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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
unsound
7,329 posts
 
Herman, thank you very much!
clio09
3,355 posts
 
Thanks Herman, this helps quite a bit.
herman
2,253 posts
 
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
clio09
3,355 posts
 
Thanks for the update Herman. I suspected the gain was very high, just didn't think it was over 30db.
phillyb's avatar
phillyb
401 posts
 

What I can say about gain is the improvement it can make to your system. I have an ML amp and 326S preamp, and I can set the preamp to o gain, 6db, 12db, and 18db. Each step up from zero improves the sound, I like the 12db, but I recently tried the 18Db, and what I have experienced is a more relaxed sound, more open, more dynamics in the bottom end, and just a more pleasant and natural sound without any downsides. 12Bd sounds more sharper and detailed but not as natural as the 18db, So gain does make a sonic impact which is why buying a new preamp with more gain than you had before will sound different for sure and most likely better. My vocals are now in the room with body and openness. I guess much less like a recording. 

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