Class A amplifiers - which are considered the best
I have heard Accuphase makes the highest quality pure class A amplifiers. Wanted to get some feedback on folks experience with their amps and any other amp manufacturers that would be in their league (or better) for class a amps. thanks
If you like pure Class A solid state, these Mark Levinson ML2 monoblocks are it if you can find a pair, note the amount of heatsinks just for 25 watts of class A (no a/B) and they get HOT!!!. Goes to show that others are stretching a long bow when they quote class a figures with pitiful heatsinks and quotes of 100 watts of class A. What they're really saying is a small amount of class A up to a point then class b the rest of the way. Have a look at these beauties. http://www.wtconcept.com/levinsonml2/
Pass XA gets so much overwhelming love here I will give my +1 to Luxman. I replaced a Pass XA-30.5 with a Luxman M-600a and haven't looked back. Similar, but better all around for me. Like the sound, the build quality and craftsmanship is also more refined.
The amps run in AB mode but can be switched to Class A at the flick of a switch. Plinius claims this allows the amps to be powered ON all the time. You just flick it to A before listening. And after a period where there's no input signal, it switches back to AB.
For high powered Class A amps I would go with various Clayton models. If you have high efficiency speakers the Coincidence Technology Frankenstein 8 watt/channel Class A amps are impossible to beat. Played with a number of Coincidences own speakers (such as the Pure Reference, Pure Reference Extreme's, & the Total Victory V's), the sound produced is exquisite.
The best Class A amp or any amp for that matter is the one you like best. What I like in an amp most likely will be something different than what you like. You can take people suggestions but only you can tell what is the best. This is like asking what shade of blue is the best.
Mark Levinson 20.6 amps. Absolutely one of the best ever made and will blow away most of the amps made today. When going away from Mark Levinson the person, I guess the new company had to move forward with different (non Mark Levinson designs). But, what a great amp.
I also have Mark Levinson No20's bridged. They output 400W into 8 Ohms, 800 Watts into 4 Ohms or 1,250 Watts into 2 Ohms. At 2 Ohms that is continuous sine wave power. These to sound magnificent on Infinity IRS V's.
If you can find one in good condition...then I would say the original Krell KSA50. Hard to think of another Pure Class A amp that is significantly better than Dan's original design, just IMHO.
Mark Levinson ML-2 bridged, is a 100W class A amplifier into an 8 Ohms. I have used these amp to drive my Infinity IRS V's for 36years. The sound is magnificent.
Mark Levinson ML-2 bridged, is a 100W class A amplifier into an 8 Ohms. I have used these amp to drive my Infinity IRS V's for 36years. The sound is magnificent.
@Peterayer - thanks a lot for your comment. I was expecting much longer period of burn-in time ... I will see ...
@Audiofeil - I agree with your posts here in this topic. There is no simple formula how to pick up appropriate HiFi system or amp (in clas A or not).
Maybe it is worth mentioning that in Europe there is new regulation in preparation, which should limit the usage of units which work in class A. It seems that either class A in its design should be modernized (like Krell is doing it) or it will be simply forbidden, because of its waste of energy. The regulation is not yet agreed and not accepted in EU Parlament but the threath is there for classic class A designs ...
My XA160.5's took five days on 24/5. Music did not have to be playing through them. They became smoother, more nuanced and opened up to sound more effortless.
I'll add more fuel to the fire, beyond what Audiofeil said. Speaker matching is just one thing. Mine however lies in the power conditioner. If you read Audiogon messages long enough, they all sound about the same when comparing Class A amp. to something else. Needless to say, the differences between Class A amplifier designs would be less disparaging. Typical complaints about Class A amp. are too sweet and relaxed, and not enough treble.
The Audio Power power conditioner I use have 3 different electrical designs for outlets to be used with the sources (disc player & preamp). Other outlets are designed for amplifiers (by avoiding current limitation). If I set all source electrical inputs to the "balance" mode, it's an easy ride to listen for hours. The fine detail in the fabric of music is amazing as I described elsewhere. However plenty of warm up for all equipment (hours to days) must be there to reduce the softness, especially in the upper frequencies, to a barely noticeable level. The middle of the road is to switch preamp. electrical input to the "float" mode, which is in between "balance" and the unaltered signal, and the CD player power to unaltered signal. Now things are considerable more engaging. Vividness significantly increases. I can feel even more soulfulness and artistry of the performers-something that Class A amplifiers, regardless of power conditioner used, are known for. With more realism comes less distortion, allowing the soundstage to open even wider. Finally, if I switch everything to the unaltered electrical mode, it's just raw, very lively and forward. The music comes out of the speakers and brings me right into the soundstage. It's definitely the mode for your teenager children who want to boogie all night to the tune-very punchy from top to bottom frequencies. I unquestionable like the realism but there is only so long my brain can proverbially jump up and down with the music before it needs a physical break. Besides, the upper frequencies are getting a bit much, not as bad but begins to sound like my previous amplifier, which is actually rated by Stereophile as a class A (2 different kinds of "class A" obviously). The best way I could describe the difference between the last and middle mode is between live performance and studio recording where music is equalized and refined. I personally switch back and forth between the last 2 modes depending on my mood.
I own a pair of Pass XA60.5 and think the world of them.
Single-ended triode (SET) amps are best if you own efficient speakers. Art Audio, Wavelength and Larry Moore are superior quality. Avoid Chinese SETs, though.
>>04-04-10: Tzh21y I had the Aleph's "pure class A" at my house and then auditioned the Audio Research 100.2. It too wiped the floor with the Pass. Not all class A designs are better.<<
Totally agree; Class A alone doesn't necessarily make it the best choice.
An amplifier's performance is largely dependent on the speaker it's paired with. In your case the ARC matched the speaker and your ears better.
I'd venture an opinion there are speakers that might sound better to you with the Alephs.
I had the Aleph's "pure class A" at my house and then auditioned the Audio Research 100.2. It too wiped the floor with the Pass. Not all class A designs are better.
>>03-26-10: Faxer I compared the XA60.5 to the Luxman M600a. With the Pass you have to strain to hear the details compared to the Luxman. The Luxman after 200 hr break in will wipe the floor over the Pass. It is not as slow sounding it gets more 3 dimensional and is alot more natural sounding than the Pass.<<
Pure BS. I sell both lines.
This fellow obviously is quite inexperienced.
In fact, he sells Luxman but didn't make the disclosure.
I attended in Taipei, together with other muisc lovers, a comparison between the Accuphase A-60V and the Burmester 911 MK3. The German unit was sonicly much better that the Japan one. The Burmester 911 MK3 is more powerful and widely operated in Class-A. Instead the A-60V is a pure class-A. At my ears the Burmester was very much better in all parameters.
Clayton Audio, probably the best amps I've ever heard (I owned two of their models). If you can accomodate the heat, weight, cost and electrical draw, it doesn't get better than this (IMHO).
I compared the XA60.5 to the Luxman M600a. With the Pass you have to strain to hear the details compared to the Luxman. The Luxman after 200 hr break in will wipe the floor over the Pass. It is not as slow sounding it gets more 3 dimensional and is alot more natural sounding than the Pass. Remember Luxman gives fanatical attention to all it's internal parts. For example they do not use parts from other companies. Pass uses an outsourced transformer and transistors etc. On the contrary, Luxman does not it hand winds it's own custom transformers and uses it's own in house parts.
I have the Pass XA60.5 monos, absolutely love them, described them in enough messages on this board, thus won't bore you again.
As to electricity cost, letting them warm up for about 4 hours before using would get you 95% of their performance. The next level up would be 4 days, and that just does not seem worth the cost, needless to say being wasteful. But really, a 4-hour wait on the XA60.5 easily blows away most class A/B amplifiers out there. Now if you are in a rush, playing immediately after power on would already get you into the better end of class A/B amplifier selection. Nevertheless that's not the point when you purchase a class A amp.
I've always liked Nelson Pass's designs. He has been doing this for a long time. I have his latest XA30.5 and 100.5. They give me every indication they will last for decades. I have great respect for the Accuphase A50 also.
Another vote for Pass as well as Threshold;also these 2 but I don't know if pure class A might be worth checking out Jeff Roland older model amps and Boulder also.
The Krell cx series is Class A. I have a 300cx for about 6 years and it is a very musical amp in addition to provising the usual Krell tight and deep bass. Only downside, if there is one, is that it has only balanced inputs.
I really wonder about the V3 is not AB. This thing gets very hot unless in standby mode; even then it's warm. A call to Charles et all would be in order sir.
Bob bundus, you might want to do further background check as to which ones are really "class A" amp. I know Ayre amps are all class A/B amp. None of them are class A's. Ayre is one of the better design however. I would easily pick them over the majority of amp. out there. However you don't get class A sound in class A/B amp. unless you listen at extremely low volume.
"The best" is of course a subjective judgement. Synergy is ALWAYS the keyword: what matches up with your source component, speakers, cabling, + your sonic preferences? Experimentation is the only real way to determine that.
I can vouch personally for the Accuphase P450 being a fantastic product (although Mosfet; it's not a class A output) the driver stage itself is likely approaching class A bias; many other amps do likewise.
I also have an Ayre V3 which *is* 100 watts true class A, fullly balanced, another great design. I believe they also made a V5(?) with more output power + pure class A.
I do recall hearing some Krell class A monoblock designs at audio shows long ago; they're very large + very heavy. Spectral is another great one from years past.
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