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

I went from a DNA 125 to a pair of Quicksilver Mid Monos.  The McCormack was a great amp , it was my first solid state in years.  Prior to that I had several decent tube amps.  

I have used the Mid monos with PSB Platinum M2 , Revel 106, Heresy, Forte, Sonus Faber Concerto  and a few others.  

Mine were built in 13, I bought them when they were 1.5 years old.   They have seen continuous duty up until fall of 22 when I bought a 300b.  I'll rotate my amps occasionally,  

I have them in my system now and they sound great with fresh EL34.  I also have late 50s RCA 12ax7 input  and JJ 6922 drivers in them 

They can use almost any el34 and 6l6 variant.   KT88, 77,66,    and others.   Can "sound" how ever you like.   

Hard to beat new for the  money  , steal used.     

I'll second what oddiofyl has written and add that the mid-mono soundstage is awesome. You get space/placement between instruments, mid-range second to none for the money, and a wonderful EL34 liquid tone. Finally-they are well-built.

@fastcat95 ..." Can anyone out there who has made a move from good SS equipment

to the mid monos tell me what they gained that made them happier with the sound?"...

Some of what you might "gain" or even "miss" may also have a direct dependency on your speakers impedance, efficiency, and the size of the room too.

+1 to what @oddiofyl stated. If you can swing it, plan to keep both for a while and rotate back and forth. You’ll end up appreciating both for different reasons.

While I have the larger QS monos running KT120s now, and not EL34s, and also still alternate with 50w Class A SS amplification [formerly 200wpc SS] - both have their +/-. I suspect the "midrange" is what you’ll probably like most about the QS Mid Monos. I helped a friend into getting a pair of mid monos after he heard my other EL34 amps of the past. He talks about getting more efficient speakers now from time to time, but it’s not totally necessary. His prior amp was EL34 tube based and 2x the power of the mid monos. The mid monos came into the picture for more reliability. He now has a large subwoofer to go along with his QS Mid Monos. Fills the room now with more low-end reinforcement. It is  a larger than average room with really high ceilings.

Imo, the top end and lower end bass drive will still be there if your speakers are more on the efficient side. I’m keeping in mind you are coming from a DNA 125. When I use to flip back to my former/larger SS amp with more power [like your DNA 125], there was this added sound pressure that filled the room a tad more in a larger room with less efficient speakers. Again, the room and speakers matter here too. This is what might also be considered about what you might "gain" or "miss" or be happy with. Try both, keep both, and rotate. Best of luck.

+! @decooney  I would also add the obvious, that the outcome of any SS vs. tube amp comparison will be dependent on the speaker used. 

@fastcat95 What are the speakers under use?

Hey guys!  Thanks for all the input!

My speakers are a pair of vintage Fried C6/L 2-way monitors (.75" tweeter, and dual V.C. 6.5" bass mids).  89 dB sensitivity; impedance probably drops to 4-6 ohms in some parts of the bass-mid range (to 2.7 KHz crossover); small to mid size room, and I do not play very loud (90-93 dB peaks at listening position - 2 meters).

What do you think???

I have owned those QS Mid Monos and used them with 83 db sensitive speakers with no problem. Those amps are a true value. I have never enjoyed solid state since. I am a QS fanboy and Mike Sanders makes gear that is built to last!!

@yogiboy which 83db speakers were you using with Mid-Monos?  Are they 4 or 8ohm?

At my 55year-in-business local dealer who sells AudioNote and Quicksilver, I've also heard low power 10w amps playing 83db speakers there which are 8-ohm. Sure the amps power the speakers to play sound, yet the dynamics, volume level and room filing sound capability was a bit constrained. 

@decooney I have used them with LS3/5a type speakers including Spendor, Harbeth, etc. BTW, all 8 ohm!

Good to know @yogiboy and thanks for responding.  I'm thinking most of Mike's QS amps seem to respond and sound, dare I say, more musical with higher impedance speakers, 8ohm and above.  

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! 

@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.

I have a pair of QS Mid-Monos, the latest version with the 2 bias pots, with EL34, that I regularly rotate in my system. Currently they drive a pair of Harbeth 40.3 XD. I use new Tung-Sol tubes with which I replaced the tubes that they came with the units. The other tubes are those who came with the amps. I bought the Mid-Monos used.

The QS have no problems driving the Harbeth in my medium sized room.

Here’s how I would describe the sound with the Harbeth in my room.

There is plenty of resolution, tonality, and warmth. Not much punch in terms of dynamics but an addictive and intoxicating mid-range. Bass is fine but a little loose. Overall, the Mid-Monos are excellent amps, a great deal, even a greater deal if found used, I think I paid around $1300 for mine, made in USA, and Mike Sanders is an email or a phono call away to answer your questions. I got a response to a question that I had in an email in less than a day.

There is nothing better imo to be able to communicate and get support from the designer himself.

I did just the opposite (e.g. went from quicksilver monos to SS) and have never looked back.  Besides the constant repairs needed for the “quickie’s”, the sound from my McIntosh / Threshold / Ayre amps were superior in comparison.  While I would consider a tube line stage again, I would never again consider having  a tube amplifier.  That said, from what I hear, current tube amps are much more stable.  

People talk about repairs on tubes...I have owned tube amps for 40 years and never had to repair one. WTH? 

If you run the tubes the amps and circuit was designed to run with day-1, and you keep an eye on the bias, turn them off/on properly in sequence - some people will argue good tube amp(s) will last longer, and can be lower cost to repair - if they ever need repairs.  Particularly when there are no aging and cracking circuit boards inside. While I own and use both, replacement parts are easier to find for my tube amps than my Class A solid state amps as learned over time. Choose well!