you utter Sir! I'd rather perish in surround utopia than be led like a sheep into some black hole where one may live in fear for all eternity unable to escape what's between the starting and stopping of a note. |
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Silver Member Username: Rick_bNew York USA Post Number: 800 Registered: Dec-03 | "It's something totally different from transistors, eh, Rick?" ............YEP............... " Hmmm....Personally, I am also interested in before, and after." I think the before would be the decay, and perhaps silence, until the attack of the next note. The next note(s) being the after. "The Day The Tubes Opened Up" I think the experience will be like a Buddhist reaching total consciousness. |
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J. Vigne Unregistered guest | Start, good, good, good, good, good, good, good, good, good,good, good, good, good, good, good, good, good, stop, good, good, good, good, good, good, good, good, good,good, good, good, good, good, good, good, good, start, good, good, good, good, good, good, good, good, good,good, good, good, good, good, good, good, good, stop, good, good, good, good, good, good, good, good, good,good, good, good, good, good, good, good, good, start, good, good, good, good, good, good, good, good, good,good, good, good, good, good, good, good, good, stop, good, good, good, good, good, good, good, good, good,good, good, good, good, good, good, good, good, start, good, good, good, good, good, good, good, good, good,good, good, good, good, good, good, good, good, stop, good, good, good, good, good, good, good, good, good,good, good, good, good, good, good, good, good, start, repeat ... |
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J. Vigne Unregistered guest | If you're interested in before and after all that, John, you'll have to take the amp out for drinks before and share a cigarette after. |
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Silver Member Username: Rick_bNew York USA Post Number: 801 Registered: Dec-03 | ........YEP........ am I on the right path here, Jan? |
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Gold Member Username: KeggerMICHIGAN Post Number: 2181 Registered: Dec-03 | So ricky you lika da tubes aye? Good to hear my man! Good to hear! I'm allways tweaking and listening to my different amps. Most of my Mods are finally starting to settle and break in. I'm finding what I enjoy most is the rich harmonics I'm getting. That to me is what I mean by instruements sounding real! The difference between a recorded guitar being played and one being played right there in the same room as you! Those lucsious harmonics give it depth! |
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Silver Member Username: Rick_bNew York USA Post Number: 802 Registered: Dec-03 | Know I know what you mean my friend. You really have to hear it for yourself. Rich, liquid, harmonics. How was your Super Bowl Party? LOL! I may have to make one of those one year. Cheers! |
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Gold Member Username: John_aPost Number: 2782 Registered: Dec-03 | If you're interested in before and after all that, John, you'll have to take the amp out for drinks before and share a cigarette after. Jan, paraphrasing old jokes seems to suit Old Dogs. That's the four best things in life, then... [My UK brain cannot filter out further associations of "tubes". Not all pleasant. I suppose this madness could be prevented from speading, if people get their tubes tied. Or snipped. Hope you do not mind "valves". What are they called in Aus, MR?] Now, you guys all clearly have minds of your own, and we are not at all in lemming country. Yet there is consensus, which I think may be discerned in the last few posts, especially. And the balanced and careful evaluations from such as Rick and Jan. See the summary on Monday, February 07, 2005 - 11:42 am for example. No one has said anything "rocks" yet. I cannot audition a valve amp, even here. The PrimaLuna review in March HF News recommends taking your speakers along for the demonstration, but that is not practical, and I know it would take me days, if not weeks, to get used to the room. So I would tend go direct sale, money back within 30 days if not delighted etc. So I was thinking, pardon the newbie question, I am new to all this; will I get better sound from changing to a valve amp (with 1980 KEF Corellis on flower pot stands), or from getting, say, a used pair of Quad ESL 63s speakers for about the same price? My present system is all over the place. For the first time for many years I can afford a little upgrade and self-indulgence. Say 1 k£. Both options have negative WAF, but the WAF and HAF are closely linked, so, if it is really good, we will both end up in credit. (This is how it should be, imho). Or should I swallow my pride and go SACD? My Rantz has nearly convinced me to give it a go. [Will respond on other thread, MR; thanks; have read; little time]. Short-list of "affordable" valve amps in UK (see Dec 14 for links): PrimaLuna Prologue One PrimaLuna Prologue Two Icon Audio Affordable Valve Company Any Others? I do not think I am currently set up for kits, having little time or space. And all my tools etc are in another country with the wrong plugs on. Alternatively, speakers: Quad ESL 63; Quad ESL 57; Quad ESL 988 (this last too expensive, really). Oh, by the way, and before I forget: I urgently need to know - how long is a piece of string? I need to know by yesterday. Better, last week. I saw one on eBay. A frayed knot. Thanx fellas. Etc. |
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Silver Member Username: Rick_bNew York USA Post Number: 803 Registered: Dec-03 | Hi John, I just read a review in Stereophile on the PrimaLuna Prologue One. Although the review was generally favorable, there were a couple of issues that would make me rethink the unit. I can't remember off the top of my head. I will reread the review and get back to you. As far as "affordable tube/valve amps go, Jolida makes two models under $1000US. I don't know how much power you are looking for. The 102B has 20wpc, and the 202B has 30wpc. They retail for $580 and $750 US currency. A screaming bargain if ever there was one. Cheers! |
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Gold Member Username: John_aPost Number: 2783 Registered: Dec-03 | Thanks, Rick. I checked Jolida and they are more expensive over here, I think, but I will re-check. Those are good prices. There is import and the different mains voltage and frequency to consider. You have the 102B, right? I would tend to go for 40 wpc at least, I blew up my 40 wpc transistor amp in 1992. However, this thread makes me think a valve Watt goes further than a transistor Watt. As it were. In local yellow pages I also see a company with the name and logo (a sine wave) of my old amp, "Armstrong"; it advertises repair of older UK gear. I will check that out too. The sister Armstrong FM tuner, even older (1979), is now in daily use again, and sounds superb. |
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Silver Member Username: Rick_bNew York USA Post Number: 804 Registered: Dec-03 | John, I had a hard time believing that 1 watt of tube power equals 3 watts of transistor power. I can't believe the headroom. I have a reason for keeping with a lower power tube amp, but will explain more as my tubes "come on song". I think with tubes less is more. Cheers! |
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Gold Member Username: John_aPost Number: 2784 Registered: Dec-03 | Rick, Cheers. I read with interest, and look forward to more from you, here, on "Old Dogs", or anywhere my radar picks up. Here we have Jan who writes better than the guys in HiFi News and knows more; you, Rick, and Kegger, who know your stuff, too, and are recent converts. I wonder, has anyone tried tubes/valves, found them wanting, and returned to solid state? |
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J. Vigne Unregistered guest | John - What next, a recommendation for a subwoofer cable? You know none of us out here can give advice on what will be best for you in there. I'm curious as to why the suggestion would be made to take your speakers with you when auditioning the Prima Luna. Since it is April in Dallas before we get the March issue of HiFi News in Dallas, I would appreciate your ideas. I mean, why not take your dog with you? Much better hearing; if Fido starts to howl, it puts a kibosh on the deal. What salesman can counter that argument? You might even want to attach a small battery to a tender part in case the sales closers come fast and furious. If poochie should lift a leg on something, suggest the shop not carry that line any longer. John, you've read enough to take a qualified approach to upgrading your system. Which do you think would be the best route? Do you think your present system has much more to give that would justify the speakers first? Or, are you at the point where getting more information, more coherently to your current speakers would be the largest improvement? Column A or column 2? Very simple. I know your speakers and I know which way I would go. As to the room and inviting your speaker to join you on an afternoon outing; PSHAW!!! You know what music should sound like, and you certainly know what your own discs should sound like. The reason, I am going to guess, HFN wants you to take your speakers is to see if; A) the balance of the two work well together for someone used to transistors (what you hear will be the amp and not the speakers) or; B) your speakers present a load the amplifier might not care to drive as most less expensive tube amps don't make lots of current. In terms of "B", you have nothing to consider; your speakers are quite an easy load. For the room and "A", there is nothing to get used to here. It is a dodge to think otherwise. This is how you go about it. Take an afternoon when the shop is likely to be quiet and give the manager a call in advance. Explain what you want to listen to and that you'll have your own music. Ask for a salesperson who has a knowledge of the old KEF's and have the manager set up an appointment to listen to a few items. The manager will pair you with the right salesperson and have everything arranged when you arrive. Listen to a few speakers to get an idea of the room and equipment then ask to listen to the tube amp with the speakers you and the salesperson decide are most like your own or most to your liking. Nothing exoctic in speakers at this point. That's it. Inquire about their home audition policy and go from there. You can still audition other amps as long as you make your intentions clear to the shop should you decide to audition their amp at home. While we're at it, let me make another suggestion to you. Unison Unico. Valve front end and MOSFET outputs. Reasonably priced in Europe. Finally, I believe the current philosophy on the length of a piece of string could be equated to the matter of "how long". The answer, in contemporary ideology, is "as long as is necessary and not a bit longer" despite the number of knots and frays along the way. |
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J. Vigne Unregistered guest | John - Shall we begin a new thread for the UK minded? We could title it "Valve Verbage". |
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Gold Member Username: KeggerMICHIGAN Post Number: 2182 Registered: Dec-03 | Well john: "So I was thinking, pardon the newbie question, I am new to all this; will I get better sound from changing to a valve amp (with 1980 KEF Corellis on flower pot stands), or from getting, say, a used pair of Quad ESL 63s speakers for about the same price? My present system is all over the place. For the first time for many years I can afford a little upgrade and self-indulgence. Say 1 k£. Both options have negative WAF, but the WAF and HAF are closely linked, so, if it is really good, we will both end up in credit. (This is how it should be, imho). Or should I swallow my pride and go SACD? My Rantz has nearly convinced me to give it a go. [Will respond on other thread, MR; thanks; have read; little time]." My thinking would be, what is the weekest link in your system. And with your equipment you've mentioned to us I'd say you have good sources. You have some good speakers. Well that leaves the amp. I would think you'd get the most improvement in a nice tube amp over an average at best transistor amp. Now that is my observation of your system, what is yours? |
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Silver Member Username: Rick_bNew York USA Post Number: 805 Registered: Dec-03 | John, I would have to agree with the Senators from Texas and Michigan. |
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Gold Member Username: John_aPost Number: 2785 Registered: Dec-03 | J. Vigne, Thank you. I am at work but will read and reply, later. But I note "I know your speakers and I know which way I would go." and that is rather what I was hoping for. Of course I will make allowance for your coordinates on the Political Compass, Italian ancestry etc. (HiFi News writers seem to drool over Italian tube amps., but from the way they write, it seems to be more about style than substance.) I am not in a hurry re upgrades, but all views greatly appreciated. There are actually quite a lot of dealers around here. I am going to take my time and find out more about them. I visited one last week. Interesting. I meant to scan the Prologue Two review and "The Story of Surround", but forgot to bring the mag today. Will try to remember. I recommend buying the mag, but if you actually cannot do that until months after the cover date, it hardly seems immoral to want to spread the news when it is news. I had years paying 5-10 x the cover price for outdated newspapers and magazines. What a pleasure to be back in the real world; that is how it seems. No offence to Texas. Also a fine place. |
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Gold Member Username: John_aPost Number: 2786 Registered: Dec-03 | Thanks, Kegger; my post crossed yours. Thanks also, now, Rick. It is getting late and I must head off. Will come back to this. Promise. Thanks for all views, guys. |
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Silver Member Username: Two_centsPost Number: 457 Registered: Feb-04 | John A., I'm also in the process of upgrading my stereo system and going down a similar path as you. There's so much to share. First, the tube amps you're considering are all getting rave reviews, especially the Primalunas. If you read between the lines of the reviews, this is what I get: The Primalunas are fantastic entry level amps for those just getting into tube equipment. They're easy to use, rather foolproof, and extremely well-built at their price point. But if you're thinking that you're getting the best tube sound at such a low cost, then you're mistaken. There are better tube amps out there, but you have to pay a lot more. I spoke to Kevin Deal who is the North American importer of the Primalunas and although he had wonderful things to say about the Primas, he had even more wonderful things to say about the Carys (and Audio Electronic Supply, which is a subsidiary of Cary). The catch is you have to spend at least double to get better performance than the Primas. There are significant differences between the Prologue One and Two that could help in the decision. The Two cost US$250 more than the One. For the money you get some upgraded parts and 5 more watts of power (not insignificant) produced by KT88 tubes versus the EL34 tubes used for the P One. There's one group of tubeheads that swear by the EL34s and another group that thinks the KT88s sound the best. It's a matter taste I suppose. A neat thing about the P Two that isn't mentioned in the reviews is that you have the option of using EL34s as well as the KT88s. So you could roll different tubes to see which you like better. The P One doesn't provide this option. If it means anything to you, one of the Brit mags, Hi-Fi+ maybe, named the P Two their product of the year. The Icon Audio Stereo 40i is also an interesting choice. It's basically the same design as the Primaluna amps. What it adds is the ability to switch from triode mode (19wpc) and ultralinear mode (40wpc). From what I understand triode mode will provide a sweeter, airier midrange while ultralinear mode will provide better dynamics and top and bottom extension. The Primalunas operate strictly in ultralinear mode. So which amp you choose will depend on the speakers you have. I've decided to select my speakers first and then try to match the amp to it. That's probably the first question to ask if you're upgrading more than one component. Which component are you going to build the rest of your system around? From my experience, the speakers are the most critical part of an audio system. They make the biggest difference in sound. Finding the right speakers I think is paramount. I'm sure others would disagree, especially those who subscribe to the garbage-in-garbage-out argument. They would place the emphasis on source equipment. Although the argument sounds good in theory, I've found that in actual listening tests great speakers with decent source equipment sound better than decent speakers with great source equipment. |
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Silver Member Username: Two_centsPost Number: 458 Registered: Feb-04 | One more comment: I recommend buying speakers used. They depreciate in value substantially and are the least likely component to break down. |
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Gold Member Username: KeggerMICHIGAN Post Number: 2183 Registered: Dec-03 | 2c I feel the same as you in the regards of speakers importance. But having said that I also believe with every component in the chain theres a point when "better" to me does not outway the cost. So I go for the speakers I like that don't break the bank and then my components have to be on that same level of quality where the next step up is a big change in price with minamul gain. So my thought for john was he has the nad dvd-a/cdplayer and a nice turntable so the upgrade from there would be a decent price increase and the same for his speakers. But the amp I believe would be very signifacant increase in quality comparred to what he has. I believe he would have to spend a lot more money on anything else to get the same amount of improvement he'll get from the amp. So I guess for me it's not where you start your system but how best to upgrade when you allready have a system together. And to me that means amp for john. But that is just my oppinion! In the end as long as all the pieces fit doesn't really matter where you start. But if I was building from scratch I would get the speakers I want and build from there to match my system up. And agreed this goes against the norm but I'm very picky with speakers. And if I had to limit my choices by the gear I have then I wouldn't be happy! |
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Gold Member Username: KeggerMICHIGAN Post Number: 2184 Registered: Dec-03 | Also when I'm making speaker choices I like to try and stay at 6-8ohm and at least 90db efficency so it doesn't limit my amp choices to much either! |
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Silver Member Username: Two_centsPost Number: 459 Registered: Feb-04 | Kegger, everything you wrote makes perfect sense. I agree 100%. It makes sense to replace the weakest link in the system to get the greatest immediate improvement. |
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Gold Member Username: MyrantzPost Number: 1370 Registered: Aug-04 | [My UK brain cannot filter out further associations of "tubes". Not all pleasant. I suppose this madness could be prevented from speading, if people get their tubes tied. Or snipped. Hope you do not mind "valves". What are they called in Aus, MR?] Well John, in years past we have called them 'valves' or 'valve amps' but I would not be surprised if they were now known as 'tubes' or 'tube amps' as we seem to have a need to copy just about everything US. I mean we even have halloween here for heaven's sake. Probably won't be long before we're walkin' around like bow-legged Texans wearin' ten gallon hats - we're already big on line dancin' too ya know - Yeee bl00dy ha! IT'S VALVES YOU GUYS! The only tube part is that glass cylinder on the outside of that internal electrical stuff so: Tube = the outer shell of the valve. So there you have it - tubes have no gutz - just empty cylindrical shells - therefore you must be enjoying empty sound! Grin, laughing, smile, nudge - nudge, wink, wink! |
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Gold Member Username: John_aPost Number: 2787 Registered: Dec-03 | MR, "Halloween" is OK. I think they call it "Walpurgis" over there. Yes, "valves" makes more sense. It is what they do: the current goes only one way. I shall use "Valves". 2c, Thanks. Really. Over here, the Icon Audio Stereo 40i is the same price as the Prima Luna Prologue Two. I recall J.V.'s comments on triode mode. There is a cheaper 40ie without the tape out and the triode option. I am inclined to think I would have to spend an awful lot to improve on the KEF Corelli speakers. They come from the time when KEF made drivers for many great designs, including the LS3/5a. There is something about the sound from those speakers I recognise and like, almost whatever input I give them. Jan says he knows these speakers.... Again, little time. A lot to do tomorrow, too. But will be back. Thanks, all. PS As some may recall, I have 5.1 system I am pleased with, but it is not where we live at the moment. I thought it might be good to see how far stereo will go, in the interim. I have enjoyed some music here more than I have for many years. Could be the small room. Could be "absence makes the heart grow fonder". Could be living somewhere I like. I have stopped my sweep through the wonderful Lindsay Beethoven String Qt. cycle, after Op. 95 "Serioso" and before the first late Qt., which is Op. 127. The reconrdings and preformances are so good, I want to get it all right before making that step. Wonder if anyone can relate to that...? |
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Silver Member Username: Two_centsPost Number: 460 Registered: Feb-04 | Let's straighten out something else while we're at it: A bonnet is something you wear on your head, not something found on car. |
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Gold Member Username: MyrantzPost Number: 1372 Registered: Aug-04 | While we are setting the records straight: A trunk is a large suitcase, or organ hanging off an elephant's face, not the space in a car meant for carrying a trunk. Everyone knows that space is a boot! And looking under the hood! What - are you people over there per-verts or what? |
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Gold Member Username: John_aPost Number: 2789 Registered: Dec-03 | Right on, MR. They will catch on eventually. Why, they used to say "Automobile". Meaning "car". And a "Fender" is a guitar; not a "bumper". Windscreen, windshield. Must go. |
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J. Vigne Unregistered guest | And what happens to the valve function if it is not enclosed in something? No vacuum, no valve. No tube (that glass cylinder on the outside of that internal electrical stuff), no vacuum. I suppose we could use one of those Seal-A-Meal contraptions, but that is unlikely to be good for marketing purposes. "Try our new Seal-An-Electron-Flow Mk.II. Very transparent, and very tight. If you don't like the sound, you can cook a steak on it and use it to seal and freeze the leftovers." Just doesn't have a ring to it. John - Out of respect for Kegger's and 2c's advice, I will suggest once again you are a big boy who can make up his own mind. What type of tube, what brand of what type of tube and what color and shape of plate in what brand of what type of tube, etc., etc., etc. will have different opinions when the discussion turns to thermionic valves. I will state my opinion of a matter which I'm certain will bring disagreement among those on the forum. The idea of taking a pentode valve and switching it to triode operation is absurd. A triode is a triode and a pentode is not. This strikes me much the same as disconnecting a few spark plugs from your car's motor or buying a three way lamp and only using the lowest filament. It is pure marketing bullcrap. I have no doubt it can be done and doing such will affect the sound. My question is why do it. The point of a triode is its simplicity. The simplicity in the basic circuit is often given as a reason for tube sound to begin with. The swing back to triodes was to exploit that simplicity to its fullest extent. A pentode was not designed to be a triode with additional elements which can be disconnected. If you want triodes, use triodes. If you want a push-pull pentode amplifier, buy one. Don't go looking for something that does everything and suceeds at only some part of the equation. A V-8 is not just a V-6 with a few extra parts. And thosun of yew who thinks "WALKIN'" is what it's called in Texas, we don't do much o'that round here nomore. That's what them thar' pick 'em up trucks was invented fer. Once yew get yer big, shiny belt buckle 'hind the wheel of a F-250 dually 4X4 Eddie Bauer 'Dishun, them thar leather Captuns seets don't 'llow much in the way o'bowed legs no how. You'll be knocking that thar' Big Gulp right out'n the cup holder thing thar. 'Course you gots to make sure you got the rume fer yer hat still. Yer gonna need somthin' to carry all yer oil money inta the bank. They don' do home pick up nomore. |
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Silver Member Username: Two_centsPost Number: 461 Registered: Feb-04 | I won't dispute the comment that Americans are purverts, in perhaps a closet puritanical way, but I object to calling the trunk of a car a boot! It's madness! A boot is what you wear on your feet, preferably not at the same time you're wearing a bonnet. |
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Gold Member Username: MyrantzPost Number: 1373 Registered: Aug-04 | Texas Jan, Well fer land sakes podner, ah'l be darned if ah kin come up with a rejoinder like that one ya done did there. 2C It comes from back in the old days when you had to give your car a good 'boot' in its behind when it wouldn't start. Makes perfectly good sense :-) The bonnet is the cute little cover we put over our motors to protect them from the elements, like we do for our heads and please don't be mocking them so - we can look darn cute in them! |
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J. Vigne Unregistered guest | Boots and bonnets. That thar sounds like a right fine lil'lady. That is if'n it IS a lil'lady a wearin' 'em. I will agree boots is fer kickin' tho. |
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Gold Member Username: KeggerMICHIGAN Post Number: 2185 Registered: Dec-03 | Jan: "John - Out of respect for Kegger's and 2c's advice, I will suggest once again you are a big boy who can make up his own mind." Appreciated, I think I know what you mean and we've had that discussion on another thread with a certain someone and it got very very ugly! Again just my oppinion and I hope my explanation shows why "I" think that way! |
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Gold Member Username: KeggerMICHIGAN Post Number: 2186 Registered: Dec-03 | Heres another represenative of Tubes! http://www.thetubes.com/sitemap.htm |
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Silver Member Username: Two_centsPost Number: 464 Registered: Feb-04 | Yes, Jan, good point. I've tried to share information on tube amps rather than recommend a specific product. As far as my opinion on speakers being the most important component, it is only that, an opinion. I'm sure others think differently. Got no qualms about that, pardner. |
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Silver Member Username: Rick_bNew York USA Post Number: 807 Registered: Dec-03 | Hi All, Just a few more thoughts for those interested. The more I listen, the more impressed I am with the Jolida JD102b. I now know why it is regarded as one of the more underrated products on the market. I have already contacted Bill Baker at Response Audio regarding his upgrade mods for the amp. That's a future story. I really decided to get a tube/valve amp because I have been listening to both professional reviewers, critics, and fellow audiophiles gush and carry on about them for years. I finally decided it was time to listen for myself. Well, I am glad I did. Simply, there is a harmonic richness and a liquid flow to the music that can not be duplicated by transistors. Before anyone starts feeling uncomfortable, please remember the opinions expressed here are mine, and you certainly have the right to disagree. I won't go on about the "sound" of tube amps, because most of you read the same reviews I do and have. The question that you may have is: is a tube amp for me? My answer to that is yes and no. Please again let me explain my view and I ask you to take no offense. Let me first back up a bit, and go back to the subject of hearing. I have always had a hard time with the concept that not everyone hears the same. So when someone would tell me they didn't hear the subtle differences between interconnects, speaker cable, and tweaks I would think, what is wrong here? Well, not everyone CAN hear them, and that too is within the norm. I am beginning to think those that hear no difference are sometimes better off. I think for them a well thought out and put together mid-fi system is all they will ever want or need. And they will be happy with the sound of that system. I can only imagine being free from upgradeitis. That being said let's get back to the question. If you truly can't hear the differences discussed, then I would say a tube amp is NOT for you. Stick with a quality solid state amp or receiver. I have heard most and owned many. I think McIntosh is as good as it gets. On the other hand, if you can hear the differences in wire and tweaks, and truly know what a wooden tip drum stick sounds like on a high hat or ride cymbal, or pulled a bow across a violin string, or can tell a single coil guitar pickup from a Humbucking from the sound or tone alone, then a tube amp just may be what you are looking for. When doing my research prior to purchase, I chose an amp that was basically a bread and butter design from the 50's and 60's. The bulk of those amps used the EL84 output tube. I have been told by many people that the smaller EL84 has an unmatched sweetness, or more of the tube essence, that the larger EL34 and KT66/KT88's can't match. Again, my feeling that with a tube amp, less would means more. After all, if you really need a 75-100wpc amp, why are you considering tubes in the first place? Remember simplify, simplify, simplify. Man, I wasted a lot of years doing just the opposite. Cheers, and enjoy the music! ps Thank you Jan and Kegger.................. |
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J. Vigne Unregistered guest | Glad you're enjoying the new amp. What's happened to the 6100? |
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Silver Member Username: Rick_bNew York USA Post Number: 809 Registered: Dec-03 | Hi Jan, It's funny you should ask about the 6100. In all my years of audio, my wife has seen a lot of equipment come and go, usually without comment. When I told her I was getting a tube amp, she told me in no uncertain terms, I was forbidden to sell the Mac. I had to laugh that she was that impressed with the sound. I wasn't planning on selling it anyway. I'm sure I can find another room in the house for a Mac based system. |
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J. Vigne Unregistered guest | Your wife obviously has good taste in many areas. |
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Silver Member Username: Rick_bNew York USA Post Number: 810 Registered: Dec-03 | Thank you Jan. I am the lucky one. She's about as good as they get, looks, brains, and the patience to put up with me......LOL! |
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J. Vigne Unregistered guest | I assume she's reading this over your shoulder. Tell her to pincha you chicks! |
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Gold Member Username: MyrantzPost Number: 1386 Registered: Aug-04 | "She's about as good as they get . . . " Rick, I hope you get someone else to write on the gift cards you give to her :-) |
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Gold Member Username: KeggerMICHIGAN Post Number: 2190 Registered: Dec-03 | Well Jan I'm back to using my 5881 based amps again on my main speakers! (the golden tube audio se-40's) I've gotten some nos/used older 6sn7 input tubes to test. And I'm really liking how they sound with newer speakers I'm using since the last time I've used these amps. Plus the new preamp! It's like having a whole new system all over again , Whenever you feel the need to upgrade just move a couple pieces around and do some tube rollin , cheaper then buying new equipment! The main thing I notice the bass is a lot tighter and more in control. Some of these input tubes sound a lot different then others and not just the eq but the image also gets wider and or deeper or more focused. The new ribbon based tweeters love these amps also! Good stuff for me. Hey rick you seem to be quite a tweaker wait till you start tube rolling. Some can call it an obsession or nightmare but I love the changes they can make! |
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Silver Member Username: Rick_bNew York USA Post Number: 813 Registered: Dec-03 | Rantz, LOL! You could be right. The only thing I ever have to do is pull her nice and close and tell her.....................well, I'll let you fill in the blanks. Kegger, Good to hear from you my friend. I'm about to do some tube rolling also. The Electro-Harmonix is described as a darker sounding EL84. It has very smooth bass, but a much more laid back mids and high end. I ordered a matched quad of EI Elite Gold pins. They should arrive along with my multi-meter any day. The only question I have is the Electro-Harmonix came with the amp and are biased at 20mV. The Jolida manual says the unit should be biased between 17-22mV. 25mV maximum. The EI's have a bias point of 40mV. I am right in assuming you bias the amp to the tubes, and not the tubes to the amp? Can you clear this up for me? |
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Gold Member Username: MyrantzPost Number: 1388 Registered: Aug-04 | Rick, I'd better not if we wish to remain friends :-) Well, the tube rolling you and Kegger are talking about I believe is different to the tube rolling I recall from my youth, but similar in the respect that I recall how things would brighten up and glow when I was in the vacuum. And the music did seem better. But, I know when I'm on a good thing I should stick to it. No tubes for me - if I had to find a space on our shelves for all those valves my wife would begin to REALLY wonder if I was of sound mind LOL! Hope you enjoy your latest musical adventure. |
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J. Vigne Unregistered guest | http://www.tubedepot.com/whisbipo.html |
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Gold Member Username: KeggerMICHIGAN Post Number: 2191 Registered: Dec-03 | RICK: "The only question I have is the Electro-Harmonix came with the amp and are biased at 20mV. The Jolida manual says the unit should be biased between 17-22mV. 25mV maximum. The EI's have a bias point of 40mV. I am right in assuming you bias the amp to the tubes, and not the tubes to the amp? Can you clear this up for me?" I can't see the answer in Jans post "or at least understand" But the bias voltage you read on the meter is not the actual bias voltage. It's a voltage drop accross a resistor that the manufacturer of the amp has determined by adjusting this to a given voltage gives you the correct actual bias voltage in the curcuit. If you change the resister the bias voltage you see would be different so a different voltage would have to be calculated. I'm not sure how a tube company would know what that bias resister is suppose to represent in the terms of actual bias voltage in a given curcuit. So I allways adjust the bias accorging to the amp manufacturer. My se-40s are 62.5 mv according to the manufacturer but the guys at sonicraft do suggest different settings "slightly" for different tubes. So "maybe" the bias voltage setting they are suggesting is based on your amp. But the amps normal bias settings I'm sure would be a fine adjustment. You may want to get a hold of the amp manufacturer and see if they suggest this higher voltage , I assume they would not. |
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Gold Member Username: KeggerMICHIGAN Post Number: 2192 Registered: Dec-03 | Also my impression based on the Eh tubes I've used is they are a very lively tube and not dark at all. But the tubes I've used are not el84's so they may be as described and if you've done enough research you probably know! I like the EI tubes as well , they were very well rounded on all the ones I've used. But I get a bigger improvement/change on the preamp or small signal input tubes then I do on the output tubes. I have 2 sets of tubes for all output and input/preamp tubes for all my amps so getting another pair of output tubes to me is still wanted but if you really want to try and see the difference in tube rolling get some of the preamp/input ones! Well that's my input on tube rolling and if someone else has a different approach I'm fine with that and by all means share with us. |
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J. Vigne Unregistered guest | I linked the site to let you read a bit about bias and the effect it has on the tube itself. Also it correctly indicates that not all tubes that suggest a certain bias voltage may run their best with that exact amont of bias applied. Where you set the bias voltage on any given tube will determine its power output, distortion and headroom. Though tube rolling has become a common tweak among tube users, it is often best done with a few pieces of test equipment (beyond a VOM) to monitor your actual results. By running the tube at a slghtly lower voltage you will often achieve one type of sound quality compared to running the tube at a higher or lower voltage. After the joys of tube rolling are experienced, you can begin experimenting with bias voltage rolling on a given tube in a certain amplifier. In some cases the result of increasing or decreasing the bias voltage can give significant changes in sound quality. Of course, the hotter you run the bias, the more you shorten tube life, risking premature failure at the extremes of the bias range. By decreasing the bias voltage you will typically extend tube life (think of putting a dimmer on a light bulb) but may get to the point where the music suffers. Some of the old time tube people I worked with adjusted bias by the glow of the filament instead of the voltage on a meter. They knew the amp and the tubes rather well to do this properly. You do adjust the bias to the tube within the range the amplifier manufacture allows by their circuitry. The idea that you can simply replace any EL84 with another EL84 is a bit too simplistic to be considered a hard and fast rule. Different tube manufacturers will set their limits for the various voltage and current specifications for their own tube; often this will be a matter of the difference between a 6L6GC and a 5881. Broadly there are accepted substitutes that can be made within a tube type. You should always check a few numbers before you order a replacement tube to make the most of the circuit the amplifier uses. Typically plate voltage and bias voltage are the most important. Increasing the amount of either figure beyond the manufacturer's specifications will surely cut tube life. Running either at substantially lower voltages will affect the tube's performance. Not all amplifiers can increase the bias voltage enough within the limits of the trim pots to accommodate all tubes. Even if the trim pot allows more voltage, it may not be desirable to put the stress of higher voltage on other components within the amplifier. You could easily blow out a bias resistor with too much voltage. That's never much fun if it takes a tube along with for the trip to the great beyond. At this point I would call Jolida or your dealer and verify whether the tubes you ordered are a good match for your new amp. You may find the amp can run these tubes but will not produce its rated power and distortion specs. As far as where the most benefit is obtained when swapping tubes, my experience has been it is largely dependent upon the equipment. Some products respond more willingly to different tubes while some are less inclined to show differences. Obviously affecting the signal at its earliest stages will give a significant change to the overall system. Hope that helps. |
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Gold Member Username: KeggerMICHIGAN Post Number: 2193 Registered: Dec-03 | Yes good points jan! When I rebuilt my se-40's I had to change the bias voltage resister so I could use other tubes and have them bias correctly! "not the resister that measured the voltage drop but the actual resister that changes the amount of voltage to the tubes. As you mention some require more or less voltage. |
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Silver Member Username: Rick_bNew York USA Post Number: 815 Registered: Dec-03 | Thanks Guys......and please excuse my ignorance. |
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J. Vigne Unregistered guest | We all start somewhere. |
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Gold Member Username: John_aPost Number: 2794 Registered: Dec-03 | Just to say thanks for all replies. If anyone would like a scanned version of the Prologue Two review or the "History" of surround, drop me a line. Thanks for the comment on switching pentode-triode, Jan. I am not sure they do it that way, though, with the same valves/tubes: www.iconaudio.co.uk Thanks, 2c, also. Yes, we are following parallel paths. Rick, With a good stereo amp and spare speakers, consider connecting your CA Azur DVD-A player (do you still have that?) to four-channel, feeding two stereo systems, one in front an one behind, and setting the player controls to "no sub" and "no center". Just to try it. I persist in thinking surround should be given chance on quality gear before we all join Jan and the HFNews cynics. |
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Gold Member Username: MyrantzPost Number: 1392 Registered: Aug-04 | Unless you have full range speakers - you need the sub - period! |
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J. Vigne Unregistered guest | "Thanks for the comment on switching pentode-triode, Jan. I am not sure they do it that way, though, with the same valves/tubes: www.iconaudio.co.uk " From the icon audio web page: "New versions of Stereo 40i with KT66 and KT88 valve options. Following on the success of the Stereo 40i with EL34 valves, we are introducing 2 further variations with KT88 and KT66 valves. Why? you may ask.. Well The KT88 has a big following. As the last major new valve to be introduced in 1957, it probably has the cleanest sound due to its "Kinkless Tetrode" design and high power, quite different from the EL34. With Ultralinear and triode switching (42 & 19 watts) once again you have the choice of operating modes. On the other hand some regard the KT66 as one of the most musical valves ever made. The lower powers available (again in Ultralinear and Triode modes, 30 & 15 watts) make it ideal for more efficient speakers." John - My read on this is they, like most other amplifier manufacturers offering this switching between pentode and triode operation are using the same tube, in this case either a KT88 pentode or a KT66 beam power tetrode, in each case. The switching to triode operation is done by eliminating the parts of the valve that are additional to the basic triode configuration which, when used, create a pentode. http://www.vacuumtubes.net/How_Vacuum_Tubes_Work.htm If you're interested to read the linked article, you will see a triode is the simplest form a valve with amplification properties can possess. A triode, such as a 300B, will contain three elements. First,there is a cathode which is often referred to as the filament or heater; next will be the anode, or plate; and, to give some control over the emission flow between these two electrically charged portions of the valve, there will be a (control) grid. This type of construction is also found in most of the small signal tubes used as pre amp and driver tubes such as a 12AX7. In the case of the small signal tubes there are often dual tube parts which can be split to use as two separate valves or combined in parallel to lower the output resistance of the circuit. The next step in getting more power from a tube is to add a screen grid which accelerates the flow of electrons from the anode to the cathode. This acclereation gives additional gain to the valve. Some tetrodes are termed beam power tubes, a 6L6 is a typical beam power tube, a KT66 is the valve equivalent. These tubes use a beam plate to confine the electron flow. (Stray electrons will be a reason for making a pentode.) By confining the flow of electrons into a beam, the beam power tetrodes have lower distortion than a typical triode or pentode. By adding another grid called the supressor grid, whose function it is to collect stray electrons, the tetrode is turned into a pentode. The pentode's claim to fame is a powerful tube with less noise than a standard triode or tetrode. 6550 and KT88's are pentodes along with the ubiquitous EL34 and its little cousin the EL84. By switching out the energizing voltages to the screen and the supressor grids, a pentode is reduced back to the three basic elements of a triode. This reduction results in a loss of power and, to some extent, an increase in noise. The higher distortion of a pentode remains though this can be dealt with in other circuits. The current trend in true triode amplifiers is to fall back to the most essential elements of a tube amplifier's design. A single valve is operated in a single ended, thus pure Class A configuration, with no global feedback. This results in an amplifier which is low powered and has as many drawbacks as advantages. The major advantage, however, is the simplicity of the circuit. A SET amplifier uses a minimum of parts that are in the signal path. How the Audio Icon amplifiers and most like them begin life is as a push pull, Class AB amplifier with both global and local negative feedback. Switching out the two extra grids in the pentode valves will not strictly turn this amplifier into an SET with the benefits of the simple circuit. Though some benefits of the simpler triode operation will inevitably exist without the extra grids in the circuit path, the overall design remains very much as it began. It remains a push pull, Class AB amp with some amount of feedback. Other than marketing to people's interest in triodes, I see no reason to sacrifice what is good about a beam power tetrode or pentode valve just for the sake of a switch. If I read Kegger's notes correctly, he has modified one of his Dyna amps to triode operation. If this is the case, he might wish to make a contribution to this discussion. The modifications to the ST70 that I've run across are permanent configuration changes and are not accomplished at the throw of a switch. Still, the result should be basically the same in either case. |
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J. Vigne Unregistered guest | "Unless you have full range speakers - you need the sub - period!" My LS3/5a's shivered when I read this to them. |
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Gold Member Username: KeggerMICHIGAN Post Number: 2194 Registered: Dec-03 | Jan: "If I read Kegger's notes correctly, he has modified one of his Dyna amps to triode operation. If this is the case, he might wish to make a contribution to this discussion. The modifications to the ST70 that I've run across are permanent configuration changes and are not accomplished at the throw of a switch. Still, the result should be basically the same in either case." Almost, I have a new input board on one of st70's that uses 3 12at7's in triode operation instead of the original board with with original 2 tube 7199's. I have the info for the triode mod but havn't done it yet. I will try it some time though! I do like the idea of switching back and forth between triode and pentode. If you feel the "correct" way to run the tube is in pentode then that is fine and you can leave it that way. But if you'd like to get a taste of triode you just flip a switch on the other amps and try it. No harm done. |
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Silver Member Username: Rick_bNew York USA Post Number: 816 Registered: Dec-03 | John, I thank you for your suggestion. Yes, I still have the CA Azur. I use it in my 5.1 system for DVD video. I am, and will always be committed to 2 channel stereo for music. Period. Cheers! |
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J. Vigne Unregistered guest | Kegger - What mod kit are you using for the switch to triode operation on the ST70? |
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Gold Member Username: MyrantzPost Number: 1399 Registered: Aug-04 | "My LS3/5a's shivered when I read this to them." Better take 'em to a speaker shrink! |
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Gold Member Username: KeggerMICHIGAN Post Number: 2195 Registered: Dec-03 | Jan: "Kegger - What mod kit are you using for the switch to triode operation on the ST70?" I'm using the tubes4hifi board for the frontend I'm not doing triode with the st-70 yet, just the replacement frontend board that uses 3 12at7's. I have the instructions for triode mode but haven't done the mod yet. But I will some time down the road. This "I do like the idea of switching back and forth between triode and pentode. If you feel the "correct" way to run the tube is in pentode then that is fine and you can leave it that way. But if you'd like to get a taste of triode you just flip a switch on the other amps and try it. No harm done." was refering to my rogue audio 88 amp. That's all sir. GU day aye! |
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Gold Member Username: John_aPost Number: 2795 Registered: Dec-03 | Unless you have full range speakers - you need the sub - period! Thanks, My Rantz. It depends on what we mean by "full range". In my opinion, there is not much an active sub adds to most music with speakers such Rick's Spendors or my KEF Corellis, both -3 dB at around 50Hz I think. When you get to - 3 dB at 40 Hz (as in my "mains") you can flip between sub on and sub off (the latter giving the LFE channel to the "mains") and be very hard pressed to tell the difference. And, like the centre channel, the sub brings in a whole range of complications. This is for most music. Movies are a different question. This is my estimation. Jan would go further, I think: the LS3/5as roll off at about 65 Hz, I think. That is still not "small", where the low-frequency roll-off is typically 85 Hz or above. Rick, Thanks. I know there is a strong "back to basics" feeling that surround is all hype and stereo is sufficient for serious listening. All I would say is you have a true DVD-A player and can give it a try if you feel so disposed. Nothing is lost (and maybe somthing gained) by instructing the player to feed the centre and sub channels to the main speakers. Many of the best DVD-A discs are in 4.0 in the first place. This is the original "Old Dogs" topic, of course. Jan, I admit I was considering the switchable triode mode a desirable "feature" of the Icon Stereo 40i. Their 40ie does not have it, and is considerable cheaper (2/3 the price). I am more informed now. As always! Many thanks. |
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Gold Member Username: KeggerMICHIGAN Post Number: 2196 Registered: Dec-03 | John agreed your speakers go that low but in my opinion unless they have a large driver or multiple smaller ones "full range" imo they work to hard to produce frequencies under 80Hz and that is where I agree with rantz. Just about all bookshelf/stand mounted speakers with there single 8" drivers or less can benefit greatly from a sub with not trying to reproduce those frequencies and concentrate on what they do well with leaving the sub to do what it does well. So It's not the specs that say it -3db at 50 hz that matter it's how hard it is working to produce that. And a sub works much less because they are generally larger and has a driver that has a higher xmax factor so they are much more effecient in what they are doing and achieve better results,more impact/speed/feeling. "Xmax = Linear (one-way) travel of the cone. Xmax is used to determine the maximum linear SPL capability of the driver, and can be defined in a number of ways. The DUMAX definition is objectively the best one, and it is defined as the shorter of the Xmag and Xsus values, in each direction of cone travel. This definition is more useful than the older definition of Xmax, which was solely dependent on the length of the voice-coil vs. the length of the gap." "Xmech = Maximum physical excursion capability of the driver. Exceeding Xmech normally results in damage to the driver. " Driver moving to much in one direction to complete the task asked of it. Regardless of whether it can do it , if it's not designed to do it but continues to do it will damage the driver and or create distortion. A smaller driver unless it's a sub is not designed to handle a large excursion. "Why should you build a subwoofer? Well, frankly most loudspeakers, particularly the smaller ones, are simply not capable of reproducing the lower bass frequencies (no matter what the specifications claim). If the loudspeakers are relieved from trying to play the lower bass frequencies, they will sound better at higher volume levels. Finally, a subwoofer can be located anywhere in your listening area, which provides you with much more flexibility in positioning your main loudspeakers for good sound." Just a sub page that suggests some simular things as to my suggestions. http://www.diysubwoofers.org/ And john you say a sub makes more problems and is tougher to integrate along with the center channel. I disagree, with a meter or just your ears and the test tones people usually have no problems and get great results. Now if you dislike them for whatever reason that is fine but when setup and used properly to me thay make a huge positive difference with a little effort and care taken plus the correct choice for your application "but isn't that what we should do with all our equipment" Anyways just my 2cents on subs and centers again. To each there own I guess , but I see a big positive influence when utilized. |
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Gold Member Username: MyrantzPost Number: 1400 Registered: Aug-04 | Thanks Kegger, you explained that so well. My mains roll of at 50hz and I've listened to hi-res DVD-A and SACD in both stereo and surround, with and without the sub which accepts the levels below 80hz (the default crossover point in both the SR-7300 and the DVD-2900. Not only does the sub add what is missing - even when speakers are set to large - but it does something wonderful for the other frequencies. I guess your explanation explains that. And this John: "Many of the best DVD-A discs are in 4.0 in the first place." Well, if you've heard them all I could possibly accept that - actually no I couldn't, but I could validate your opinion. Maybe 4.0 is okay for chamber music or such. Sorry for being so direct in that previous post - I meant to put a smiley there :-) |
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Gold Member Username: MyrantzPost Number: 1401 Registered: Aug-04 | I know this a "toob" thread - my apologies, but re: the full range spaker comment: http://www.stereophile.com/loudspeakerreviews/361/ |
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J. Vigne Unregistered guest | "Better take 'em to a speaker shrink!" No, I'd rather not. They are quite small enough right now. I'm not looking for Larry's Orbs. As a footnote, I'm not even going to mention to my 3/5a's Larry's modification to his surround speakers. I do occasionally read them reviews of the large floor standers that cost multiple tens of thousands of dollars. When the reviewer gets to the flaws in the bass response or the coolness of the midrange, I swear I can see those little Rogers speakers smile a self satisfied grin. |
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J. Vigne Unregistered guest | This is "Valve Verbiage" and the discussion of subwoofers should take place elsewhere, but ... I have noticed several things happening in the past ten or twelve years; most of which, I would assume, have been the result of the HT market. Subwoofers have become an accepted manner of getting bass response. People think they can achieve 25Hz bass notes in their room. There is the idea that quite a bit of music exists beneath 50Hz. And, finally, vented boxes are the norm for the new designs. The lack of sealed box speakers has amazed me the most. I understand the Thiele/Small alignments have made it easier to predict the bass response of a vented speaker, but the laws of physics that dictate a vented box will have a 24dB rolloff beneath its port resonance are still in effect. A vented box can be flat to 60Hz but will be -12dB at 45Hz. Not very useable bass. A sealed box which is flat to 60Hz will be -6dB at 45Hz. That places any harmonic doubling of frequncies beneath 60Hz at a still listenable range. And there is no port noise from a sealed box. There are only a handful of instruments that actually produce information beneath 50Hz and the use of those instrument's lowest registers is rather uncommon. The idea that a 25Hz note with its over 45 foot wavelength can be unleashed within a 14 X 19 X 9 foot room is a bit beyond belief. Less than half a wave length does not equal bass; it does amount to standing waves. As Kegger has pointed out to SM on Old Dogs, most subwoofers have a distinct one note bass response. The reasons for this thumpy bass are many, but cost can, to some extent, get beyond the one note bass. It's just that it really costs to do bass response correctly. Not that many years ago it was thought quite unfashionable to combine a subwoofer with a satellite speaker. There were many attempts over the years to mate subs with speakers that had limited bass output below 50Hz such as Quads and the little 3/5a clones. These attempts most often resulted in somewhat deeper bass response but seldom did they achieve better bass response. And the box for the sub was never a small enclosure, which made placement a problem. The integration of a small, light, stiff woofer or electrostatic panel with a larger, heavier, ultimately more flexible woofer just didn't make for a cohesive pairing. The placement of the woofer was always a problem and more often than not resulted in phase inaccuracies and cancellation of freqeuncies. The inevitable problems another X-over introduced only made the situation worse in most cases. I don't think digital X-overs in the processor have done much to solve the phase problems in most low to medium priced equipment. The idea that most people settle for less quality in the bass than they do in any other region is more the answer here, I think, The largest problem that I've experienced with subs is the number of trade offs you have to make when you bring one home to meet the prospective mates. It is an issue of for every benefit there will be a disadvantage. In my case the bads out weigh the benefits. To add to the problem, the 3/5a's are notoriously difficult to match to a sub. Even those people who wouldn't think of trading their BBC monitors for anything else are divided over the use of the Roger's designed subwoofer that was meant specifically for the 3/5a. That sub, the AB1, incidentally used another 5.25" B110 KEF driver for the subwoofer's sole driver. No 12" sub for this speaker. There is a place for a subwoofer and I have one in my HT system. When I just have to hear pipe organs or the car on the Mercury disc I use that system. For my main music system I will, once again, remain an old stick in the mud and keep my 3/5a's and Spicas subless. |
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Gold Member Username: KeggerMICHIGAN Post Number: 2197 Registered: Dec-03 | I know I keep wanting to stop talking subs in tube talk thread too but it looks like were stuck for now. Jan: "That sub, the AB1, incidentally used another 5.25" B110 KEF driver for the subwoofer's sole driver. No 12" sub for this speaker." Agreed that gives you two 5.25" drivers to do the job not one. "There are only a handful of instruments that actually produce information beneath 50Hz and the use of those " Agreed but there is a sound/impact that's there just like the upper frequencies past our hearing or the instruements but were not going to cut off our tweeters at 12k either. I believe thats were most of the "air" comes from simular to what a sub does to the low notes, just extends whats there a little deeper. I have quite a few bookshelve speekers and some get quite nice bass, even so I feel they improve with a sub. As far as creating problems I disagree. Just sit in the listening position and adjust the sub just to the point where you notice it then back it off a tad. I don't care if my sub is off if I'm somewhere else, I'm only concerned with my listening position. And I feel the benefits of the sub outway any problems they may cause as per my other posts. So I think we can give many oppinions and facts to state about subs but in the end it comes down to personel preference again I guess. Now for me I've got a dbx subwoofer processor that I route to a standard amp then out to my subs. This thing has all kinds of adjustment levels and works really nice to dial anything in. I picked it up because I really enjoy deep bass but wanted to really have some nice control over it and it's served me well. Peace out! |
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J. Vigne Unregistered guest | Kegger - Agreed that it is one of those personal preference things, but let me clear up a few points you make. The sub for the AB1 doesn't give me two 5.25" drivers doing the same frequency other than over the limited area of the X-over. The lowest frequencies are still handled by one small driver. The point I was trying to make was the compatibility of small, light, rigid and fast drivers mating well with larger, slower, less rigid drivers with more mass. I understand the numbers in your example, but they represent a worst case scenario. If I'm not looking to drive my speaker's voice coil beyond the physical limitations of the magnetic gap, the numbers are just numbers to me. I don't listen loud enough to make the problem of overdriven woofers a concern. In the example of the roll off at the high frequencies, I have to agree there are harmonics that extend upward to infinity. When a bass note is struck, stroked or blown, the harmonic structure doesn't descend in the same fashion as it ascends. And certainly the information below a note that isn't struck is of little consequence to me. That was my point, there is little information beneath 50Hz that is used as the fundamental in most music. Most of what I listen to has information that does not contain fundamentals beneath 50Hz. If someone else listens to music that has substantial amounts of fundamentals beneath that point, they can decide for themself if the tradeoffs of phasey, erratic, one note bass is for them. And if you don't hear the bass from a subwoofer as phasey, erratic one note bass, you're OK. Once again we seem to have one group who have made up their minds in one direction and another group who think differently. |
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Gold Member Username: KeggerMICHIGAN Post Number: 2198 Registered: Dec-03 | Agreed Jan And I'm glad we can agree to disagree. I see and understand your point and see that you see mine. As you know for me I do listen at moderitly louder volumes and the overexcursion factor does come into play for me. And My music tastes being different I'm sure contribute to my fealings also. I'm glad we can understand each others position though. And maybe we can put this sub thing to rest. GET ON WITH THE TUBE/VALVES! JAN are you interested in the triode mod for the st-70 or just curious as to what I was doing. Because when some other projects get done I will try it. |
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J. Vigne Unregistered guest | Just curious. I miss the little fellas and want to know what's going on in their life. |
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Gold Member Username: KeggerMICHIGAN Post Number: 2199 Registered: Dec-03 | The one with THE new board I had recently taken it to a local guy who builds and repairs tube amps. We added a little more capacitance to the power supply on top of what the board mod allready did. Then we put it on the scope. He showed me a wave form at a certain frequencey "can't remember which" that was out of shape as he has the same board mod "lucky for me" and has showed it to the board maker that he replaces two caps with a different value and it clears it right up. Then he load tested it and we got 42 watts a side with a very clean output from get this 7hz to 30k we were both impressed with the testing and the listening results. I use both amps in my surround setup and occasionly they see mains duty as I'm constently reevaluating these amps/speakers/preamps. You know once you change one thing you run the rest of the gambit through the paces to see if something that use to sound the best in the system still does because now you changed something. I love having all this equipment and changing things. It's like constantly getting a new system but all your doing is moving things around or changing tubes! FUN FOR ME! BUT MIGHT BE A NIGHTMARE FOR SOMEONE ELSE! "as some like to set it and leave it" But I can't leave anything alone. The amps have a good home Jan and are used on a regular basis! They are much appreciated. They've had some work and will get more! But right now they run fine with no issues! OOOAAHHHH THE HORROR IT NEVER ENDS!!!!!! |
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Silver Member Username: Rick_bNew York USA Post Number: 818 Registered: Dec-03 | TUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUBES Good! |