SS amp with tight deep bass ?

I have the updated version. I'm actually on my second EE Minimax. To be honest, this little preamp is an overachiever.

Also, the Bel Canto "Ref" series and the S125 (but not the S/M 300) have an input impedance of 100k Ohm according to the Bel Canto website.

I have the updated version. I'm actually on my second EE Minimax. To be honest, this little preamp is an overachiever.

OK, good. The Bryston 3BSST that was suggested has an input impedance at its unbalanced inputs of 50K. The Plinius that was suggested has a 47K input impedance. Both of those numbers seem comfortable in relation to a 700 ohm nominal preamp output impedance.

Chances are a somewhat lower number would be acceptable too, but that can only be said with certainty if the 20Hz output impedance can be determined. If you can ascertain that number, multiply it by 10 to get a comfortable minimum amp input impedance.

The one thing that strikes me as being a possible concern with the Bryston is that it isn't rated to double power into 4 ohms, the ratings being 150W into 8 ohms and 250W into 4 ohms. That raises some concern that if the Classic's nominal 4 ohm output impedance dips significantly below 4 ohms in the bass or mid-bass regions (where a lot of power is required), and/or if the impedance phase angles are highly capacitive in those regions, the amp might run out of steam. Impedance curves that I've seen for some other Legacy speakers do exactly that. You might want to do some Googling to see if people have successfully used that or similar Bryston amps with that particular speaker.

The Plinius can double power, although its ratings are a bit lower (100W/200W), and that together with its 30A short-term output current rating seem consistent with being able to handle low impedances and difficult phase angles well.

Regards,
-- Al

Thanks Al. Geesh, You'd think the manufacturer would update their own website, as it is kind of important.

So with a single-ended connection the 3B-SST may do fine with many tube amps.

I was going off my experience of the 3B-SST with a balanced connection (10k Ohm per leg) to a BAT 3ix. The output impedance of the BAT is spec'ed at 1000 Ohm, but is actually much higher according to JA's measurements.

I also found the following statement in the marketing writeup for the PS Audio Trio amp (50k input impedance):

"No tube preamp should be asked to drive an input impedance of less than 30K"