Preamp gain vs. poweramp sensitivity


Hello,

Just purchased an Art Audio Carissa which has input sens. of 600mV (very high). At first, I was thinking that I would want a high-gain pre because the Carissa puts out only 16W/ch and could benefit from some preamp gain.

However, I believe upon considering the sensitivity that a high-gain pre is NOT desired because:

1) I would need to open the VC only a bit before the Carissa was driven to full power.

2) For the above reason, the high-gain is wasted anyway because the pre wouldn't be able to put out what it's capable of without overdriving the Carissa.

Do I have this straight? The relation of gain to voltage is not clear to me. The preamp is specified as outputting 2V yet, with a standard 2V source, that is actually unity gain! So what exactly does "20db of gain" in a preamp mean?

Thanks for clarification on this question.

Paul
paulfolbrecht
I don't mind the bogarting of the thread. It's all good. I haven't run your #s but if you used Herman's equation it must be right.
250 watts per channel in to 8 Ohms with 26.6 db of gain.

26.6 dB..... 10 to the power of (26.6/20) = gain of 21.4

250W into 8 ohms takes 44.7V because ((44.7 squared)/8) = 250

44.7V divided by 21.4 = sensitivity of about 2.1V

.8V sensitivity and puts out 225 watts (tested at closer to 300) onto 8 ohms.

300 watts into ohms takes 49V

49V divided by .8V = gain of 61

20 log 61 = 35.7 dB
Clio, I think I did yours incorrectly. It may be capable of 300W, but if the rating is 225W with a .8V input, to get 300W would take an input voltage higher than .8V.

To get 225W into 8 ohms takes 42.4V

42.4 divided by .8 = a gain of 53

20 log 53 = 34.4 dB