Quicksilver Mid Mono - power matching

spotconlon OP
Looking at a pair of QS Mid Mono tube amps

These are what Sam Tellig (Sterophile) has and loves (his favorite amp) and because they only need 1.2v input for full power output, they only needed my Lightspeed passive pre which he uses with them, as nearly all sources will have more than 1.2v output, cd is min 2v and even phono stages are over 1v

Cheers George

davidantonio!! Do you still have those amps for sale?

I love QS gear.....  Mikes new headphone amp is incredible....  all Quicksilver components are a huge bang for the buck

I'm no expert but I can list a couple things with confidence.

• I love the non-remote Line Stage and have seen it for $895 used, out there.
• Having a second out wired as decooney describes has been super helpful. My Line Stage is able to send to (a) my REL sub if I want and more importantly, (b) to another amp. Mike at QS made that mod for me for $50.
• I've heard from multiple people that non-remote is better. Since I stream a lot, there's a volume control on the streamer, anyway.
• I swapped tubes in the Line Stage and it pairs extremely well with a couple spare solid states I have in addition to my own QS Mono 60s.

I own the non remote linestage. If you need two outputs all you need is a y adapter. I use this when using a subwoofer. BTW, I have also owned the remote 6DJ8 linestage!
https://www.audioadvisor.com/prodinfo.asp?number=AQM22FHRD

@spotconlon
Nice, glad you got them, congrats!

The QS Linestage Pre is a bargain, fwiw. Add some nice vintage NOS tubes, done. Silver non-remote version is preferred by the sonic purists, remote version comes in Black only. If you use a RCA/out to a sub, you can send the Linestage to Mike at QS to convert TapeOuts to 2nd Pre/LineOuts. Ask @hilde45 here on Agon, he went this path with success.  

If there is any chance a local dealer will work with you to demo some speakers, it helps vs. online buy/try/ship back multiple pairs...

@decooney I bought them 😉 also picked up an Aphelion for the P6. Now for the pre, the speakers and the interconnects. 

Vandersteen and Quicksilver mate well.

@spotconlon 
Are you gonna snag those recent model mid monos listed on USAM? The newer ones with brass speaker terminals don’t show up that often, fwiw. People keep them for decades, usually.

Disregard. SOLD today.  Went fast. 

I have used them with Revel M106, plenty of power...PSB M2, a 4 Ohm speaker...drove them no sweat.  Current and favorite pairing?  Mid Monos with my Heresy III.  Great combo,  but the latter mentioned combos sounded excellent too.    

I am using KT 77 and they work well in the Mid Mono

@spotconlon
Are you gonna snag those recent model mid monos listed on USAM? The newer ones with brass speaker terminals don’t show up that often, fwiw. People keep them for decades, usually. 

I've used mid monos with Harbeths (85db) with KT88s and KT150s.They won't do rock concert levels but played pretty loudly without distorting in my med sized room.I'll echo what others have said,audition speakers you love.If you have shops to visit make an appointment and take the amps with you if you can't bring the speakers home to try.

I’ve used the QS Mid-Mono original 50 watt version with low sensitivity ( 83 DB ) LS3/5A type speakers with no problem at all. The room size was 20x15. I did prefer using the bigger brighter sounding KT88 tubes with the speakers that I was using!

@spotonlon
..I’ve heard sensitivity is an important concern and that I should be looking at speakers with 91db or more? Is that good advice? Do folks have thoughts, guidance on this?

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Capable lower watt tube amps, w/good transformers, paired with 4 or 8ohm speakers in the 85-89db sensitivity range can work at low to mid volume levels with moderate success (truly depends on the speaker design), a bit less dynamic/responsive maybe. Yes, QS Mid Monos are a lower noise design generally targeted more for use with higher efficiency 90db-100db range speakers as a general guideline. Higher efficiency speakers can help the amps to not have to work as hard staying above the aforementioned 91db, sure. Again a general guideline, results can vary per speaker.

I’ve heard a few different QS Mono amps paired with as low as 83db sensitivity 8ohm electrostatic speakers, and while it was surprising how musical it was at lower volumes, the same speakers woke up a bit more when I heard them with my own QS Mono 120s with more than 2x the power and much larger transformers.

A good buddy runs the QS Mid Monos with small lower grade 95db floor stander speakers and it fills up the house with sound fairly well. His prior tube amps had 2x the power, and he comments having to turn the volume up a it more with his Mid-Monos but loves how quiet and musical it is. The lower power Mid-Monos (50% triode) with good EL34 output tubes can sound quite musical when matched with quality speakers built with good crossovers/drivers. Treasure KT88s might be fun too, ask Mike Sanders at QS on latest tips and tricks if he’ll share. :)

Maybe share some speaker ideas you have in mind in your price range, and share over at the Klipsch forum too. You’ll find a few happy mid-mono owners there who’ll chime in periodically with their opinions too. Best of luck on the search.

OP, search a bit on this site, too. 
E.g. https://forum.audiogon.com/discussions/quicksilver-amp-owners

spotconlon - the Quicksilver Mid Monos are very good amps. They can work well with a wide variety of speakers. The operative term here *wide variety*. Speakers come in many shapes, styles, technologies and price points.

But it's hard to provide useful advice without more information from you, such as:
- your room and where the speakers will be placed?
- your seating distance from the speakers?
- what type of music do you listen to?
- what speakers have you heard that you really liked?
- What's your MAX budget? I'm not suggesting that you spend the max but it's useful for narrowing the scope
- new or used?

No doubt a lot of guys on Agon will chime in advising you to buy their favorite speakers. Do your homework and use your own ears (and preferable your own gear and room) to decide. It's challenging right now but it's still doable.

In general, I would probably agree with you that a ~40W PP amp will work best with speakers that are 90dB or better efficient. But like everything else there are exceptions and special circumstances.