2. amps-preamps
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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
paulfolbrecht OP
603 posts
 
Most passives do vary OI, you're right, with 10K being the top end. Into 180K, I think that'd still be fine.

I have tried a PLS on my system with the previous amps, which have only half the input impedance, and are less sensitive, and it seemed very good to me, including the dynamics.

Active preamps just seem like so much overkill when you've got a strong source and good impedance on both ends.
herman
2,222 posts
 
I agree with the responses about the passive. While your setup is certainly a great textbook match for a passive, some will still prefer an active stage. The good news is you can get a used passive and sell it at no loss if you don't like it. Personally, I've always like one with the right setup. There is usually a Placette or 2 for sale here and they retain their value very well. Give it a try.
unsound
7,318 posts
 
May I borrow this thread? Perhaps Herman can clear my head. I have a stereo amp that is rated at 250 watts per channel in to 8 Ohms with 26.6 db of gain. What is the amps sensitivty?
clio09
3,346 posts
 
On the other hand I have an amp with .8V sensitivity and puts out 225 watts (tested at closer to 300) onto 8 ohms. Can you calculate the gain. Thanks in advance.
paulfolbrecht OP
603 posts
 
Oh for pete's sake you guys! :-}
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