Tvad's comments match my experience with other triode/ultrlinear switchable amps. Love 'em in triode for chamber and small ensemble jazz for the harmonic "rightness", nuance and delicacy they deliver. Switch to ultralinear for large scale orchestral or rock for the added power and bass control (and just wish they could better deliver that triode magic of mid-range clarity and accuracy of timbre). My experience was with the original Marantz 9 amps, after which C-J then modeled their triode/ultralinear designs. Great work by Bill Thalmann introcing this at C-J.
.
.