Archive through December 13, 2006
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Gold Member Username: NuckPost Number: 3182 Registered: Dec-04 | Linguistic persnickities aside, how do you find the crop, Jan? |
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Gold Member Username: John_aLondonU.K. Post Number: 4327 Registered: Dec-03 | Yes, I thought of the "Drop in pair" and wondered if this was a deliberate ambiguity. Stirling network may have good lawyers who have advised that "V2" is enough to distinguish this speaker from the real thing, and I doubt if BBC would care, anyway, these days. Extreme conspiracy view: the bass reflex port is there so no-one could say they were trying to pass this off as a licensed LS3/5a. Don't laugh.... There is a story in Sound Bites about a popular UK loudspeaker of the 1950s. It had three drivers. One did nothing, and was not even connected. Why? Three-driver speakers were classed as "professional" and thereby subject to a lower rate of tax than two-driver speakers, which were classed as "domestic". |
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Gold Member Username: Rick_bOrlando, FL Post Number: 1392 Registered: Dec-03 | You both could be right. At this point in time, the BBC has a who really cares attitude, and who is willing to play for a meaningless license? Does it really matter? For the price of the Stirling's, you can buy a pair of the originals on Audiogon. And for anyone who has stumbled upon the BBC sound, like John's Quads, has stopped shopping for speakers. |
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Gold Member Username: John_aLondonU.K. Post Number: 4328 Registered: Dec-03 | That's right, Rick. I could defend the license fee but that's another topic. Anyway I doubt it has long to live. If I were going to get an LS3/5a I would probably want an original, like Jan's Rogers. That's what I did with the Quads. It helped to know that Quad is still there and will service anything it ever made. For a new LS3/5a, true to the original, the Spendor would be an excellent choice, I know. |
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Gold Member Username: NuckPost Number: 3235 Registered: Dec-04 | Check...check...a1 a2 a1234 |
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New member Username: Bill_cPost Number: 1 Registered: Jun-06 | In the interest of keeping this thread alive, I have a couple of questions I thought I would toss out there. The first may be a dumb one, but I was curious as to whether or not you could use both the 4 ohm and 8 ohm taps on a tube amp in a biwire set up. Would this harm either the amp or speakers? The second question is: Are there any tube amps known for producing better low end control and depth than most? I'm presently looking at inegrateds in the $1000 - $3000 range. the only tube amps that I have heard that seem to perform well in this dept. are McIntosh which tend to be a bit beyond my budget at this time. The last question is: are there speakers other than single drivers and horns that are known for being an easy load and that mate well with tube amps? Thank you for any help you may be able to provide. -Bill |
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Gold Member Username: John_aLondonU.K. Post Number: 4377 Registered: Dec-03 | Nuck, Testing, testing... Bill, Thanks. I am fairly stumped by your questions. Concerning no. 1. One can use either 4 ohm or 8 ohm taps, but no-one should connect both output taps at the same time; the instructions should say this. Transformers do not work that way. I think that, if it worked at all and did not blow a fuse (or worse) on the amp, the 4 ohm output would be essentially short-circuiting the 8 ohm output. As regards the others questions, I think "soggy bass" is not a problem with push-pull (i.e. most) tube amps, and they will also drive "difficult" speakers at least as well as solid state amps. Real experts please correct me if this is wrong! |
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New member Username: Bill_cPost Number: 2 Registered: Jun-06 | John, Thank you for responding. I had read somewhere of someone using both taps with a ss amp, but they never described the results. So I was just curious as to what would happen. Thanks for your other comments as well. -Bill |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 8812 Registered: May-04 | . John is correct about not using both taps. However, the two taps will not "short" one another. All the taps are "hot" any time the amplifier is running. The more basic issues of impedance and feedback become the problem. Using both taps will place both sections of the output transformer in parallel with one another. This will cause the amplifier problems when dealing with back EMF created by the motion of the speaker cone(s). Most pentode based tube amps have the feedback circuit located at the highest impedance tap. By using both taps you would "confuse" the feedback circuit and the amplifier is probably going to go into oscillation. This is particularly true should your amplifier have the feedback circuit input located at the sixteen Ohm tap and you choose to use the eight and four Ohm taps for your speaker connection. This situation can vary with the topology of the amplifier but there is no need to use both taps for bi-wiring. There should be plenty of room on any terminal post for two connectors. If not, you might want to reconsider bi-wiring with that particular amplifier. I'm not certain where you would have seen a suggestion for using both "taps" on a solid state amplifier. The advantage of transistors is their ability to be direct coupled to the speaker. Probably you saw a reference to someone using both A&B speaker terminals. That is quite different than using two taps off an output transformer. In most cases transitorized audio equipment (for the consumer market, at least) has the output transitors connected directly to the speaker terminals and they are not running through an output transformer. (Pro audio operates differently in that these designs often use distribution transformers [25 or 70 volt transformers are typical] connected directly to the output transistors. There is then a matching transformer at the speaker inputs to step down the voltage. This helps minimize signal loss over long speaker cable runs.) Mcintosh has remained one of the very few consumer audio companies which maintain "autoformer" coupled amplifiers in their solid state line up. However, the same cautions apply to their ss amps as I've stated above for tube amplifiers. http://www.mcintoshlabs.com/autoformer.aspx By most engineers' standards bass control is a function of output impedance at the amplifier's terminals played against the actual impedance of the loudspeaker at low frequencies. Of course, there's more to it than just this simple equation but that is the gist of how an amplifier controls the low frequency driver. Part of the equation lies in your third question. Tube friendly speakers are more likely to allow a tube amplifier to have better control than a tube "unfriendly" speaker might. A simple change to an acoustic suspension enclosure with its inherently minimal single peak in the low frequencies (system resonance) will show the amplifier a quite different load than a bass reflex design. The BR enclosure has a twin peak of substantially higher impedance points that will be generally unfriendly to the tube amplifier. If someone says they think all tube (or [auto]transformer coupled) amplifiers have sloppy bass, they have never heard a well matched speaker with a well designed transformer coupled amplifier. This can get into a very long discussion regarding output impedance, phase angles, enclosure types, bi-wiring, EMF and feedback and also transformer construction. There really is no need for that at this point. Suffice to say, if a tube amplifier has a reasonably low output impedance (approximately 0.3 Ohm or, better yet, lower), the amplifier will stand a good chance of having decent control over most friendly loudspeakers. Most tube amps tend to fall at output impedances above that 0.3 Ohm point over most of their range. You do have to consider an output transformer is a coil, which is an inductor (which in effect is a potentiometer and/or a filter), which has inherent resistance and impedance which changes with voltage level through the coil. And, of course, the output/input impedance is relative to the frequency at which you measure. The more expensive the tube amplifier, the more likely it is the designer has put some effort into the transformers. Anyone who spends time around tube amplifiers realizes the transformers play the largest role in the sound quality of the final product. Both power and output transformers are important as the nature of tube amplifiers begins with where and how the tubes draw voltage and current from the various taps off the power transformer. This is one reason many of the classic amplifiers from the past are still considered to have excellent potential. Most of the truly great tube amplifier manufacturers of the Golden Age either understood transformer design and construction (McIntosh, Marantz, Citation, etc.) and had their transformers custom (hand) wound or were transformer designers and manufacturers themself before entering into component design (Dynaco). Transformer designs such as the now ubiquitous UltraLinear tapping and the more expensive McIntosh based Unity Coupled designs came from this time period. The Quad Current Dumping design also originated at this time though these variations all owe a debt of gratitude to Blumlien's work in the 1930's. As has been discussed on these pages, you can utilize the various taps on your tube amplifier's output transformer(s) to alter the sound of the final product. Lowering the connection to the four Ohm tap will sound different, with the same speaker load, than using the sixteen Ohm tap. However, the better beginning point is to use a "tube friendly" loudspeaker. Such designs are relatively even in their impedance swings and have little (most horn loaded designs and simple crossover designs) to no (most single driver, dynamic driver designs) negative phase angle. They are resistive rather than reactive loads. Contrary to what you might assume, sensitivity in the speaker is not a pre-requisite to use with a tube amplifier, if, that is, you are using a modern pentode based, push-pull output stage. (Single ended, OTL and triode output stage amplifiers are another few pages of discussion and, once again, are not going to be considered here.) One of the most tube friendly speakers created in the last half century was the BBC designed LS3/5a (which actually has a very complex crossover just to disprove any theory that claims universality). It is rated at 84dB and was, in its original incarnation, a 15 Ohm nominal design. There is an article in the archived pages of this thread where tube friendly designs were discussed and the impact they have on sound quality was dissected. If you are serious about spending upwards of $3k on your amplifier, you might consider one of the classic McIntosh power amplifiers. Many can be had in good working order for less than your stated price limit. Most of the McIntosh designs had variable input level controls (a wire wound potentiometer based "volume control"). Depending on the rest of your system and how it is set up, you could run a CD player directly into the amplifier and use the front panel "volume control" to adjust levels. Or, you could run a tube power amplifier with litle more than a 100-150kOhm pot as a passive pre amplifier until you could afford a decent active or truly well designed passive pre amplifier. Passive pre amps have been discussed in the "Pre amp" section of the forum. There are both positives and negatives to using a passive design. In the case of the Mac tube amps, the biggest drawback is their 0.75 volt, laboratory standard input sensitivity and their 250kOhm input impedance (the latter being a negligible "drawback"). There are also plenty of contemporary tube integrated amplifiers to consider at that price range. At the moment, the Chinese manufactured goods are offering quite good values should you choose to spend your money there. . |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 8813 Registered: May-04 | . I guess I should clarify that most solid state amplifiers do not actually have their output transistors "directly coupled" to the speakers. There are typically blocking capacitors to eliminate DC and/or protection networks such as Zobels which are between the transistor's outputs and the speaker terminals. The term "direct coupled" has been bastardized in this way for ages however. . |
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Gold Member Username: John_aLondonU.K. Post Number: 4382 Registered: Dec-03 | Bill, Remember I wrote "real experts please comment"! Seems this thread is alive. Jan;- you refered to at least two achievements of the HiFi News "No. 1" name.... |
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New member Username: GonzofuPost Number: 1 Registered: Jul-06 | So much information, so little time to wade through it all. Any of you *philes have site that describes some of the terminology and basics of getting into tube amps. I had an old Traynor guitar tube amp and aside from lugging it to and fro the gig the thing was the cat's pjs. I now want a stereo tube amp but its hard to find a buyers guide -- most are aimed at those who know. Thanks for the help! http://www.equalsopposite.com/word/ http://www.equalsopposite.com/php/phpBB2/index.php |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 8814 Registered: May-04 | . Refer to my list of sites on this thread: https://www.ecoustics.com/electronics/forum/home-audio/243686.html . |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 8815 Registered: May-04 | . As with most things audio, there are no pages where I can send you to learn everything you need to know about tubes. This thread contains some very good information and I would suggest you invest some time reading the archives. For the most part learning about tubes is a matter of doing it and listening to those who know. Putting "audio vacuum tubes" into a search engine and then wading through the various sites is another way. My bookmarks for "tubes" is filled and yet manages to grow every week. Finally, as you learn about tubes; the more you know, the more you know you need to know. . |
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Gold Member Username: NuckPost Number: 3262 Registered: Dec-04 | Wow, Jan nice post. The more I know about beer, the more I think I know I need one to reread those links. Thanks. |
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New member Username: Bill_cPost Number: 3 Registered: Jun-06 | Thanks Jan, But do you think you could elaborate a little on that? Just kidding. Wow, so much to learn. Thanks also for your advice regarding classic Macs. If you recall from a previous post of mine that you responded to I had been considering a new MC275. I tried listening with a CD player plugged directly in and using the Mac's input level controls as a volume control. Didn't sound so good to me. Sounded great with the Mac pre amp however. Can't afford both at this time. Is there an inexpensive pre amp out there that could do it justice in the mean time? Also, I listened to a Cary SLI 80. I did like the sound in triode, but missed the bass that it seems to sacrifice. Very different sound from the Mac. Not sure which I prefer at this point. Someday hope to have both but that will be far into the future. Lastly, can you harm the MC275 by running the CD player directly into it? Thanks, -Bill |
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New member Username: GonzofuPost Number: 2 Registered: Jul-06 | Jan, Thanks for the insight. I wasn't trying to get anyone to dumb it down, if thats what was infered. Thanks again. -gonz http://www.equalsopposite.com/word/ |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 8818 Registered: May-04 | . You won't harm the Mac by playing the CD directly into the front inputs. If the output voltage of the CD player exceeeds the overload point of the Mac, you will get distortion. As I said you can use a passive pre amp in between the player and the amplifier. A passive unit can be nothing more than a volume potentiometer. Wire up a small box with input/output jacks and make your connections to the volume control inside the box. Voila! A passive pre amp. . |
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New member Username: Bill_cPost Number: 4 Registered: Jun-06 | Thanks again Jan, If I use a volume potentiometer as you suggested, how would that differ from using the input level controls? Is it likely to sound different? Also, would a tube buffer accomplish the same thing, in addition to the effects of the tube? Does a tube buffer provide gain as well? Thanks, -Bill |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 8819 Registered: May-04 | . "If I use a volume potentiometer as you suggested, how would that differ from using the input level controls?" Other than giving you the ability to choose the resistance of the pot there should be little difference between the McIntosh potentiometer and the passive set up. "Also, would a tube buffer accomplish the same thing, in addition to the effects of the tube?" What effects of the tubes? If you're looking to get "tube sound", then I guess you could add the buffer. This "tube sound" seems to be the scheme of these items. If the buffer has a level control of some sort, then it functions much the same as a tube based pre amp without significant gain. Most tube buffers I've seen have 2-3dB of gain. The idea is merely to run the signal through some tubes to get the effect of "tube sound". In case you didn't know, I'm not a big fan of "tube sound". . |
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Silver Member Username: RavbainsMelbourneAustralia Post Number: 154 Registered: Mar-06 | I am not sure I like to put things serially into the signal path, since I don't really see how an extra buffer or gain stage can make things better, if you haven't "got-it" in the first place. Some people like these tube buffers, so if they like it, who am I to tell them what to do? Am I missing something here? I am yet to hear an amp using valves in its output stage, that can pin me to my seat and leave me totally punch drunk, when listening to high energy rock/pop like Muse or Placebo for example. But I know I can get this effect when I listen to a solid state power amp from Gryphon, or Krell FPB series for example. The properties I like in these amps is the speed, and the impact, which creates an effect similar (although of course not as massive) to what I hear when I go to a rock concert (since the music is reproduced and not truly 'live' or acoustic). So for the time being I am sticking with a sand based amp. I am probably too un-couth in my taste in music..... |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 8820 Registered: May-04 | . "Other than giving you the ability to choose the resistance of the pot there should be little difference between the McIntosh potentiometer and the passive set up." I should elaborate a bit on this statement. There are some terrific passive units on the market. Staying with a "simple" potentiometer design, you can wire up a stepped resistor, ladder-type volume control. This sort of "pot" places only one resistor (per channel) in the signal path. The simplicity of this approach offers levels of transparency far beyond even the best of the Noble or Alps potentiometers. However, the basic limitations of passive pre amps still remain with this approach and ladder-type pots run about three+ times the price of the best Noble pot. A few designers are now turning to autoformer or transformer based passive pre amps. These are more expensive than the ladder-type pre amps for the same reasons I laid out in the post on tube friendly speakers. The quality of the X-former determines the quality of sound; and good transformers are not cheap. However, several of the limitations of passive pre amps are erased or diminished with these units in line. Either of these approaches to a passive pre amp would be superior in sound quality to either a simple 100kOhm pot in line or the gain control on the front of a power amplifier. . |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 8821 Registered: May-04 | . RB - No one here insists everyone likes tube amplifiers. Most of us using tubes actually feel as if we have a secret that other folks haven't caught onto yet. And, should you discover tubes, you will merely be taking away our chances for some really great NOS tubes. However, when I hear someone say they haven't been pinned to the wall by a tube amplifier playing high energy music, I usually think they haven't heard the right amplifier with the right speakers. There are more than enough tube amplifiers which prefer to rest upon the ideals of "tube sound". They will not pin you anywhere. You will be sewpt away on a sea of lush, sweet soundscapes. And, for some shops, this is what they feel they want to present as an alternative to soild state. It makes for an easy alternative choice for the consumer. For the most part though, vacuums should sound not that different from sand if both are true to the source. Unfortunately, if a shop doesn't promote tubes and a salesperson doesn't understand tubes, it is too common to find a 60 watt tube amp connected to a pair of Thiels or some other God-awful tube unfriendly design. I have long felt speaker designers and amplifier designers never speak to one another and one doesn't give a rip what the other designs. Add a salesperson/shop who doesn't know enough about tubes and you will get less than stellar performance from a tube amplifier. Salespeople tend to sell what they prefer for themself. If a salesperson has the attitude that all tubes have loose bass, that salesperson will usually never attempt to find out why that is and how to correct the situation. As to solid state amplifiers leaving you "punch drunk", I can understand that impression. . |
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Silver Member Username: RavbainsMelbourneAustralia Post Number: 158 Registered: Mar-06 | Jan, no worries, I don't feel that I am being assimilated into the valve culture. Likewise I feel no need to apply any cultural force in the opposite direction. If I keep going with my DIY experiments, I may look at valve based cicuitry, since as I have mentioned once before, I don't think I can cope with SMD technology. (I may be able to drag solder the odd chip, but that's as far as it goes...) Anyhows valve or sand based I am happy with what I am hearing at home for the moment. cheers Rav |
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New member Username: Bill_cPost Number: 5 Registered: Jun-06 | Thank you as always Jan, Can I ask you what your experience has been with different preamps with your MC 240's? Have you found the Mac pre's to mate best, or have you had good experiences with others? If I go the Mac route I'll probably pair it with an active pre when I can afford it. The other thing I was considering was a CD player with a volume control. I've never used one so I don't know how they perform. Would that be the same as just adding the volume potentiometer as we discussed? Or do they perfom other functions similar to a preamp? Thanks, -Bill |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 8822 Registered: May-04 | . The volume controls included in CD players are typically pretty cheap items and should easily be bettered by the gain control on the Mac or a good Noble or Alps pot. Otherwise, you could consider the vc on the player to be a form of a passive pre amp. The term "pre amp" is a misnomer in many cases if the piece of equipment has no phono section. While an "active line stage" might perform some gain functions, typically a line stage needs no additional gain over and above what the CD, DVD, tuner or tape would output. The benefit of an active stage is usually limited to switching functions and the buffers at the outputs to maintain a constant impedance. Not all pre amps employ buffers. Some active pre amps will include filter caps at the inputs to block any DC offset that might come off the outputs of a source player. So, active units have their place and are often the best choice for simplicity and safety. I've had many pre amps with my Mac amps. To say which I prefer would be to tell you what pre amp I now own. Not much point in that. Find a pre amp which suits the character of the power amp you buy. You establish what characteristics you prefer, I do not. Play to the strengths of the system and don't use any component as a BandAid for another component's problems. . |
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New member Username: Bill_cPost Number: 6 Registered: Jun-06 | Ravinder, Thank you for your comments. I doubt that I would use the tube buffer, but am curious about how they work. I understand what you say about the qualities you mentioned provided by your SS gear. And I agree that those qualities are missing from some of the tube amps that I have listened to. However, in my very limited experience, I've found that the McIntosh amps that I've heard were not lacking in those areas. And even the tube amps that were, I've found qualities that appealed to me that the SS amps in the same price range that I've heard do not have. Just a matter of personal taste. Ultimately I'd like to find gear that can provide the best of both worlds (budget permitting). Thanks, -Bill |
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New member Username: Bill_cPost Number: 7 Registered: Jun-06 | Thank you Jan, I think I'll need to go back and review some of the old threads on active vs passive line stages. Thanks again, -Bill |
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Silver Member Username: RavbainsMelbourneAustralia Post Number: 161 Registered: Mar-06 | Hi Bill, thanks for your comments, ...interesting. If I get a chance I will, one day, go and listen to some McIntosh amplifiers. There is a McIntosh dealer in Melbourne, and the proprietor of this dealership is a true gentleman. But often times you visit the store and he is not around. If I get a chance I'll give the Mac's a good listen. -best regards Rav |
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Gold Member Username: John_aLondonU.K. Post Number: 4390 Registered: Dec-03 | Rav, That sounds like a good shop. I think I mentioned before that Audio Research makes tube amps with transistor-type power ratings. BTW all this talk of sand - is there an audiophile niche where people long for the authentic sound of the germanuim semiconductor? No, thought not... |
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Silver Member Username: RavbainsMelbourneAustralia Post Number: 166 Registered: Mar-06 | Very nicely put John ;-) Maybe I will start this this club of subversives... I have really enjoyed the visceral sounds emanating from most notably: Karan, Gamut and Gryphon... It would take quite some amp to disgrace these happy monsters. Levity aside, I guess the key point is to find good equipment which acts as a faithful servant to the music regardless of the technology employed. Also, I am quite aware of ARC amplifiers, they have quite a reputation that precedes their products. Never had the pleasure of an audition though. cheers Rav |
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Silver Member Username: RavbainsMelbourneAustralia Post Number: 170 Registered: Mar-06 | Jan, I forgot to say that your responses are poignant as ever, I was about to post this, but somehow something failed. cheers Rav |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 8827 Registered: May-04 | . Damn! Where did that Indian put my silver bullets? |
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Gold Member Username: NuckPost Number: 3331 Registered: Dec-04 | Beside the Coors, Kimosabe, 2nd shelf beside pickles. |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 8828 Registered: May-04 | . Thanks, didn't know we had any pickles left. |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 8829 Registered: May-04 | . Thanks, didn't know we had any pickles left. |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 8830 Registered: May-04 | . That's the way to get those numbers of posts up. |
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Gold Member Username: John_aLondonU.K. Post Number: 4392 Registered: Dec-03 | That mask must getting in the way of the keyboard... |
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Silver Member Username: HannjeffHalifax, Nova Scotia Canada Post Number: 119 Registered: Jun-06 | What are some good (affordable*) tube buffers. *Affordable is under $600 |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 8831 Registered: May-04 | . The only unit I'm aware of at this time is the Musical Fidelity product; if it is still in production. Tube buffers were never a must have item in audio and were only introduced a few years back by MF. Though the claims of superior sound quality after passing a signal through a vacuum are obviously overwrought, most people on the forum report their original MF tube buffers are now residing in a closet somewhere waiting for a day of resurrection to save the soul of some misbegotten, pagan-heathen solid state breathin' source player. Kegger had reported buying a similar product that apparently is now also out of production. I don't remember anymore about that adventure. I would save my money for a product which actually does something in your system other than take away cash which could be better spent. . |
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Silver Member Username: HannjeffHalifax, Nova Scotia Canada Post Number: 120 Registered: Jun-06 | Would running my analog sources through a tube amp do a similar effect? |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 8834 Registered: May-04 | . I'm sorry, you'll have to describe what "effect" you mean. |
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Gold Member Username: DakulisSpokane, Washington United States Post Number: 1025 Registered: May-05 | Could you guys just give a brief synopsis of the last 1800 plus posts so I can catch up real quickly? And, pass the pickles, please. |
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Gold Member Username: NuckPost Number: 3482 Registered: Dec-04 | hehehe |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 8883 Registered: May-04 | . "Could you guys just give a brief synopsis of the last 1800 plus posts so I can catch up real quickly?" Tubes gooooooood!!!!!! . |
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Gold Member Username: NuckPost Number: 3487 Registered: Dec-04 | next question? |
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Gold Member Username: Rick_bOrlando, FL Post Number: 1402 Registered: Dec-03 | Eloquent as usual Jan! That about sums it up. Anything else we can help you with Dak? |
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Gold Member Username: NuckPost Number: 3489 Registered: Dec-04 | Eloquent as usual Jan! That about sums it up. Anything else we can help you with Jeffrey? |
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Gold Member Username: John_aLondonU.K. Post Number: 4432 Registered: Dec-03 | Whats better - Tube or Solid State Amp. I linked Tube Talk there, and Nuck mentioned it. Just for the general good. "Not enough Watts" seems to be the main consumer resistance to tube amps. I file it under "reasonable but wrong", along with "not enough decibels" for electrostatic speakers. Put the two together and you'd expect real problems. Quite the opposite. Dak, "And, after all our wanderings, we arrive at the place where we started, and know it for the first time". |
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Gold Member Username: KeggerWarren, MICHIGAN Post Number: 2741 Registered: Dec-03 | Just checkin in again, not much goin on here, everyone else? More mind finagling work on my amp today, but I love building this thing from scratch and scraping parts together from all sources even old TV's, LOL! Take care. I'll get over to Dogs soon to. (I know I have some catchin up to do over there with well wishes and whatnot) |
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Gold Member Username: Rick_bOrlando, FL Post Number: 1405 Registered: Dec-03 | What's up Kegman? Are you still building the perfect beast? LOL! |
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Gold Member Username: KeggerWarren, MICHIGAN Post Number: 2742 Registered: Dec-03 | Actually Rick I as just thinking of you, we'll need to chat here soon. OH now I'm using simulation software to redesign the circuit and see what shakes out. I mocked up something that's a little unconventional but looks nice on paper though at least. |
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Gold Member Username: NuckPost Number: 3755 Registered: Dec-04 | lay it out, Kegger. |
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Gold Member Username: KeggerWarren, MICHIGAN Post Number: 2743 Registered: Dec-03 | This is the rough draft of the front end. The output section is pretty straight forward, and it's the phase splitter and drivers that are most important in an amp. IMHO It's a modified Cathodyne followed by a differential amp but also has a tail like an LTP design would, kinda different then anything I've seen. Seems very very stable on sims and works well with many B+ voltages. The pic sizes here are awfully small so it may not be to easy to follow. When I take out all the meters and redo the lines it may look better,I'll post another. Driver/phase spliter is a 6J5 then the differential is a 6SN7.  |
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Gold Member Username: KeggerWarren, MICHIGAN Post Number: 2744 Registered: Dec-03 | The 6SN7 is shown as a pair of 6J5's (There each one half of a dual triode 6SN7) |
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Gold Member Username: KeggerWarren, MICHIGAN Post Number: 2745 Registered: Dec-03 | Oh yes don't forget the importance of the power supply as here there will be 2 one for the output section and one for the front end with plenty of chokes. |
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Gold Member Username: John_aLondonU.K. Post Number: 4475 Registered: Dec-03 | Kegger; I'm just curious, what is the simulation software? I have not seen a valve/tube symbol for years. Since way before desktop computers. |
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Gold Member Username: KeggerWarren, MICHIGAN Post Number: 2746 Registered: Dec-03 | It's called Multisim, which isn't designed directly for tubes really but for you to model electronic circuits in general but has some tube models so you can build. I just downloaded the 45day trial version to see how it worked and I liked it. Unfortunatly it's a professional program and it's around $2000 which I aint got, so after this I will be investigating others, there is a student version which I will look into. There are many similar SPICE type programs out there that will let you do the same |
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Gold Member Username: John_aLondonU.K. Post Number: 4482 Registered: Dec-03 | Thanks, Kegger. Yes, programs like that can be really expensive. I see Multisim is National Instruments. |
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Gold Member Username: Rick_bOrlando, FL Post Number: 1406 Registered: Dec-03 | I'm with you Kegger. Just let me know. |
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New member Username: AuggieBrusselsBelgium Post Number: 1 Registered: Nov-06 | Hello, anybody there? I just finished going through this whole thread (it took me 2 weeks) and now that I come to the end of it I see that it's been over 3 months that nobody posts here anymore. Before I start I just wanted to say thanks to all of you for sharing your expereinces, John A., two cents, and all the old dogs. Anyways if someone is still there, I just wanted to say that after reading tube talk, I have finally decided to buy the Prima Luna. I am a newbie, about a month ago I decided I need a good HiFi. Initial budget around 1500 euro. I made a list of all the shops in my area and began auditioning NAD, Cambridge, Rotel.. basically all the shops were proposing the same material. Until one day I walked into this last shop on my list. After I told him what I was looking for he told me that I came back in about an hour he would make me listen to something which I would never forget. He showed me the Prima Luna and I was a bit skeptical, I had heard about tube amps but I thought they were just stuff for excentrics. I went back after an hour and I must say i was literally blown away. I auditioned the Prologue 1 with a cambridge CD player and AE EVO 3 speakers. At the end of the session I asked if a better CD player would make a greater improvement so he plugged in the Ah! Njoe Tjoeb 4000. and WOW what an improvement that was. This is a little over my budget now but I think it's worth it. I know, I'm a newbie, so anything i listen to sounds great. But this is not the case. The next day I went to audition for a second time the Rotel 06 amp but it didn't do anything to me. I just felt like leaving right the shop and go home and do some research on the Prima Luna. That's how I came across tube talk. I have been literally feeding off this thread for about 2 weeks now and just when I was ready to post I see that it is dead. Anyway if someone is still there, do you have any comments on the Ah! Njoe Tjoeb cd player? It really sounds great and I probably going to buy it but I just hoped to hear what you guys have to say about it. |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 9366 Registered: May-04 | . Tube Talk ain't dead. It's just resting until it's needed again. Glad you found us. |
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Gold Member Username: ArtkAlbany, Oregon USA Post Number: 3682 Registered: Feb-05 | Agostino I hope you decided to buy the PL1 it is much more natural sounding than the PL2. My local dealer has sold 2 PL2's (one to me and one to an employee) and now has both of them back and can't sell them. There is something about them that just never quite sounds right. John A will probably disagree and that is his experience but my advice is to stick with the PL1. Good luck and enjoy. |
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Gold Member Username: John_aLondonU.K. Post Number: 4582 Registered: Dec-03 | Ah, that's good to read, Agostino! Thanks for posting. This thread started when Rick Barnes decided "tube talk" was getting in the way of discussing stereo and surround sound on "Teaching an old dog....." I can hardly believe any one has read the whole thing, in one go. I was very sceptical about tubes, originally, but thought I'd give it a try. I can't comment on the PL1 against the PL2, Art. I had advice from two dealers, independently, that my speakers would need the extra power of the PL2. Let us know how you get on, Agostino. I read good things about the Ah! Njoe Tjube. That's all I can say about it. |
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Gold Member Username: NuckPost Number: 4629 Registered: Dec-04 | It's alive! That sounds great Agostino. The whole thing you read? Looking forward to a new tube amp meself. Will post. |
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Gold Member Username: Rick_bOrlando, FL Post Number: 1417 Registered: Dec-03 | Happy to see this thread active again. Wishing all a Happy Thanksgiving. |
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Gold Member Username: NuckPost Number: 4638 Registered: Dec-04 | You too, Rick. I am flying out of Indy today, back to Toronto, so no turkey here(had ours last month), but happy cranberries all around! |
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Gold Member Username: John_aLondonU.K. Post Number: 4586 Registered: Dec-03 | Happy Thanksgiving, all. It is a fine tradition, celebrating something uniting a nation, and a festival safe from charges of political incorrectness. Our local park had a big fireworks display recently with no reference to Guy Fawkes. Agostino, the December HiFi News has a strong recommendation of the Icon Audio 60. Switchable pentode (60 W)/triode (30 W). |
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Gold Member Username: NuckPost Number: 4659 Registered: Dec-04 | http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem%26item%3D300047815355&ssPageName=AD ME:B:EOIBSA:CA:11#ebayphotohosting This little darlin' should show up here around Tuesday. It is a bit small, but nice looking, I think. For 30pounds(80$) I hope it works well. |
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Gold Member Username: NuckPost Number: 4664 Registered: Dec-04 | Is there a 1-2-3 to installing new tubes or pre clearing the unit before first power-up? I sure hope this amp has been powered up already. It seems a good candidate should I decide to start tinkering a bit. I will check for shorts and inspect the soldering beforehand, of course. Do the tubes need to be handled with gloves or cleaned? |
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Silver Member Username: My_rantzAustralia Post Number: 947 Registered: Nov-05 | If it sounds as nice as it looks Nuck, you'll be laughing. |
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Gold Member Username: NuckPost Number: 4676 Registered: Dec-04 | It's maybe a trailer queen...will post. Shite, it's prettier than me. |
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Gold Member Username: John_aLondonU.K. Post Number: 4587 Registered: Dec-03 | Looks like a Pathos amp, what that strip of wood. Good luck, Nuck! |
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Gold Member Username: Rick_bOrlando, FL Post Number: 1418 Registered: Dec-03 | Good luck Nuck....... Please remember rule #1 with tube amps: NEVER turn on the amp without having the speakers hooked up. NEVER, NEVER! Enjoy. |
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New member Username: AuggieBrusselsBelgium Post Number: 2 Registered: Nov-06 | I did it. I went to audition the primaluna amps again and I ordered the PL1, along with the Ah! Njoe Tjoeb. I also ordered the AE Evo 3 speakers. I will have everything for next weekend. Needless to say I can't wait. John, thanks for the tip on the Icon audio. I read alot of good things on this amp but I was not able to find it anywhere in Belgium. |
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Gold Member Username: NuckPost Number: 4682 Registered: Dec-04 | Auggie, is this your first tube set-up? How are you fixed for interconnects? |
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New member Username: AuggieBrusselsBelgium Post Number: 3 Registered: Nov-06 | Nuck, yes this is my first tube set-up. I got some YBA interconnects and Liberty cables for my speakers. I don't know much about interconnects so I trusted the dealer on this one. |
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Gold Member Username: John_aLondonU.K. Post Number: 4590 Registered: Dec-03 | Au; Yes, Icon is mail order only. I bought a PL2 partly because I could purchase from a dealer. You have the Benelux connection, too. Good luck. Report back! |
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Gold Member Username: NuckPost Number: 4755 Registered: Dec-04 | The little Mengyu Integrated is here now in my lap. I opened the think before powering it up, for inspection of assembly etc. I think it was thrown together. The solder may have been applied with a mop and 50w gun. The board is stayed with 3 of 4 screws, the last corner mounting hole being occupied with a tie-wrap holding down an output cap(120u, 400v), as are the other 4. The transformer box is installed on a kilter, with barely enough slop in the holes to align it. All holes for screws are actually elongated slots, allowing for alignment, presumably by the end user. It is a cute little thing, for all that. I am going to power it up today, to the Lings, seeing as we have 3 feet of snow in 24 hrs here, and not much else to do. My 80$ investment will prove itself, or fail, today. |
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Gold Member Username: Timn8terSeattle, WA USA Post Number: 1141 Registered: Dec-03 | For $80 you can't complain too much. There is some nice equipment coming out of China. The interesting part of that is the better units are using time-tested circuits originated from the old school electronics companies like Western Electric. Hard to beat if they're built right. |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 9417 Registered: May-04 | . http://www.stereophile.com/news/120406language/ |
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Gold Member Username: Timn8terSeattle, WA USA Post Number: 1142 Registered: Dec-03 | For example: http://www.sixmoons.com/audioreviews/genesis3/i60.html I've listened to this amp extensively and didn't find it lacking unless you were asking it to try and push a very difficult load into a very large room. |
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New member Username: Bill_cPost Number: 9 Registered: Jun-06 | Nuck, The new MC 275 is calling you! (A mite bit more than $80. though, but worth it.) -Bill |
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Gold Member Username: NuckPost Number: 4767 Registered: Dec-04 | This little amp has a lot of charm. The mids are a little bit pushed, like a 'look at me' presentation, and the bass is muted somewhat. This is my first tube amp, and not a lot invested, as mentioned. The music selection has been limited so far, for a reason. The selections have been of a strange variety today, actually some of the 'lesser' recordings I have. American Pie(Don McLean) and Cover of the Rolling Stone'(Dr Hook) from a compilation cd. A burned mp3 disc with Queen's 'Tie your mother down' and 'Tenement funster'. Basically the worst recordings that I have. By moving and re-moving the speakers, replacing the I/C's(box red n whites) with Goertz zone cables and focusing on different parts of the room, I have gotten the best results that I think I can get with the present set-up. All tracks have been played straight through, no eq. In fact, the pc card is idle, I am using the wma player alone. I have maximized the basics, and will roll in the better stuff as the night goes on. The little IA really does have some great pace, I must admire it for that. At near field listening, the pick-up is great, particularly for tickling piano, and I have perked up more than once listening to Cartoon Classics. $80? okee dokee. |
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Gold Member Username: NuckPost Number: 4768 Registered: Dec-04 | ummm...how hot is this thing supposed to get? |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 9419 Registered: May-04 | . For $80, let's put it this way; have you ever tried to change an exhaust manifold with the car running? |
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Gold Member Username: NuckPost Number: 4785 Registered: Dec-04 | In fact, yes.Ford 460 motorhome setup. Mrs. Nuck is a tad concerned. The smell is one that you and I know well, Jan... Is this a need for concern, you figgur? Is there a fix? I mean the transformer box is fully involved as well. I do not know what to expect. Would a really good tube IA run cooler(without coolers) and would this be a judgement of the quality of a unit, being able to deliver the goods without spontaneous combustion type temps? |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 9422 Registered: May-04 | . You might just be experiencing a "burn-in" period. But any smell of burning insulation is not a welcome thought. Some tube units run quite hot and some run too hot. It is not uncommon for a manufacturer to use a 1/4 watt resistor when the circuit really calls for a 1/2 watt. All just to save a few pennies. Unfortunately, too many of us remember when Ford tried the same approach with the Pinto. Lots of lawyers who specialized in immolation. Pushing the amp toward "hot" could be nothing more than trying to get the best specs possible or could be pushing the amp too hard for its own survival in order to get a little bit better specs and less lifespan. I am going to guess you are smelling the transformers burning in but, if at all possible, try to isolate from where the aroma is originating. Be very careful, remember there is 400-700 volts running through the amp's circuitry. Keep one hand in your pocket. It is not uncommon that you might not be able to touch the power transformer during operation as many tube amplifiers run that hot. The output transformers should be slightly cooler but still might not be cool enough to touch for more than a moment. Obviously touching the tubes themself is similar to touching a glowing lamp and they will expend substantial heat when all four outputs are cranking along. Remember there is 400-700 volts running through the amp. Turn out the lights and check that all the tubes are glowing a nice orange color and nothing is running cherry red. How warm a tube amp runs isn't really a matter of quality but of choice. My Macs run very cool and have lasted for over forty years. During the winter months, I sometimes have had to turn out the lights to make sure the tubes are glowing properly since I feel a room temperature power tansformer down at floor level. But, that's Mac and that MC275 that's supposedly calling you is now over $4k. So, decide how warm you can stand your amp to run. Many CJ and AR tube amps run hot enough to warm a room. Why did you think people traded in their tube amps when solid state came along in 1957? . |
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Gold Member Username: NuckPost Number: 4789 Registered: Dec-04 | I see. I will let it cool down and take another peek inside. I suspect that I will be replacing some wire runs with high temp sleeves. Thank you for the high tension warning, too, Jan, I have my meter handy. For all that, the little amp really is fun. I have gone through the sound card now, and enabled the eq. A 3db boost at 40 Hz and a 3 db cut at 3 and 4 k, and the sound has really come to life. The speakers are spiked to the desk(via hardwood platter) and the setup does not suffer from a lack of power at all. I will try a cdp tonight, likely the Rotel 1072, run straight. The amp has shown terrific pace with my latest 'reference' programs, being John Mellencamp's 'uh huh' and Floyd's 'the wall'. I am enjoying it all. How would I go about tailoring the IA to bring about a little more Bass to the sound? I don't want to mess up the eq too much, I might like a little more presence of body to the delivery. Would a set of KT88's be a replacement for the EL84's? |
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Gold Member Username: Jan_b_vigneDallas, TX Post Number: 9424 Registered: May-04 | . Generally you don't replace EL84's with KT88's. You would have to know whether the amplifier manufacturer has designed in the ability to make that swap. The real difference in the two tubes is in power dissipation, not necessarily in sound. EL84's are on the low end of pentode output tubes in terms of "watts" while KT88's/6550's are at the high end. If the output transformers aren't designed to handle the voltage of the higher power tube, you would be dissuaded from trying that swap. On the other hand, many listeners feel the EL84 is a much "sweeter" sounding tube than the average KT88 and you could be trading away one thing for another. Tube amps are like any other amp, they have what the designer invested in them. Usually it is the power supply which provides "bass", both tightness and depth. If the amp doesn't have the p.s. to produce the type of bass response you want, there might not be anything you can do to really affect a change in the amp's basic character. You can try some other tubes. Chinese tubes are still not known for their warmth and frequency extension for the most part. So, if you have stock Chinese tubes, try a tube that claims a more "vintage" sound. Also, like any other amp, and probably even more so with tubes, tweaks to bring out the best in the amp will be beneficial. Tubes are almost always microphonic and this can give a reduced bass response. Isolating the amp from mechanical and air borne vibration will clean up the sound. Tube amps also suffer from internal vibrations and this might be something you live with until modifications can be made. The way you describe the construction of the amp, I would be looking at cleaning up the wiring and internal parts. Better caps will help with bass response. But any transformer coupled amplifier is going to have to deal with the basic construction of the output transformers. If the designer hasn't chosen an output transformer that can deliver good bass, there's not much you can do to really change the sound of the amp. If there is a capacitor between the output tubes and the transformer, you might have to live with some reduction in bass response. Until I was absolutlely certain the amp wasn't going to let my speakers see any DC voltage, I wouldn't remove any caps to try to get better bass response. But, hey, the speakers are under warranty; right? Every manufacturer gives you one freebie screw up. You never mentioned what the amp is retailed at but this doesn't sound like a high priced amplifier. Bass is something you pay for. That MC275 is calling. . |
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Gold Member Username: NuckPost Number: 4793 Registered: Dec-04 | Oh yeah, Tim gave me a lifetime warranty against stupid. And an 'EASY' button. You and Bill C. are killing me. Yes, I could go MC275, that would be a nice gift for the Divorce Lawyer, and his immediate family. All kidding aside, this little thing is fun. And warm. I have no issues with a nice Mac amp, I always thought I would have a ss Mac, but now I am not so much(wink). Interesting thing about tube based integrated amps from Hong Kong, they arrive without a scrap of paper. None. Nada. Not even a 'thank you for purchasing' spiel. I am absolutely freehand for anything I want to do(which is what I expected), but a scrap of papyrus would be comforting. However, I mailed Kegger, we shall see if he is game. Any and all others willing to chip in will be greeted with an e-mailed drink. |
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Gold Member Username: Rick_bOrlando, FL Post Number: 1419 Registered: Dec-03 | Nuck, Welcome to the wonderful world of tubes. I am going to throw in my two cents for what it's worth. As the owner of two EL84 based amps, I think it is the "sweetest" sounding tube out there. No doubt your amp came with Chinese manufactured tubes. They are IMHO the worst sounding tubes on the market. I don't think you want to go out and spend $500+ on NOS tubes for an $80 amp, so may I suggest starting with the Russian made Electro-Harmonix. Keep in mind that the biggest change in sound will come from the preamp tubes, not the power tubes. I see you have contacted Kegger, so you are in good hands. He is doing some mods to one of my amps as we speak. So start with some simple tube rolling and take it from there. You are in no hurry. Listen and learn. Keep in mind tubes need to "break in", usually 50-100 hours, before they sound their best. Have fun. |
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Gold Member Username: NuckPost Number: 4806 Registered: Dec-04 | Rick, thanks. Yeah, I am in 'kid in a candy store' mode right now. I will check with my dealer on tube options, and yes, Kegger called back right away, willing to help me along. Sweet. I am a couple of hours away from him, I may just pop in(invited, of course). I love the sound and the look of the whole tube thing. Whoop! |
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Gold Member Username: NuckPost Number: 4807 Registered: Dec-04 | The pre tubes are 6N3, Chinese, yes. Any better choices? Or Russian replacements? |
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Silver Member Username: Mike3Wiley, Tx USA Post Number: 219 Registered: May-06 | Nuck, Whatever happened to break in period? Is this a used or demo amp that you purchased? In the link provided by Timn8ter above (http://www.sixmoons.com/audioreviews/genesis3/i60.html ) there is an easy to understand explanation by Gary Koh as to why his amps run cool (see the side bar). BTW did I miss where your new Classe setup lost its newness? You're killing me man, getting my mind on flirting with tubes when my Carver marraige is going so well! |
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Gold Member Username: NuckPost Number: 4809 Registered: Dec-04 | Hey Mike. Yeah the Mengyue is new, and break in(I am told) is 100 hrs or more. Only 200 volts across the plate might be enough for the KT88's that GK is using, but the mods to get to that point are not minor, by the article. Starting with more than a hobby kit like mine likely helps, too. The little Tuber is upstairs, with the speakers in near-field, running off the pc, presently. The big dog is downstairs, unaffected by it all. And speaking of your carver, when are you going to get the other one cleaned up so as to run 2 in mono bridge? The look alone would terrify the neighbors. Or maybe sort out an active XO to run the second set of coils on the speakers with #2 amp? |
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Gold Member Username: NuckPost Number: 4851 Registered: Dec-04 | I bet your Rogue would put some great Bass into the second set of coils! What tube complement do you have in the 99? |
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Silver Member Username: Mike3Wiley, Tx USA Post Number: 220 Registered: May-06 | Dammit anyhow Nuck, the non-refurbished Carver has been in the shipping box for 2 months. I guess its time I get off to Fed-Ex and ship it to Carver Repair in Oregon. BUT I STILL DO NOT HAVE THE 4th ORDER CROSS OVER TO RUN INTO AMP FOR THE SECOND COILS OF MY GALLOS!!! What are you planning a Texas trip to drop in with both Jan and I and want to insure I can have my rig properly set up for the audition? (Just wishful thinking on my part.) It will happen though. Thanks for moving me along my friend. |
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Gold Member Username: NuckPost Number: 4856 Registered: Dec-04 | I do try and help. |
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Gold Member Username: NuckPost Number: 4861 Registered: Dec-04 | http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem%26item%3D280057297635&ssPageName=ME RC_VI_RSCC_Pr4_PcY_BIN_Stores_IT&refitem=280058817357 Not so sure about 89 days, but the amp might be ok. |
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