What's the best EL84 amp?

I’d be interested to know why a person would prefer the original RM-9 to the Mk.2 version. Dick Olsher (a favorite audio critic of mine) reviewed both, greatly preferring the Mk.2. Both reviews are available for reading in the Stereophile archives, I believe (I have a complete collection of the digest-size issues, my first subscription issue being that of Autumn 1971. It was J. Gordon Holt who changed my hi-fi life, not Harry Pearson ;-) .

In his Mk.2 versions of the RM-9, RM-10, and RM-200, Roger Modjeski successfully endeavored to lower the distortion and increase the linearity of the circuits of all three amps, resulting in improved sound quality. I know some listeners actually like the sound of high-distortion tube amps (Herb Reichert? ;-) , hence the popularity of single-ended designs in some circles.

Congratulations @dhcod! You are in a select group of lucky music lovers who have the pleasure of owning a Music Reference amplifier.

I actually had both version of the RM-9 (and got a chance to spend a day with Roger while he fixed one of them) and I think it's really about what you are pairing it with and what your ears like. Pretty sure with my current vintage bass reflex studio monitors, the Mk 1 would be better because these speakers are almost too clean sounding at time.

Still remember very well how hot those RM9s got. Toasty! But wonderful.

@dhcod: If you want to experience a hot amp, get a pair of mono Atma-Spheres. A pair of M-60's run 16 output tubes (in Class A), for a mere 60 watts//ch!

One day when we have some good A/C!

@bdp24 More people than one would have expected have told us they felt the RM-9 MkII sounded more like a solid state amp than a tube amp. It was certainly a lower distortion amp, with an upgraded power supply featuring added filter capacitance and chokes, but 8 x EL-34s for output tubes is 8 x EL-34s so go figure.