How to match preamp gain to amp sensitivity?


Can anyone tell me how to properly match the gain of a preamp to amplifier sensitivity. I read a bit about preamps having too much gain for an amp and I'm wondering how to go about NOT running into this problem or what the side effects of this is.
alun

Showing 4 responses by alun

Thanks again Rich, this could be a possible avenue for me.
I am thinking however that any pre that I use in my system may be only as good as the attenuators found at the back of my amp, and if these are NOT of the best quality, anything going to them may be just a waste.
I may look at them better and see if they can be bypassed or update with something like the EVS.
Thanks Racarlson, I see what you are saying. My amp (ARCD250mkII) actually has attenuators on the back of the amp. I've tried them out using my phono stage and CD direct and they work out pretty good but not enough fine tuning.
My reason for asking is that I'm looking for a preamp and on another post have had some good suggestions but I heard once that I could overload the input stage of my amp if I use a pre with too much gain.

When running direct into the amp it produced excellent sounds. Now I'm thinking that passive is the way to go. I could NOT open the attenuators wide open so I think my input sens. is very low therefore it could be a good match for passive.

Any suggestions on this?
That makes perfect sense Eldartford. I am using an Ayre K-5x that belongs to a friend which I soon have to replace as he wants it back. It's a very nice sounding unit with about 4db of single ended gain which works pretty good with my ARC amp. I wouldn't mind a touch more gain though as the Ayre is usually operating pretty high on the scale, but as you mentioned this is probably for the better.
That said would a gain on 10 or 12db be a LOT louder with less finess in the volume setting or would say 20db be a LOT louder. I'm not exactly sure how preamp gain affects the loudness of the final product coming from the speakers. I do know that a change of 6db in speaker sensitivity is like doubling amplifier power (so to speak) but I can't be sure if it's the same for preamps and amps.
Thanks
Hi Rich, I don't know if I've mentioned it but there are attenuators on the back of my ARC D250 and I am going to try it a bit more before deciding on pre or passive. I did it for a short period but no critical a-b ing. It did prove to me that the Ayre is pretty good but it will be going back to it's home in a week or two.
My CD and phono stage have plenty of gain and I can't open up the attenuators to max position at all so I'm going to assume that they have plenty of gain.
I just got my manual for the amp and it's input sens is .8v RMS for rated output of 240 watts! This makes me think passive will work really well. Input impedance is 75K ohms and I have read somewhere that this could matter a lot. I must do some more research however.
Thank you for your replies