ATC SCM 40 v 2 and tube amplifiers

The db rating doesn’t really tell the whole story of how an amplifier is going to do with a given set of speakers. You need to look at the impedance curve of the speakers throughout the entire frequency spectrum crossed referenced with the phase angle, they combine to produce what is coined as equivalent peak dissipation resistance. A large factor is how a certain amplifier deal with fluctuation in EPDR in real time, how much voltage and current it can sustain through it all, and with what level of distortion.


Below is a Stereophile article that’s a good read on this subject.

https://www.stereophile.com/reference/707heavy/index.html

I use my ATC SCM40 v 2s with a Primaluna Dialogue Premium with KT120 tubes (also swap in KT88 and EL84 sometimes). In triode I doubt any bust past 35 watts but it works great in my setup. I do have a mediumish  to smallish room and never listen much past 90 dB so mileage may vary. To me the Primaluna just makes the ATCs a little rounder vs my Hegel H160 used during most of the weekdays. 

Yeah, you CAN drive the SCM 40s with tubes, but why?  They clearly need solid state power.  Does ATC build tube amps?  No!  You're better off getting something like a Pass, Clayton, ot Plinius Class-A amp and pairing it with a tubed preamp if you want tubes in your system.  IMHO. 

I agree modest powered tube amps will probably give a negative sound with the ATC SCM40's.  However the next best thing is to try a tube preamp with a solid power amp atleast reasonable power or even ATC own 150 power amp (P1).  ATCSCM40 speakers will show up the equipment used in the system.  So different preamp can have influence on the sound a little akin to like flavouring coffee with milk or cream.