Quicksilver audio silver 88 mono amps

I just bought a used pair of 88 monos and am blown away by the way they've transformed my system. Mike Sanders knows exactly what he's doing and offered up some great advice...just email him if needed. He'll respond quickly. They've added a whole new level of transparency and sophistication to the sound which I considered to already be good. Granted, I'm coming from a McCormick DNA 2.0 rev B, stepping down in juice from 600 to 80 watts and moving to tubes nonetheless, these babies are flat out fantastic! I replaced the JJ KT88s with Tung Sol KT120s and the difference was remarkable. The music became more life-like, with improved dynamics and bass by adding authority. I also replaced Electro Harmonix 12AX7 with Tung Sol and finally the GE 12BH7A with Sylvania (which had an unexpected massive impact). Now some or all of these tube replacements could have been because of age and since I bought the units used, I won't truly know. I give these monos extremely high marks for transparency, width of sound-stage, organic sound, imaging, precision of instrument placement, transient speed, mid-range lushness, harmonic depth and bass extension and control. If there is an average quality to these amps, I would rate depth of sound-stage to be just "adequate". It gets the job done here, but I think I expected a little more from tube monos...still not a complaint in any regard. The bass is what struck me most since I didn't expect this level of performance with reference to my previous "goliath" SS amp. In fact, the 88's outperform the McCormack even in this area and not just by a little, by far! Don't let anyone tell you that you need the watts to make deep, full bass sound extended and beautifully timed with bloom. The depth and control these mono's offer is the best I've heard and again... solid state over 30 years of audiophile listening. For the record, I'm running these with the Musical Fidelity NU Vista 3D CD, Audio Research LS25 MKII, Running Springs Duke and Haley, Auralic Vega, Wired for Sound modified Sonos Connect, Audio Physic Virgo 5s, DH Labs Red Wave Rhodium power cables, and all Audience AU24 SE and SX interconnect and speaker cables.