So I just got my guitar, for the amp I am using the Yamaha THR10II. It doesn't produce any sound when the gain is all the way off. What I'm doing now is turning it up just a little so the amp is able to produce sound. Is this normal?

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    One way to think about this is as the result being gain x volume. Zero x anything is zero, so if either gain or volume is set to zero, you’ll get no sound. Oct 28, 2020 at 13:36
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    What guitar are you using? Unless it is active and has a built in amplifier, then it would be strange for it to have a knob labelled 'gain'... Oct 28, 2020 at 14:01
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    @topoReinstateMonica - most likely the 'gain' pot is on the amp.
    – Tim
    Oct 28, 2020 at 14:54
  • Most amps have no output with the gain all the way down but some amps do. My Fender Rumble bass head outputs sound to the master at zero gain for example but is the only amp out of 4 I currently own that does this. Oct 28, 2020 at 18:03
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    What did you expect? What happens when you turn the volume knob on your hifi down to zero? A gain is nothing but a volume control on an input, volume or master is the volume control for the output. Both may be turned to zero, and both need to be non-zero to hear something. Oct 28, 2020 at 23:44

7 Answers 7


Yes it is normal.

The gain is the volume control of the input of the amplifier.

The signal flow of the tube amplifier goes:

Gain (preamp input) to tone stack (eq) to phase inverter stage (input to power amp) to power tubes (amplifier).

Amplifiers that simulate a tube amp follow a similar signal flow.


Gain is the input level control, it decides how hard the input signal hits the preamp. Guitar amps often exploit the effect of hitting it HARD, overdriving it into distortion.

Volume controls how much the output from the preamp is amplified. Again, specifically on a guitar amp, there may be the possibility of driving the speakers into interesting overload distortion.

On some models the Gain control just goes down to a level expected not to overdrive the preamp. On others it goes down to zero. Either design is 'normal'.

I would generally expect a Volume control to go down to zero.

  • 4
    This reads clearer than the accepted answer, and points out that gain may go to zero or not depending on design. Oct 28, 2020 at 21:51
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    And I just got a 'Populist' badge for it! Who'd have known!
    – Laurence
    Oct 31, 2020 at 15:26
  • Holy, moly! look at the up votes. Well, there is some justice in the this world after all :-) Oct 31, 2020 at 15:29

Effectively, there are three controls to your equipment. Volume on the guitar, volume on the pre-amp stage of your amp., and volume on the post, or amplifying stage of your amp.

With any one of those turned all the way down, the signal will not get through its entire path. Guitar volume down - there's no signal from the guitar. Gain down - the guitar signal is not allowed through to be amplified. Output volume on amp., down, any signal won't get amplified.

Those knobs (pots) work as calibrated switches. If any one is off, there's no sound.

  • 1
    "Those knobs (pots) work as calibrated switches" Well, no they don't. They act as pots. Whatever a 'calibrated switch' is?
    – Laurence
    Oct 28, 2020 at 14:28
  • @LaurencePayne - layman's terms. They go from completely off to completely on gradually. Graduated is a better word.
    – Tim
    Oct 28, 2020 at 14:51
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    "switches" is a wrong word
    – blueskiwi
    Oct 28, 2020 at 21:04
  • @blueskiwi - that's why it was in inverted commas.
    – Tim
    Oct 28, 2020 at 21:14
  • The point being that the first control on a guitar amp, marked 'gain' or possibly 'overdrive' sometimes doesn't go down to zero signal pass, just to zero overload of the next stage.
    – Laurence
    Dec 7, 2023 at 22:53

Yes, at least some gain is needed. When it's turned off, no signal is being sent from your guitar to the amp.

Gain defines the signal input level to your amp. Thus, if set to 0, there will be no sound produced.

Volume defines the output level of sound.

For example:

Both gain and levels refer to the loudness of the audio. However, gain is the input level of the clips and volume is the output. (SOURCE)

For a guitar-specific example, Fender has an explanation on their website.

A guitar amp can be thought of as a device that has two stages. A relatively weak signal goes from your instrument into the first stage, where it is processed and handed to the second stage, which boosts it into a strong signal-the sound that then comes out of the speakers and rocks the Casbah.

You might also find this post from Sound Design SE helpful: How do you use gain effectively?


In terms of the electric circuit in the amplifier, gain is defined like:

V(in) x Gain = V(out)

That is, it's not added to the input, it's a multiplier. If you turn the gain down to zero, the output goes to zero as well.

Strictly speaking, "zero" on your amplifier likely doesn't correspond to a gain of zero. The signal coming out of your guitar is too quiet to be heard on its own, and there's a minimum level of amplification needed in order to overcome the electrical losses inside the amplifier and produce something loud enough to hear. "Zero" on an amp generally corresponds to "inaudible", and "Zero plus a smidge" corresponds to "minimum gain required to be barely audible".

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    For a guitar amplifier, I'd describe the behavior as V(out) = Volume x Crunch( V(In) x Gain)). If the V(In) x Gain level is below the point where the crunch affects the signal, the amp will produce a clean tone. The higher that level gets beyond that point, the more distorted the signal will become. Many guitar amplifiers either bias the gain knob so that at its lowest setting, the (V(In) x Gain) level will be just short of the crunch point when the guitar is played loudly, or else have a switch to behave as though the knob is at that position.
    – supercat
    Oct 29, 2020 at 15:50

There are at least 2 ways do indicate a gain: in linear units or in logarithmic units (dB).

0 gain in linear units means no signal at the output. You may as well have partial gain (0.1 means 1/10 of the input signal goes to the output).

0 gain in dB means the signal level is not changed. Positive dB values mean increase (amplification), negative - decrease (attenuation) of the signal level. +3dB means 2x increase, +10dB means 10x increase, etc... and -3dB means you get only half of the signal level at the output.

Your gain knob may be labeled either in linear units, in dB, or in some cases, both.

  • In the dB-type gain case, how is zero actual output accomplished?
    – Aaron
    Oct 29, 2020 at 19:05
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    @Aaron in theory, it is not accomplished. Zero actual output would be minus infinity in dB. In practice, it is also not fully accomplished as any electronic circuit has some parasitic paths of the signal propagation. Then again, you don't need to go down to zero. You just need the signal to become inaudible. And the distance between the hearing damage and inaudible sound is ~100dB
    – fraxinus
    Oct 29, 2020 at 19:12
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    Well... even an unplugged electric guitar produces some audible sound in purely acoustic way. So no complete happines in unplugging, either.
    – fraxinus
    Oct 29, 2020 at 19:36
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    @Aaron In practise, you don't actually get a logarithmic control in dBs. What you get is a control with two (or sometimes more) straight lines which is "kind of" logarithmic over the main range of the control when it's on. It's still fully off at one end.
    – Graham
    Oct 30, 2020 at 8:58
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    It's good to mention linear and logarithmic units, however guitar / amp knobs usually use neither. Gain should use a “logarithmic tapered” pot (in practice, these aren't really logarithmic, just slower-acting on the lower half of the range), but they're almost always labelled just with an arbitrary 1-10 scale. Oct 30, 2020 at 9:23

Man, that's normal, no gain no signal, when your gain knob is set to zero, it's not zero, you just can't hear it, turning the gain up is the only way to drive the signal from the guitar. Everything we use, mics, guitars, headphones require a certain amount of gain. Good luck!!

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