Vacuum tube logic
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Biasing is not difficult, especially on amps such as the C-J which utilize a built-in metering system. If making this operation easy as possible is really an important criteria for you, you might decide to steer clear of amps that require the use of an outboard multimeter in order to set the bias, although this is not too much more of a hassle, and could eliminate some fine contenders. Also, an amp like the C-J, which allows separate biasing of each output tube, will not absolutely require that the output tubes be acquired in precisely matched sets only, which can make things easier and cheaper if you ever have to deal with one prematurely bad tube. For the lowest in maintainance of tube amps, you could narrow the field down to just those designs which feature auto-biasing, which never require any user bias adjustments be performed at all (there are designers who feel that fixed-biasing, where periodic adjustments will be necessary, has the potential to offer slightly better sonics, but there are also designers who successfully disagree and use auto-biasing on some very good amps). No other tubes on all-tube amplifiers besides the output tubes require such adjustments, so don't let the various smaller input and driver tubes scare you off - most stereo tube amps in the power range you are thinking of generally don't exceed 4 power tubes, so biasing them isn't an all-night affair. Also know that you probably won't have to rebias more than maybe once every 6 months or so.
(BTW, put simply and non-technically, setting the bias is how the correct operating parameters are maintained as intended for a particular circuit design and each output tube's type/brand/condition, because tubes, unlike transistors, will need periodic user replacement and will change as they age, and individual tubes always vary from one to another in their precise electrical characteristics. The actual adjustment of the bias current is most commonly done via labelled set-screws accessable through small holes in the chassis, in conjunction with built-in monitoring LED's or meters in the case of those amps not requiring the hook-up of a separately-bought outboard meter. The amp's instruction manual will guide you in the process and what the correct settings should read.)
As for what's out there, the answer is lots of stuff. I've owned the MV-60's predecessor, the MV-55, and it was a fine amp for the money, but there are many other brands competing in your range, including well-known marques like VTL and Audio Research. If I might ask, what is your system and room context, what do you listen to and how loudly, what is the solid-state amp you presently use, and what are you looking to gain by switching and why (or what inspired you to search in this direction)?
I highly recommend the Atma-sphere M-60 Mk2.2's (and so does T.A.S.)! Ralph's equipment is VERY stable, no output transformer (but you would want a speaker with around 8 ohm impedance or higher) and has the sweetness of tubes, with the bass punch of transistors. There are adjustments for bias, and DC off-set. On this amp, adjusting these settings is about as difficult as throwing the power switch on, and adjusting the volume knob on your pre-amp. Don't let these adjustments frighten you...they're real easy, only one for each set of tubes in the amp (some amps require 2 or more adjustments FOR EVERY TUBE!), and once set, they stay set for a long time!
The Bat amps are among the simplist to operate of all. The 4 main power tubes (the big ones) are on a auto bais circuit. Plug and play. a green led tells you everything is ok. The other tubes do not require adjustment.
About the only thing you'll need to do is if a tube goes bad, which happens about every 1 or 2 years for me, isolate it and replace it. By bad, you'll hear static, rushing water noise, popping, etc. Just slowly change (with powered OFF) tubes from one channel to anouther until the offending noise swaps channels. That's the bad tube.
This is one easy amp to operate. Don't miss out on one the best amps around.
The EAR 534 has no bias adjustments to make and is 50 wpc. Go to the website of EAR and check it out . It retails for 3595 and up. I do own one and have it for sale now for 1900 shipped to you in an ad on Audiogon. Mine has balanced and rca ins/outs and gain controls for each channel. It can be in a mono mode or stereo. I recently went SS in my amp areas because of ventilation problems in my new cabinet area after the move. I am by no means saying it is the only choice available but it made my Quad 989's sound extremely good.
Hi, As Jfrech said in his post the Bat tube amps couldn't be any easier to operate. The auto-bias feature does it all. Just plug in turn on and play and they don't need a long warm up time for them to sound their best. Also would like to add their costumer support is the top in the industry. Fantastic sounding also! Good luck, Tom
Zaikesman, I have a small listening room. My system consists of Decware preamp, two no-name 60wpc tube amps(low quality), Pioneer DVD player as transport, Bel Canto Dac, audioquest cables, and a pair of Silverline Panatella II speakers. I recently switched from B&W DM602s over to the Silverline speakers. My room is very small and it couldn't hanle large, full-range speakers, so I switched to the Panatellas which are basically floor stand and monitor, all in one, plus their frequency range goes much lower than the DM602 and they are very tube friendly speakers.
I listen to everything from rock to classical, but lately I have been more into classical than anything else. I have two pieces left to finish my modest system; a subwoofer(probably a Rel Strata III) and the amplifier. Audiogon has been a good ride so far.
After much trial and error I have found the right tube amp for me and it fits what you are looking for. Aronov LS960.
60 watts, auto biasing, and can use 6550, KT88's or KT90 tubes. Simply the best sounding I have heard. Kinda like a Jadis with bass. Other great tube amps worth a try are VAC and Musical Reference.
Matchstikman, it's interesting that you already own tube amps, given that you seemed to come across as if you were a tube novice, and I guess you should have a better idea of what it is you want than your question may have led me at first to assume. Well, since you say your current amps are "low-quality", then what you can expect with something better is primarily a superior power supply, output transformers, and passive parts/construction, although different circuit designs and execution will still sound different from one another. But in general, you can look foward to more tonal neutrality, frequency extension, dynamic capacity, and resolution/transparancy with a better tube amp, while still retaining the traditional tube-amp virtues of spatiality, harmonic purity, and lack of textural coarseness. Good luck with your search!
Don't know what your budgetary considerations might be, but my suggestion would be Mike Sanders' Quicksilver Triode. It is not on their website last time I looked (hope he gets it up there soon), but I know Mike is making them and selling them. I have two friends on the East coast who own these amps and cannot say enough good things about them. Like the BAT and the LAMM, they utilize the Russian 6C33C tubes and put out 65 watts in triode. I've owned three different pairs of Quicksilver amps and have loved every one for its own qualities. My current favorite amps are a pair of 300B SET's Mike made as prototypes, which I use in my home system with Klipsch La Scala's. His amps are all hand-wired and overbuilt like tanks. The Triodes are about $5.8K a pair. His V4 amps are KT88 based and are around $4K pair. The later can be found used ocassionaly. I doubt you will find the former on the used market..you would have to call Mike Sanders to inquire further about them. He sent me a picture of one. It appears to be on a similar chassis to the V4's. I posted the pic - you can see it here:
Glad to hear it Matchstikman. Once I heard it in my system I knew my search was over. They are nice people to deal with and will take the time to answer all your questions.
Last time I talked to Mr. Aronov, at least I think it was him, he was very kind and informative. At that time he beleived the Svetlana 6550 were the best all around tubes and didn't think you should waste money on more expensive tubes. Have heard some prople say they really like old KT88's though. Some interesteing comments at AudioReview on the amp as well. Think it still is rated a perfect 5 out of 5 there.
Happy Listening and good luck with your search
For true plug and play tube amps, I'll ante up with Audio Valve. Starting with the Avalons ($4500 for the pair of monoblocks), they include red and green LED's that tell you when a tube is going bad and needs to be changed. They are fully auto-biased, the tubes are easily accessible (by unscrewing 4 thumbscrews that hold the glass tops in place), and they sound great to boot. I have the ppp45's and I couldn't be happier with the sound or the maintenance-free life.