Compatibility between preamp and amps

@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.

Had a huge worry myself, while u sing a Sanders “the preamp” with a McCormack mono pair. Volume would not start until I hit almost 40 or 50 on my vol knob.
   Turns out, it’s made that way, same with my McCormack preamp.

I’m fine now.

Yes, the gain provided by a preamp is one thing, and often more than needed. How the gain is distributed via the volume control is another.