What does gain do that volume doesn't?

[Fiftyfifty]

Now I've read all those explanations telling us how one functions at the input stage and the other at the output stage, etc. My question is not about the technicality about how gain is different from volume, but how it changes the way we hear music.

Would like to hear FM's thoughts on this subject.

 

[Decadent_Spectre]

In my experience (with PC source systems) is that digital "volume" doesn't really have much of an effect but amplifiers can sound a tad different at different gains, if they have the option to control gain.

Edit: This assumes you have accounted for the difference in volume by adjusting it in the PC.

 

[Kannan]

Gain essentially is the drive capability of the output stage to power the next input stage. It is not like the attenuation of the signal.
Some power amplifiers are provided with input gain (especially in car audio and pro audio) so that it can be connected to varying types of input loads from low gain output stage to high gain output stage so that the power amplifier is not over driven or under driven.

Gain pots can be commonly seen in digital sound processors, power amplifiers, parametric equalisers and some other pro audio mixers.

Coming to how it changes the music, if not matched properly, you will either loose dynamics or introduce distortion. When properly matched it should not make change to the music.

 

[Decadent_Spectre]

Gain essentially is the drive capability of the output stage to power the next input stage. It is not like the attenuation of the signal.
Some power amplifiers are provided with input gain (especially in car audio and pro audio) so that it can be connected to varying types of input loads from low gain output stage to high gain output stage so that the power amplifier is not over driven or under driven.

Gain pots can be commonly seen in digital sound processors, power amplifiers, parametric equalisers and some other pro audio mixers.

Coming to how it changes the music, if not matched properly, you will either loose dynamics or introduce distortion. When properly matched it should not make change to the music.

Not sure what you mean by this. The gain in pro amps is fixed, you attenuate the signal input, is this what you meant?

 

[Kannan]

The gain in pro amps is fixed, you attenuate the signal input, is this what you meant?

To attenuate, a gain pot is usually provided in pro audio and some high end amps. This helps in using varied sources.
It should ideally be set to the lowest gain for best performance.

 

[Fiftyfifty]

Coming to how it changes the music, if not matched properly, you will either loose dynamics or introduce distortion. When properly matched it should not make change to the music.

This is indeed borne out by my own experience! At a higher gain, I hear a. better dynamics; b. the centre image comes forward; and, c. there is some distortion that can be mistaken for 'live' sound. With the lower gain setting, distortion goes away, clarity improves, but I lose some dynamics. My amp doesn't have a gain pot, but has low and high gain settings.

 

[Decadent_Spectre]

To attenuate, a gain pot is usually provided in pro audio and some high end amps. This helps in using varied sources.
It should ideally be set to the lowest gain for best performance.

In pro amps I have only seen gain controls, to my knowledge these only attenuate the input signal whereas the actual gain of the amp ( amplification of the signal in x db) is fixed. Therefore a higher level input is attenuated with low gain settings thus resulting in lower output. I have not seen "volume" settings in pro amps.

Personally I don't run it at max or min as it doesn't sound right to me.

 

[keith_correa]

The so called "gain" pots at the input in pro amps - don't they just serve to pad the signal? Not really gain control at all? Variable gain amplifiers are a totally different animal, no?

 

[arj]

Now I've read all those explanations telling us how one functions at the input stage and the other at the output stage, etc. My question is not about the technicality about how gain is different from volume, but how it changes the way we hear music.

Would like to hear FM's thoughts on this subject.

I have gone through this very question since i had a problem of low gain and the volume control could not fix. the way I understood it is that the gain happens to the signal during amplification where primarily the current is increased and as gain increases the tonality of sound changes

Volume control happens to the signal after amplification and does not impact the tonality and its the voltage which is changed. the overall gain of a Pre+ amp needs to be around 27-35 approximately. too much gain and the sound gets saturated and too less it cannot drive the speaker and hence a lack of bass and hollow sound..

 

[Decadent_Spectre]

The so called "gain" pots at the input in pro amps - don't they just serve to pad the signal? Not really gain control at all? Variable gain amplifiers are a totally different animal, no?

Pro amps AFAIK have fixed gain as I mentioned.

 

[keith_correa]

Pro amps AFAIK have fixed gain as I mentioned.

Not all do. Some have variable gain.

 

[Decadent_Spectre]

Not all do. Some have variable gain.

Can you link to an example?

 

[keith_correa]

Can you link to an example?

Crown 2502 I think has variable gain.

 

[Decadent_Spectre]

I don't think it has an actual variable gain but is a regular pro amp. The gain is fixed and you adjust the knobs to attenuate or "open" the signal as far as I can tell. It's owners manual does not list much info.

The manual lists a input sensitivity selector but does not list how it works or the fixed gain.

 

[Hari Iyer]

Earlier I was using an dual JFET input preamplifier which had a gain of +6dB. This was extreme low noise and distortion. Even then it had the signature of the active and passive components in series.

Last year I built a passive preamplifier with constant input impedance and which basically is an attenuator device and not a gain device. The passive preamplifier sounds more accurate without any colouration to the original signal that comes from my source. With the active gain control the vocals though more lively were not 100% accurate.