Which 300b amplifier for Devore O/96

Myself and several enthusiast friends did a shoot out of sorts between a number of amps on a pair of O/96s. The preamp used was a CAT SL-1, a modest Rega TT with the CAT phono stage and a decent digital system with a transport through a Thor Audio DAC.

The amps used were: old Mastersound 32B integrated, Audio Note 300B parallel SET, VAC Phi 200 and Atma-sphere M-60s. The clear winner by a significant margin were the Atma-spheres. When bypassing the Mastersound's internal preamp with the CAT this amp came in second followed by the VAC. Last place was the Audio Note. There was a 100% consensus.

When compared with the M-60s all other amps sounded restricted and confused. This was especially true of the SETs. When you got above low volumes the SETs had a very obvious tendency towards homogenization of the presentation. Only with the M-60s did the sound truly leave the surface of the speakers and these were the only amps to offer a truly balanced presentation.

I cant stress enough the need for power with these speakers and also how these speakers love to be driven by OTLs. Even though many may disagree, I dont think that 300B SET power is enough to let these speakers truly breathe. 
 

I dont know Glen or Bill, but 10 minutes with either of these guys might result in a goldmine of information or it may result in ten minutes of competitive product bashing and only an attempt to sell you their products. I hope it is the former, but please be careful. 

I do know that in my conversations with John at DeVore he often shows with push pull designs which may or may not be entirely the result of sonics. With our group it seemed that we didnt know how much better the system could sound until we added more power and what I believe to be an inherently superior amplifier design (provided the speakers present a higher and stable impedance load). 

Seek advice first from those that have no dog in the fight.

 

Of the list you provide, I would only choose the Nagra if you like a less traditional tube sound. My experience with Air Tight is similar to the Nagra. I cant comment on the Wavac due to limited experience. The Shindo gear is great for a more traditional tube sound and what Luxman I have heard errs to the pleasant. 

But, in my experience, both push pull and SET designs are inherently somewhat flawed and in somewhat opposite ways. With the right speaker I have yet to encounter a better design than an OTL especially if you really want to hear what is going on with your software.

essrand

Well I am not surprised that you liked your 300Bs better than the Class D amps. Kind of an apples to oranges comparison. Take to heart what Ralph has said about how SETs sound when pushed. I truly believe that both P.P. and SETs are intrinsically inferior on the right speakers when compared with OTLs. Also, with respect, I couldnt disagree more with shkong78 reagrding his insistence on the influence that 300B tubes have on any SET design. In my experience the driver tubes have at least as much impact, somtimes more than the power tubes themselves. Tubes usually nudge, sometimes significantly, but they do not transform.