|
Bronze Member Username: ChuckoyaHamilton, Ontario Canada Post Number: 32 Registered: Jul-06 | does anyone know the main difference between the M400,M400A,M400T is? i am thinknig of buying one off ebay,and would like to know the difference betwen them. Thanks to who evere can help me out |
|
Silver Member Username: Mike3Wiley, Tx USA Post Number: 232 Registered: May-06 | Chuck, I have a pair of Carver M-4.0T amps rated at 375 wpc which I had Roland Barr refurbish one of. That is the one I am using in my "A" set up. Roland can be reached via email at rolland@carveraudiorepair.com or you can check out his web site at http://www.carveraudiorepair.com |
|
Silver Member Username: BasicaudioChula vista, Ca US Post Number: 116 Registered: Mar-06 | The M-400 series is the CUBE design and the lettering is basically minor changes on the amplifier design, but primarily similar in specs like the M-400 the original and the M-400A the successor. The T is the latter series that was designed to sound like TUBES... The m-4.0t is a completely different amp of much higher grade emulating the SILVER 7T AND 9T MONO BLOCKS performance during the time Bob carver was challenging the ultra high end and overpriced manufacturers like MARK LEVINSON etc and actually beating them and several companies in reviewers bench tests in the early 80's. The m-4.0t's are the higher version of the famous 1.0t and 1.5t's which defeated the mark levinson that was ten times it's price range. The m-400 held it's own and was praised by the late genius julian hirsch from the then stereo review, now called sound and vision. It did have some critics but the critics are all idiots and don't have the expertise and knowledge of innovators like bob carver and the late julian hirsch who pioneered audio. There wouldn't be high end as we know it without audio engineering greats like julian hirsch. I generally don't like critics, cause they always look on the negative side and think they know more than the designer. If most of these critics and arrogant audiophiles think they know so much, they would better serve the public by INVENTING their own designs instead of criticizing towards the negative. The m-400 series is a unique design in a small package that was unheard of during that time, even though it used the cheap SPRING CLIPS which was common in the 80's, nevertheless a unique design. The spring clip can always be MODDED anyway to newer terminals and the plugs changed to gold plating. I have both the M-400T AND THE 1.5T along with other carver TFM amps. The carver repair relocated from washington to oregon. They will fix or modify ANY carver or sunfire products but you have to mail to them. I spoke to their technician/customer service before. Design wise there's not much difference as I said within the 400 series, even though the T series is a bit improved based on the 1.5t and up series cause of the TUBE sound. The TFM series of the 90's was based out of the T series of the 80's! I'm using my M-400T as a monoblock for my center since i acquired a sunfire theater grand 2 processor that's new and upgraded to the latest software at sunfire. I have a NAD T773 av receiver as well. Both companies are awesome in their design and no nonsense approach. Japanese receivers and amplifiers and i and owned many like pioneer, kenwood, denon, yamaha DON'T EVEN COMPARE and is more into gadgets and unusuable controls. MOS-FET are very weak, decent for the average listener but that's the reason why audio enthusiast and audiophiles spend the money they do on esoteric brands. Carver and NAD are good examples of high end for average people with average incomes. Krell, ML, CLASSE, MCINTOSH, meridian for example are for those with large pockets. Great companies but outside most people's pocketbook. Germans make great amplifiers too like MBL! I'm a big carver fan because he's a genius and reasonable in designing equipment that's people friendly. Most expensive amplifier from sunfire is only $7000 for those who can afford it, but compared to a $250k krell or mark levinson? that's reserved for the elites... What makes a good manufacturer is accurate bench test, manufacturing process, materials used and information about their products not overbloated and exaggerated claim and advertising! |
|
New member Username: LeonskiPost Number: 8 Registered: Jan-07 | The T-Mod amps were intended to sound like....tubes! Carver used a circuit where he plugged the target amp, maybe a Conrad Johnson or other HI end unit and his amp into the same speaker. Then Adjustments were made and when the speaker produced NO sound, the target amp and Carver's amp were theoretically producing the exact same sound. Sounds a little nutty, but Carver really shook 'em up. I remember hearing a Phase Linear demo with near original Bose 901's! Couldn't afford any of it, but boy was it loud. Currently, my M-400T is near death. It has been on almost continuously since purchase and has been repaired, at power compay expense, once. I guess I'll have to pony up for a replacement? The list is short so I have some research to do followed by a trip to a couple of places for a good listen. Fortunately, one such place also is a Magnapan dealer, so I can hear any proposed amp with the descendents of my MG-1's. One final note. Good Stuff lasts. I have had no need to pour money into this system once it was up and running. But that looks like it is going to change, new amp coming soon. One question, though. Why are MOS-FETs 'weak'? In a proper design, using curve-tracer matched transistors, you should be able to just use more of them? The Cube has 6 devices per channel. I have seen hi-power stuff with heat sinks stuffed with output devices. Is Bi-polar better? just curious, since I am out of loop. |
|
Silver Member Username: JethroLansing, Mi Post Number: 159 Registered: Jan-06 | good info gentlemen |
|
Gold Member Username: Jan_b_vigneDallas, TX Post Number: 9693 Registered: May-04 | . I don't understand your term of "weak" in reference to MOSFET's. Is there a specific function of the device that is considered so? MOSFET's are voltage driven devices, very much like vacuum tubes, and therefore many people ascribe similar attributes to both devices. Like thermionic envelopes MOSFET's cannot pass the large amounts of current which are usually available from more conventional bipolar output transitors. If you are asking a FET amplifier to drive a very difficult load, you will be somewhat disappointed in all likelyhood. In a similar situation a typical bipolar output will have more control of the woofer due to the increased amperage available through the device. The result would be what most listeners consider "tighter" bass response. Since FET's and bipolars both have reasonably low output impedance, the FET can be made to sound more like the bipolar by using more negative feedback. The bipolar cannot be made to sound more like the FET. Bipolars have come a considerable way since the days of the Phase Linear 400 but they still retain a distinctive sound that for many listeners is like listening to shattering glass. MOSFET's on the other hand are well known for their musicality and a "MOSFET mist" that underlies the music signal and turns off many bipolar (transistor, that is) fans. The fact remains, for ultra-tight bass you will do better with a bipolar output device than any other unit in common use. One problem many people have with that fact amounts to the simple notion that ultra-tight bass response is not always what you hear in a live performance and "overly dry" is often the direction most bipolars lean towards. As to how many output devices do you require per channel, the simple answer is one matched pair only for a push/pull output stage. Any more than that makes close tolerance matching difficult if not impossible and will affect the sound quality in mostly negative ways. If you have difficult to drive speakers, you might need the additional power of multiple output devices but the sound quality will almost always suffer in some way. It is not uncommon to hear the lowest powered amplifier in a line sounding the best of the bunch. In this case, "best" would refer to the most musical. . |
|
Gold Member Username: NuckPost Number: 5622 Registered: Dec-04 | Oh sure, it was all fun and games till Jan showed up. How does it sound to you? I had a Marantz amp from 1995, and featured a MOSFET array output stage. The chassis was basically a heat sink/stiffener, with 1/4" aluminum inner chassis. The array reatured 12 FET's per side, allied with 5 seperate cap banks per channel. Large. Heavy. It worked wonderfully when the kettle got on the boil, and WHOOO NELLY did it boil. Like 500wpc into band monitors. It was poor for useful listening. But light it up with the band... |
|
New member Username: LeonskiPost Number: 9 Registered: Jan-07 | Jan, While I understand you to say that more devices per channel degrade the sound, I can't off hand think of a single device (pair) which will sink enough current to drive some really inefficient speakers, not to mention heavily inductive or reactive loads. I suspect modern curve tracers can match 'em close enough for even golden eared people. BiPolar or FET, good designs exist in both camps. OH, I didn't start the 'weak' thing. I was curious why Gerbil Love made that statement. thanks for other info about transistors: |
|
Gold Member Username: Jan_b_vigneDallas, TX Post Number: 9695 Registered: May-04 | . Yes, if you have some very difficult to drive speakers, you will probably need lots of current going into them. My problem with that situation is; why buy those speakers? For as long as I have been messing around with hifi there has never seemed to be a speaker designer who talked to an amplifier designer. It's as though speaker designers have always thrown together designs that require enormous amounts of current to drive (1.5 Ohm Infinity's?!) and then amplifier designers rush to build stuff to drive such ridiculous loads. I use 82dB, 15 Ohm speakers so I'm not yelling about sensitivity (though 1% efficient speakers do seem ridiculous); but why buy speakers that require huge amounts of power to drive? Why not just buy a reasonable speaker that can be driven buy a few watts? When you put all those caps and inductors in a crossover, you do not get good sound. You get sound that has struggled its way through an amplifier's nightmare. Personally, I'm leaning more and more towards a few good tube watts and an efficient speaker to play without getting in the way of the music. . |
|
Silver Member Username: Mike3Wiley, Tx USA Post Number: 241 Registered: May-06 | After a long, long, long, day at the office I come home beat, dragged out, and in email overload. Then I find one of Jan's explanations and.... read it as many times as necessary so that I understand it. Education like this really shouldn't be bypassed. My take on this is that I was led by this forum to re-furbish my Carver M-4.0t, new caps, mods by Roland (see post above). I swapped that into my set up and never will look back. It drives my Anthony Gallo Ref. 3.1's as good as anything I can imagine. Not sure why, just sure that it is what it is. The Gallos love power and the re-furbished Carver delivers! |
|
Bronze Member Username: LeonskiPost Number: 12 Registered: Jan-07 | I see what you mean about amp designers and speaker designers not talking. I saw a pair of speakers today that Jan would LOVE. Yep, an old pair of Klipsh Corner Horns in perfect shape. I could just see a pair of vacuum tube monoblocs of about 10watts each and an attenuator/switch box instead of a pre-amp. About as close to 'A wire with gain' as you can get. I went out today to audition equipment to replace my aging, near death Carver Cube. I came home with a Rotel RB1070. While not as much juice as the old cube, I suspect better dynamics and headroom. I'll give it a few weeks to condition, than see if I can offend some neighbors. PS/ is this a Bipolar or FET amp? ...........thanks.......... |
|
Gold Member Username: NuckPost Number: 5680 Registered: Dec-04 | The 1070 will garner some attention, leo. I believe it is a FET array amp. my older Rotel was. Heavy, too. Friggin' cranks! The Classe cranks even harder, I still LOVE Rotel. |
|
Bronze Member Username: ChuckoyaHamilton, Ontario Canada Post Number: 33 Registered: Jul-06 | hey another question if you dont mind. if i was looking for one what would be a good price to pay (like good price, fair price, and just no way) and some questions to ask about it's condition? thanks chuck |
|
Bronze Member Username: LeonskiPost Number: 33 Registered: Jan-07 | Poor old cube! Now, should I get it fixed? Take it apart and see if there are some obvious problems.....burned board, bad soldier joints or whatever? Get some test speakers and some Cold Stuff in a can and spray the output devices? Could I use this amp in a Sub? 500watts should be about enough, and there are plenty of HomeBrew designs out there... I sure don't want to just dump this in a can! |
|
Bronze Member Username: StryvnPost Number: 39 Registered: Dec-06 | Leo, just curious, what's your take on the RB 1070? Got any angry neighbors yet? |
|
Bronze Member Username: LeonskiPost Number: 38 Registered: Jan-07 | The RB 1070 seems fine so far. It runs a little warmer than the old cube, but not to worry. I need to ventilate the enclosure, especially for this summer.....no A/C in house! As for sound, very good except when pushed. I think my speakers, 5ohm, near resistive (I'm told) should be an easy load, but don't forget, Rotel Doesn't publish the 4ohm spec for this Amp. However, they do publish a spec of about 330 watts at 8ohms for Bridged mode.....from which I infer output of about 165/channel at 4 !! (???) Overall, I am quite satisfied. I am NOT one of the golden eared persons who can say with some authority.......'damn mosquito in the room ruined the recording' or some such. I also have NEVER used the word 'palpable' in describing anything! That being said, the neighbors are fine, I have convinced them I am deaf and not to worry about the loud music! I will search later for a really good recording. I also think that my CD player, a multi-function unit is junk. I would prefer my now ancient, original Philips (magnavox in states) 16 bit top loader back in service. I made one other change at the same time.....I purchased 18ft of belden 10ga. and some expanding Banana plugs. After about an hour of assembly I have some super cables! I am wondering if my old cables were part of the problem? 12ga. lamp cord with wire that even stripped back a foot, still didn't look like the copper I know and love. The insulation was even getting a little....gooey as if being attacked by something. Best move was to just salvage off my Banana plugs and junk it out! More later, if I make any further discoveries. .................................................. |
|
Gold Member Username: NuckPost Number: 6071 Registered: Dec-04 | leo, that speaker cable was Harsh, man! |
|
Bronze Member Username: LeonskiPost Number: 39 Registered: Jan-07 | Yep, Nuck, Harsh it WAS. Now, do you think it could have at least contributed to the death of my cube? I want to use the cube (fixed, of course) as a Sub amp. Is this a non-starter? Plenty of oomph, but only 8ohms bridged is allowed. Maybe get a DVC sub and run each VC off its own amp? Feed 'em the same signal and there you go....the cube will handle 4ohms per channelso that may work. The link, above, to Carveraudiorepair will get a note from me later today. I just need to decide how much I'm willing to spend on the fix. If feasible, I'll DIY a sub. Like I need another Money-Sink hobby! not |
|
New member Username: PkmavenBoynton Beach, FL United States Post Number: 7 Registered: Mar-07 | Which Carver amp to buy: Sunfire. The Japanese have been pushing cheap to-produce "Mosfets" for years. They are immune to temperture fluxuation and, therefore ideal for mass produced receivers. All high end amplifiers use Bipolars because they SOUND better in amplifier output stages. Mosfets are often used in pre-driver stages. Bipolars produce a distortion which requires creative cicuitry to eliminate prior to output. This also includes car stereo amplifiers. P. |
|
New member Username: Lab350Post Number: 2 Registered: Apr-07 | Hi all, Anyone familiar with the Carver C1000a? Are the internal components similiar to the theater grand and newer receivers bob is manufacturing? Mike |
|
Bronze Member Username: PkmavenBoynton Beach, FL United States Post Number: 21 Registered: Mar-07 | To find out anything about Carver products visit www.carveraudio.com. It is an enthusiast website where one can find out almost anything about the products. Carver is not a Bob Carver company.It was sold years ago. Bob Carver's present company, Sunfire, is putting out innovative, higher end products. The current 1000A home theater amp as as good as an equal model Sony or Pioneer hta. |