Compatibility between preamp and amps

Lol SMH

With digital sources that output at higher voltages than most analog ones the 11 dB gain in the pre may be beneficial. You have 41dB of gain total which should  be fine. One thing I question is the amps sensitivity. At 0.85 volts, it is very sensitive if that is all it takes to drive the amp to full power. The sensitivity of the speakers also come into play. 

@mesch I do believe that the 0.85v may be a potential issue. My speakers are about 92db efficient. I get noise (hiss) from my system and I think it is incompatibility between the 2 pieces. each on their own with other components they are fine.

Yea, a 0.85V sensitivity 30dB amplifier is a candidate for a passive pre. Not to say that I prefer that route. I am currently using a active tube line stage preamp that has variable gain output with a SS amplifier. My take is that many digital based systems have too much gain that is then attenuated. Therefore a low gain preamp with a low sensitivity (high V = low sensitivity) amplifier can be beneficial.

thanks but isnt there more to it than impedance ratios? like gain and sensitivity?

@jimbones Yes.

For starters, the output impedance at 20Hz is probably where you should look. With many preamps, the output impedance rises at lower frequencies.


The gain is another matter- much depends on the gain of your amps and the sensitivity of your speakers. As a general rule of thumb, more powerful amps tend to also have more gain as they are used with less sensitive speakers. This should make the gain of the preamp a non-issue, but since the advent of Redbook (which set a standard of 2 volts output for single-ended digital sources) the amount of gain in the preamp has been a bit trickier to sort out. In general though, a reasonable amount of line stage gain is about 15dB. If you are only running digital though, a reasonable amount is about 6-10dB.