Quicksilver audio silver 88 mono amps

I'm considering buying a set of these from the music room in Erie, Colorado.  Does anyone have experience with this amplifier.  My McIntosh MC75's need some work and I'm going to have them refurbished to factory specifications.  I want something in the meantime to use in my system.  Thanks for your input.

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.
"I replaced the JJ KT88s with Tung Sol KT120s and the difference was remarkable."

If you can recall, did you find the stock JJ KT88 output tubes to sound kinda lean and edgy and less musical in your QS KT88 Monos?

Asking for a friend who’s not yet researched replacing them with something like Genelex Gold Lyon KT77s or GL KT88s, or PSVANE CV-181-Ts, or Shuguang Black Treasure tubes. Thinking this might help... wondering if you tried any of these with your Mono 88s in addition to your current Tung Sol KT120s.

@ gochurchgo: I will receive a pair of new Quicksilver 60 Watt monoblocks next week.  I intend to pair it with a Thor TA-1000 preamp with significant upgrades including about a dozen Vcaps.  The other preamp I have is nearly as good, but it's homemade, unfused and based on subminiature tubes so I don't know how helpful that is.  Come to think of it, the Thor is completely obscure, too - but interesting!  :o)

After reading for a couple of hours, I have ordered a matched quad of Psvane Black Treasure KT88-T Mark II to try as an initial upgrade to the stock Chinese tubes.  Other contenders may include the Tube Store Preferred Series ($280 per quad) or Sophia Electric KT88-ST (blue coke bottle, BUT starting at $500 per quad!).  JJ KT88 are also available for about $175/quad but I'm not sure they are at the same level; Merlin VSM speakers will reveal as much detail as they can get.  The VERY low end is handled by a JL Audio Fathom sub.

Any suggestions on the best KT88 to run in a straightforward pentode amp running some very neutral and musical sounding Merlin VSM floorstanding monitors?  Very slight tendency to brightness, with the wrong things upstream, but mostly to honesty (no gripes after 13 years with the same speakers!).
Hi @augwest  I have the Quicksilver 60 Watt monoblocks and to deal with some brightness, and on the suggestion of @decooney (here), I went with the Genelex Gold Lyon KT77s. I've been happy with them. At this point, I'm pretty sure that my low ceiling is the main cause of the brightness (I've put nice tubes in other sockets, too, so it's not them), but my sense was the the 77s helped. FWIW, I have a QS Line Stage preamp with good NOS tubes in it, too, and an R2R DAC.
The QS mono tube amps paired with your recapped Thor tube preamp should be fun. Appears VCap was a common upgrade in your preamp, photo here, and nice wide and thick copper strips on the main board, cool.  :) https://www.audioasylumtrader.com/images/y2013/12/100421/FullBoard.jpg

IF it’s a new set of QS monos, give them and internal caps time to burn in with stock tubes or the PSVANE if you get them soon enough. The PSVane BT Mark Its should sound pretty smooth, just helped a friend put them in an integrated amp. After the input tubes burn in on the QS amps, (if new stock tubes) you may want to update those and store the stock ones away. Also, kinda depends on your preamp and tubes too and how bright or smooth they are. It’s a basic balancing act on both ends. Is that brand new or used (burned-in) monos and what input/signal and output tubes are in them now?