Rebbi, I think it is worth revisiting one very important remark in this long(ish) thread:
"10-07-14: Charles1dad
Hi Seikosha,
The limiting factors are the quality of your transformers and the stiffness of the power supply section."
Why is this important? Because - I believe - that a lot of times when people talk about an amp "running out of power" it is more a function of the power supply's ability to store/deliver power to the output tube than the amp's stated wpc. This is especially true in SET amps.
That's why we find that one 8wpc 300B SET amp can drive a specific set of speakers louder without stress than others. The transformers also play a big part in why one amp may seem to "dig deeper" or have better bass than another amp rated at exactly the same wpc.
Let me recommend Art Audio amps - across the board, this company is famous for building SET amps that drive speakers far beyond what their ratings suggest. The company prides itself on building each with an incredibly robust power supply. I've personally owned their PX-25(6 wpc) and Jota (300B/ 20 wpc).. Look up the reviews of these amps, they are some of the best...and expensive. (though, there is a used PX-25 here on A'Gon for $2.5k - a steal)
The 6 wpc PX-25 is one of the finest SET amps I have ever heard. It is truly a "reference" level component. One pro reviewer summed it up best by say saying notes sound "as if they were lit from within". It played with delicacy and power. Richness and purity. And for giggles. I even ran my 89dB/4 ohm(not a good match for SET) Jean Marie Reynaud Twins mkII moniors with it fairly often. It really didn't have much trouble at low to moderate levels. Not a lot of bass, but the mids and highs were pretty damned good at low levels.
The Jota(KR 300BXLS or AV 320B SL tubes) and especially the high-current version at 24wpc (KR VV32B tubes) will likely do really well with your speakers. Check out the professional reviews of these amps, they kick ass.
