Rogue Atlas Magnum sounds bright -- any recommendations?


Gents, I need some help here.  I am making a move back to a tube amp, in place of my McCormack DNA .05.  I just acquired a early version of the Atlas Magnum with KT90's and it sounds excessively bright to my ears.  It has stock tubes.  I have a Don Sachs preamp driving my Spatial Audio M4 Triode Masters.  

I need to tame this brightness to better enjoy this amp.  Thanks for any input you can provide.   
whitestix

Showing 1 response by mulveling

I had Rogue Apollo monoblocks from 2010 that shipped with an all Electro-Harmonix tube complement - KT90, 12AX7 (gold pins), and 12AU7 (gold pins). That was indeed a very bright sounding complement. Almost ANY other tube choices you can make will be notably less bright; you don’t even necessarily have to go into NOS (though a few NOS tubes can be very bright, too). Start with Tung-Sol KT120 in place of the EL90. If you have Electro-Harmonix small tube, get rid of those too - e.g. maybe Mullard and/or Gold Lion reissues? I’ve also tried the Mullard EL34 reissues in a different amp, and liked those too. And a NOS short-plate Mullard 12AX7 will REALLY warm things up - in fact, too much IMO.