Specs to look for when matching tube pre to SS amp


I would like to not make a costly mistake and learn how one determines (at least from a specifications standpoint) on how to match equipment. I have a deHavilland UltraVerve tube preamp and am looking for a new/used SS amp. The Dehavilland specs are:

Input signal: 2v RMS maximum
freq respon : 10Hz to 80kHz
noise : <80db
Max output : 8v RMS
Gain : up to 10db

The pre only uses single ended inputs and I want to match to a SS amp. My monitors are Focus Audio FS688 (85db) so I am looking at amps in the 200+ wpc range. Someone told me that I should go with an amp that has no more than @ 1.5 input sensitivity. Some of the amps that I'm looking at, GamuT and the Classe CA 2200 are in that range. I would like to consider an amp like the Blue Circle BC26MK2 as I have read it sounds somewhat like a tube amp and matches well with the Focus speakers, but it's input sensitivity rating is 4.48 to 200W. Would this create a mismatch? I believe the Pass Labs .2 series is also well over 1.5 . I do not often listen at loud volume levels. Is there more than amp input sensitivity to consider when matching to a tube preamp? I can not demo a lot of equipment, but would appreciate your suggestions. Thank you!
classical1
Input sensitivity is the input voltage required by the amp to output maximum voltage so it is related to the amp's gain. So, your preamp puts out 8V max - this means that the input sensitivity of your amp needs to be less than 8. You will of course find that basically all amps will be below 8 which means that the designers of your preamp aren't dupes. They made it so that it will work with any amp so you wouldn't have to ever worry about input sensitivity....

The output impedance of your preamp is the only spec you really need but you apparently don't have that number. I would ask deHavilland and see if they will tell you. In most cases, since the designers aren't dupes, you don't have to worry about this number either but with tube preamps, you should ask.

The rule of thumb of the amp's input impedance divided by the preamp's output impedance being 10 OR MORE is pretty good to assure that your bass doesn't get lopped off.

The cases where there are some technical mismatches are in fact quite rare (unless the designers are dupes). What happens far more frequently, IMO, is that the sound qualities don't match your desires. In this case, no numbers will help you, only luck and patience will. Good luck! Arthur
The output impedance of the DeHavilland UltraVerve is 600 ohms. They recommend amps that have a minimum of a 10kohm input impedance.

I am currently deciding between keeping a Plinius SA-102 (47kohm input impedance) or a McCormack DNA-500 (10kohm input impedance). I own both, and both are excellent matches with the UltraVerve. It's going to come down to my preferences, but these are two of the best SS amps that I have personally owned.
Well I remember when I bought a Goldman Memesis3 they told me not to use it with a CAT pre; because of the dc-off-set---whatever the hell that refers to. Anybody comprende dc-off-set??
Why do you think you need 200+ watts for small monitors?!
Even at the rated 85dB, this power level would reproduce dynamic peaks over 100 dB SPL in a normal listening position 10 feet away from the speakers.
I know some people claim you need 120 dB capability if you want to reproduce the sound in the middle of a brass band.
Better find good ear plugs if you do... :-)
Thank you! All of your responses have really helped. Serus, I don't know if I can answer your question, but my previous speakers were Dynaudio 1.3SEs (monitors), that I was driving with a Proceed BPA 125wpc amp. @ 5 months ago I bought a Proceed HPA2 which was 250wpc. The Dyns were 86db sensitivity and they had a much improved sound with the bigger amp- not only did everything seem to just 'open up' but highs and midrange sounded more refined. I don't know if that was a function of the increase in wattage or more current. My guess is a bit of both). I therefore have 'assumed' that an amp in the 200-250wpc range would be more compatible with the Focus Audio that are 1db lower. If this thinking is flawed plse let me know :) ..I also thought the Dyns sounded better at low volumes with the bigger amp. I sold the 125wpc amp before I bought the FA speakers, but they too sound nice at low volume levels with the larger amp.