What is Moving From Solid State to Quicksilver Mid Monos Like?

Fastcat95,

In a huge coincidence, I am the third person in this thread to also move from a DNA-125 to Mid Monos. I also used Frieds (A3s) with my Mid Monos as well as Spendor 1/2s, and sadly these amps (paired with the QS linestage and using really nice EL34s) were just too lean for me in the bass and mids compared to the DNA-125. They were also a bit grainy in the highs in my set-up. I solved that problem by eventually moving to the Mono 120s, which I still use now using KT120s and Gold Lion small tubes. I also own KT Monos using Mike's stock KT-88s (Chinese) with RCA NOS 12AX7s and EH12BH7s...absolutely superb amps that are far better than the Mid Monos, imo, in every area. Looking back, maybe I should have tried some KT88s in my Mid Monos to fatten them up some. If you want to jump to Quicksilvers, I suggest starting with KT88s or KT120s if the power transformers are up to it. If too lean, you can easily sell them and then grab a pair of KT Monos or Mono 120s, which kick the DNA-125's butt up and down the street! 

Interesting @bojack how you are using the small input/driver Gold Lyons. I pulled my vintage 1960s Mullards [had PSVanes] prior, out of my Quicksilver Mono 120s and decided to order and install the small GL (12au7, 12at7s) a few weeks back. So far so good. I suspect a bit more time is needed on the small GL tubes.

I did this [trying the little GLs] to try and bring out more of midrange body the prior-prior PSVane had, and yet not lose too much of the detail the vintage 60s Blackburn plant Mullards have. The GLs seem to sit right in the middle of the prior two pairs so far in the QS M120s.   When the Mono 120 transformers are fully warm, it opens up a little more. I’m testing more this weekend with the new little GLs. Opt Bias is a kept bit low on the amps now. I will go ahead and turn the bias back up 10ma more on the main KT120 output tubes to see what happens - now with small GL tubes in.

For those same reasons you mention, I encouraged member @hilde45 to jump up to the QS Mono 60s a few years back. This was before the new version multi-purpose QS KT Monos came out.. Hilde45 has been able to try different speakers as a results, and his amps nicely run KT77s today IIRC, although I believe he’s also tried KT88s, KT150s, KT120s with different efficiency and types of speakers now too. I was in town and heard his setup with KT77s before. With those amps, the KT77s sit nicely between EL34s and KT88s as I recall it sounding. I can see why Mike Sanders decided to develop the new KT Monos even more so now fwiw.

@fastcat95 "...(.75" tweeter, and dual V.C. 6.5" bass mids). 89 dB sensitivity; impedance probably drops to 4-6 ohms" "...what do you think???"

My friend has a similar speaker configuration and spec, slightly more sensitive than yours, similar impedance - running with his QS Mid-Monos. His former high power amp w/EL34s drove his speakers a little better, more bottom end. It’s fine for low volume, but when he needs to turn it up a little more - having the separate/extra subwoofer helps quite a bit. As noted before, he is back to looking for more efficient speakers in order to keep the Mid Mono amps instead.

If you truly want a more comparable step-up move with tubes coming from your DNA 125, keeping your existing speakers, I’d say skip the lovely lower power QS Mid-Monos and go with the newer KT Monos -or- one of the prior generation amps in the 60-90w range. For ref - several prior products are listed here to keep an eye out for used market fwiw. Others here might chime in too. I think at least the former Mono 60s or Mono 80s would do the trick I’d bet. They pop up 2nd hand periodically https://quicksilveraudio.com/past-products/

Hi Fastcat,

My DNA-125 was all stock, and yes, I agree that that amp in stock or modded form is an all around better option that Mid Monos. Though I did not have that amp for long, I did enjoy it, but the higher power QSs sound more like music to my ears. Btw, the Mid Monos have had 2-3 different iterations:

V1: Beefy output transformer, small power transformer, and one bias adjust pot.

V2: Two small transformers and one bias adjust pot.

V3: Beefy power transformer, small output transformer, and 2 bias adjust pots (this is his latest version I believe).

V3 allows for better bias matching and tube life, which is ideal imo.