Quicksilver amps an appropriate match for Wilson Sophia?

"Very interested in the V4, the Silver 88 or even the mid-monos. Which do you think would sound best, and why?"

The V4's would be a great choice. I still regret not buying them.

Quicksilver build quality and more importantly sound quality is excellent for the money.

On a total impulse buy, not even looking for an amp I picked up a pair of Mid Monos back in November from a fellow A-Goner close by. They are GREAT amps for the money... When I got them they had 6L6c outputs and they sounded good but after a tube went I replaced them with the original spec EL34 and they sounded even better.

When my daughter graduates I am going to buy a pair of Silver 88's. But for now I'm perfectly content with these little guys, they sound better than any 40 watt amp has a right to.

I don't expect that the entire line of QS monoblocks are essentially the same, save for increasing power, correct?

What are the specific sound qualities that improve as power is increased (other than volume)?

I think I've ruled out the mid-monos. All things considered, I don't expect they'd be significantly different than the mini mites. For slight changes, I can simply engage in tube swapping with my mini-mites.

Can anyone make a comparison between the VTL ST150 and the QS V4?

Also, still hoping to hear from someone who has matched QS monoblocks with Wilson Sophia loudspeakers.

Allison2,
just expressing some thoughts here - I don't know if the QS amps are suited to the Wilson speakers or not. I've not seen this pairing often but it does not mean that it won't work.

In power amps, the bass heft is, I believe, directly proportional to the size of the output transformer. The bigger, the better it is for bass reproduction. You see humungous output transformers on Audio Note Japan & CAT power amps. I don't think that is just for show or to make the owner's life difficult hauling those amps around; i think it is done deliberately for better/best bass reproduction. The QS amps just don't seem to have large output power transformers & simply based on this I get the feeling that their bass is going to be on the light side for a Wilson speaker.
At the 2013 RMAF i attended, Dave Wilson showed off his Alexandria speakers driven by VTL Siegfrieds (yeah, these are probably in the "unobtainium" region) & the sound was very good.
Looking at the VTL amp specs, it seems that, weight-wise, they are at least 1lb per 1W & it "appears" that this weight is in the output power transformers (I cannot confirm this). This seems to be better for bass frequencies.
Maybe it's better to save up some money & buy a better VTL amp such as a S-200 in, say, used condition?
Like I wrote at the start - just some thoughts based on my experience of listening to tube amps at shows & at my friends' place & at dealer show-rooms & the info gained by talking to some tube amp designers. Take it at face-value. Thanks.

02-11-15: Allison2
Wilson Audio Specialties Sophia loudspeaker Specifications
Description: Three-way, floorstanding, reflex-loaded loudspeaker. Drive-units: 1" (25mm) inverted titanium-dome tweeter, 7" (178mm) paper-cone midrange unit, 10" (254mm) aluminum-cone woofer. Frequency response: 29Hz-22.5kHz, +0/-3dB. Sensitivity: 89dB/2.83V/m. Impedance: 4 ohms nominal, 3 ohms minimum. Recommended power: >12Wpc.

I'm sorry but I don't consider the Wilson Sophia to be a sensitive speaker. I'd call it a medium-low sensitivity speaker.

Also note that the spec says "89dB/2.83V/m. Impedance: 4 Ohms". Usually, the industry "standard" is to measure the speaker sensitivity using 1W into 8 Ohms at 1m away.
If the speaker is 8 Ohms, the RMS voltage works out to be 2.83V & one is feeding the speaker 1W.
If the speaker is 4 Ohms & one still uses 2.83V, then one is feeding the speaker 2W (not 1W). So, the Wilson Sophia has an artificially elevated sensitivity simply because it's being measured using 2W of input power (not 1W).
So, subtract 3dB from the Wilson Sophia sensitivity - that makes it an 86dB/1W/1m speaker.
Hence my saying it's a medium-low sensitivity speaker.

When you are sitting, say, 10ft from the speaker, the SPL at your listening chair will be 10dB lower due to volume drop-off by the square of the distance of speaker & you + some absorption of sound by the room, furniture, carpet, walls, etc.
So, you're really going to be hearing 76dB SPL for 1W fed (by your amp) into the speaker.
You say you don't listen very loudly - that's a bit nebulous if you don't give a SPL number. Let's ASSUME that you don't allow the average SPL to get any higher than 86dB at your listening chair. That means you would need 5W/ch - this would give you an 83dB SPL at your chair + 3dB due to stereo/using 2 speaker for a total of 86dB SPL.
Then you should allow another 10dB for dynamics - sudden elevations of SPL due the program material. So, you'll have peaks hitting 96dB SPL. Or, 20dB higher than the 76dB SPL you were getting with 1W into the speaker. 20dB in power is a factor of 100. So, you'd need a 100W/ch amp to ensure good dynamics when you limit your average SPL to 86dB.
In reality a lot of music would feel restrained if the SPL was limited to just 96dB for the peaks. Classical music is just one genre. There are many genres where peaks hit a much higher SPL if allowed by the amp & allowing these peaks adds to your overall music listening pleasure. So, requiring a 150W/ch or a 200W/ch is very much within the norm.
You can see if you want free-flowing music i.e. music that does not sound restrained, you need quite a lot of wattage very quickly. Something many people do not keep in mind.....
Needless to say, unfortunately, the amp cost goes up exponentially....