Decrease power amp’s gain to increase resolution of preamp?

[agencal]

Hi
I heard from PS Audio videos that at low volumes pre amps loose some resolution. When you increase volume they open up. I am living in an apartment and mostly listen in low volume levels. I hava a CH L1 pre and M1.1 power set up. The power amp allows to reduce gain uo to -12db. If i do that now i can increase the volume of pre amp all the way up. Am i increasing resolution in low listening levels by this or improve distortion?

 

[Mike Lavigne]

Hi
I heard from PS Audio videos that at low volumes pre amps loose some resolution. When you increase volume they open up. I am living in an apartment and mostly listen in low volume levels. I hava a CH L1 pre and M1.1 power set up. The power amp allows to reduce gain uo to -12db. If i do that now i can increase the volume of pre amp all the way up. Am i increasing resolution in low listening levels by this or improve distortion?

mostly we are talking about a couple of things with preamp volume and amplifier gain.

1--preamp volume attenuation. many volume pots have sweet spots, the best do not. in theory unity gain (zero attenuation) is ideal. so that is a variable. does your CH pre have a sweet spot? then noise is an issue and where is noise an issue? then dynamics and where are dynamics the best for musical flow? the best preamps stay optimal through the normal volume range. but some don't.

2--amplifier gain. when it's adjustable this is very speaker dependent. for instance if you have a 95db efficient speaker maximum gain setting in your amplifier will likely sound best, as the noise at the higher gain is less an influence than the benefit of having more power. OTOH if you have a 110db efficient speaker then maybe lowering the amp gain will lower noise since you might never have occasion to need that extra gain.

in your apartment where you are SPL restricted, likely you want the lowest gain in both pre and amps since you will never need the fully opened up status, so lowering noise is the priority. but then this has to be balanced by whether the music comes alive or not with the lower gain. just have to try all the alternatives and see how it sounds. resolution is certainly important, but that comes with finding the right volume level for each recording to come alive. there are lots of factors such as the efficiency of your speakers, and the quality of the first watt of your amplifiers, even acoustics and ambient background noise level. hard to generalize.

 

[agencal]

mostly we are talking about a couple of things with preamp volume and amplifier gain.

1--preamp volume attenuation. many volume pots have sweet spots, the best do not. in theory unity gain (zero attenuation) is ideal. so that is a variable. then noise is an issue and where is noise an issue? then dynamics and where are dynamics the best for musical flow? the best preamps stay optimal through the normal volume range. but some don't.

2--amplifier gain. when it's adjustable this is very speaker dependent. for instance if you have a 95db efficient speaker maximum gain setting in your amplifier will likely sound best, as the noise at the higher gain is less an influence than the benefit of having more power. OTOH if you have a 110db efficient speaker then maybe lowering the amp gain will lower noise since you might never have occasion to need that extra gain.

in your apartment where you are SPL restricted, likely you want the lowest gain in both pre and amps since you will never need the fully opened up status, so lowering noise is the priority. but then this has to be balanced by whether the music comes alive or not with the lower gain. just have to try all the alternatives and see how it sounds. resolution is certainly important, but that comes with finding the right volume level for each recording to come alive. there are lots of factors such as the efficiency of your speakers, and the quality of the first watt of your amplifiers, even acoustics and ambient background noise level. hard to generalize.

Thank you. Than if i understood rigt i can give it a try. It will not increase distortion or noise up to some leveş.
My speakers are 92db il cremonese ex3me.
Maybe i can ask yo CH Precision team for the sweet spot of their pre amp volume level.

 

[Amir]

you should ask this question from CH Precision company.

If power amplifier gain is related to negative feedback then I think higher negative feedback is not good.
As you know higher negative feedback reduce both gain and noise.

 

[Audiohertz2]

All gain controls have sweet spots , as well as drive voltage to load sweet spots , having adjustable gains allow you to set the sweet spot for best performance..

 

[Salectric]

As @Amir said, it is important to know how the amplifier gain is adjusted; it’s also important to know how the volume attenuation is accomplished. If the volume is changed not with a pot but rather a digital chip, there may not be a sweet spot.

Power amps these days rarely have audible residual noise but some preamps do. In that case, lowering the amplifier gain can reduce the preamp noise. However, I suspect your CH gear has a low enough level of residual noise that noise won’t audible at any gain setting. In that case, it’s still worthwhile to experiment with different settings to determine if there is any change in sound quality. Go with whichever setting sounds best to your ears.