Gain Vs Volume

Handsome_Chris

I know from experience, but I would like to know the technical answer, why does one need less gain at higher volumes?   

ecc83

Handsome_Chris said:

I know from experience, but I would like to know the technical answer, why does one need less gain at higher volumes?   

Not entirely sure that is right? "Gain" is purely voltage amplification and you need more of it to get more volume.

There comes a point in any amplifier system that distortion starts and this causes compression which is a loss of gain (the in/out curve bends down)

VERY complicated, interactive system going on and one that is dfferent for every amp system and even the EQ settings.

Dave.

ICBM

ecc83 said:

"Gain" is purely voltage amplification and you need more of it to get more volume. 

There comes a point in any amplifier system that distortion starts and this causes compression which is a loss of gain (the in/out curve bends down)

... but counterintuitively *sounds* like more 'gain' to the player because it increases distortion, and makes the sound mushy and unresponsive. So when you're pushing the amp hard enough that this effect becomes noticeable, you need to turn down the gain.

ecc83 said:

VERY complicated, interactive system going on and one that is dfferent for every amp system and even the EQ settings.

Yes - especially when you get into the range of output transformer bandwidth narrowing and valve rectifier non-linearity.

Whistler

In really simple terms, we tend to think of gain as the input volume, that is, how much voluem do you want going through your pedals, your amp, your mixer. Volume we tend to think of output volunme or master volume. When you have the desired gain setting so that you have the sound you want, set the final volume control so that it sounds as loud or quiet as you, your audience or your computer likes.

Handsome_Chris

I may have asked the wrong question.  What I maybe should have asked, is why do you need less preamp gain/overdrive/distortion the higher up the volume scale you go?

ICBM

Handsome_Chris said:

I may have asked the wrong question.  What I maybe should have asked, is why do you need less preamp gain/overdrive/distortion the higher up the volume scale you go?

Maybe I confused you with too much technical stuff .

Short version - because turning up the volume increases distortion and compression in the power stage* which sounds like more gain and turns the sound to mush.

(*And speakers, usually.)

monquixote

I think it's not just power amp distortion but that you get more sustain from the coupling of the amp and guitar.

I found it really noticeable going from the same patches using iem Vs cabs on stage

p90fool

Interaction with the speakers is also a consideration. 

Handsome_Chris

ICBM said:

Handsome_Chris said:

I may have asked the wrong question.  What I maybe should have asked, is why do you need less preamp gain/overdrive/distortion the higher up the volume scale you go?

Maybe I confused you with too much technical stuff .

Short version - because turning up the volume increases distortion and compression in the power stage* which sounds like more gain and turns the sound to mush.

(*And speakers, usually.)

What may be confusing the issue for me is using modelling equipment.  I find that as I ramp the master volume up, the gain needs to come down. 

ICBM

Handsome_Chris said:

What may be confusing the issue for me is using modelling equipment.  I find that as I ramp the master volume up, the gain needs to come down. 

That sounds like the modelling has been done accurately.

ecc83

Hmm, still not sure what's being said here? There is the effect that a distorted signal always SEEMS louder than a clean one?

In fact you can have REALLY low distortion REALLY loud systems that do not seem that loud and yet they can be bordering on hearing damage levels.

The converse is I suppose the definition of "noise"? Subjectively it is unwanted sound so what you don't like sounds loud!

Dave.

prlgmnr

Handsome_Chris said:

ICBM said:

Handsome_Chris said:

I may have asked the wrong question.  What I maybe should have asked, is why do you need less preamp gain/overdrive/distortion the higher up the volume scale you go?

Maybe I confused you with too much technical stuff .

Short version - because turning up the volume increases distortion and compression in the power stage* which sounds like more gain and turns the sound to mush.

(*And speakers, usually.)

What may be confusing the issue for me is using modelling equipment.  I find that as I ramp the master volume up, the gain needs to come down. 

I suppose it depends on what's being modelled, some amps you'll get phase inverter distortion as you turn up the master, and some you won't. Or some you will on some channels and not on others. 

ICBM

prlgmnr said:

I suppose it depends on what's being modelled, some amps you'll get phase inverter distortion as you turn up the master, and some you won't. Or some you will on some channels and not on others. 

Yes, it can all be quite complex and interactive.

One of the reasons I tend to like much more powerful amps than I would ever need in volume terms is exactly because they *don't* do this as much. If you need more or less volume you can just adjust the final master volume/level control and not need to compensate by adjusting the gain or anything else. If you’re running a 100W amp at 10W or 20W there’s really no change in power amp or speaker compression.

WiresDreamDisasters

@Handsome_Chris ;

Are you turning the gain down because things start to sound harsh, or are you turning the gain down because of responsiveness issues, or are you turning the gain down just because that's the received wisdom?

Handsome_Chris

I feel that I should add some context to this.  The other guitar with a band I'm in needs development.   I've discovered that he's a campfire strummer as opposed to an electric guitarist.

One of the things I have to explain to him is how amps are to be used.  I don't want to go down the line of "You should do this because I do this!".  I want him to understand how to use his gear.

Note: he hasn't got an amp yet

57Deluxe

Gain vs Volume??

no - Tone...

Vaiai

I'd say the increase in gain compresses the sound and makes it quieter but also less defined so taking the gain back and putting vol up cleans it up and it cuts through and sits in the mix better?

MichaelAT

Yeah it's going to the right direction now. Esp. if you are in a band context, try different settings and just stick to what works best in the mix. If that is your goal.

My take on preamp gain vs overall (master) volume: for most amps, if you play at low volume and you want a distorted sound from the amp, you have to rely on preamp gain/overdrive. Often labeled input gain. When you gradually increase the (master/output) volume, other components of the amp get saturated and add distortion to the signal (as mentioned above - PI tube, speaker, OT etc). In order to compensate, you'd back off the preamp gain gradually.

You can hear the sound of the whole "system" reach saturation gradually with non-master volume amps. Here, there is not distortion at all usually at low volume levels.

But unless you monitor and compare the signal with a signal analyzer/scope, there is really no formula on how to set the preamp & master amp.