I would also consider the Carvin TS-100. It is suppose to be very neutral and not color much.
Had one with my Axe Fx.... boat anchor.
The Return on my Blackstar HT-5 sounded better.
The Carvin is HEAVY!, and dead sounding in stock form. Good tubes and a bias mod might have woken that amp up, but I wasn't into wasting the bench time or money. It was 'flat' sounding, I'll give it that.
Much better choices out there.