I have used the Sumo Nine Class A amplifier consistently since 1982. This workhorse is everything I have ever wanted in an amp. It was designed by James Bongiorno, the designer of many great solid state designs beginning with the Dynaco Stereo 400, the SAE amp and preamp, and the GAS Ampzilla. Bongiorno says he's never had an output transistor fail in a Sumo Nine. I can vouch for that. I only had to replace one fuse in the mid 80s. How many people can say they've run a power amp for 22 years with this kind of reliability? And the sound is beyond criticism, in my opinion. The Nine is fast and very musical. It recovers from clipping very gracefully. I do not know the meaning of listener fatigue. I use the Sumo to drive DCM Time Windows, Dynaudio Audience 42s, and Tannoy Mercury M2s. I change the speakers from time to time, just for variety. Actually, the Tannoys run a distant third, but they also benefit greatly from the purity of the amp.

Any others out there who remember this great and greatly underrated amp?

yeah, the gas and sumo stuff is wonderful, but i try to not talk about it in open forums due to not wanting to drive up the prices! hah!!!!!!!!! hah.. until I get my full collection:).

love to hear the new ampzilla! with the vpms. oh.. my goodness. try some ribbons... nothing out there has both of best both worlds, detail and bass .. . can drive anytihng.

but for the high eff. speakers tubes still are in my den.
need more stuff!

Thanks for the reply. I bought this amp when I was earning decent money while making Connie Chung look smarter than she really is at KCBS-TV. When I worked there, there was a tech genius who recommended they install Bedini Class A amps in the editing rooms. Far better than what was actually needed in that dump. Sad story -- the Bedinis were eventually all THROWN AWAY by KCBS, when the editing rooms were renovated.