• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join free Log in
    Want zero display ads or expanded classifieds tools? Compare plans.

What's the difference between Gain and Volume?

#2
Gain is the volume to the preamp section. Volume turns up the power amp section. If you have both knobs on one amp, this is still true.

Not a dumb question at all. The gain usually has a light next to it. Turn it up until the light blinks a little when you are playing hard. Then turn up the volume until you are as loud as you want to be.:bassist:
 
#6
Since time immoral, amplifiers have been broken up into two general sections. A preamp works with (relatively) low voltage and current levels, contains the controls, and boosts the signal up to a certain level where the power amp can take over and provide the rest of the boost.

The power amp is typically simplistic in what it does, providing the final amount of amplification to drive the speaker at high voltage and current. From a design standpoint, the power amp is its own beast because it requires consideration of relatively high voltages and removal of waste heat.

Anything that can run on lower voltages found in the preamp, can be simpler and cheaper if it is designed into the preamp instead of the power amp.

A bass head contains both preamp and power amp, but they are typically separate circuits within a single box. In both of my amps, the power amp is on its own circuit board that is attached to the heat sink, whereas the preamp circuit board is attached to the control panel.

In a tube amp, the demarcation is a bit more arbitrary, but the power amp usually starts after the master volume control.

Strictly speaking, gain is the ratio of the output voltage to the input voltage, usually expressed in dB. The difference between gain and volume in an amp is largely semantic. Of course volume also refers to how loud the sound is when it reaches your ears.
 
#7
fdeck said:
Since time immoral, amplifiers have been broken up into two general sections. A preamp works with (relatively) low voltage and current levels, contains the controls, and boosts the signal up to a certain level where the power amp can take over and provide the rest of the boost.

The power amp is typically simplistic in what it does, providing the final amount of amplification to drive the speaker at high voltage and current. From a design standpoint, the power amp is its own beast because it requires consideration of relatively high voltages and removal of waste heat.

Anything that can run on lower voltages found in the preamp, can be simpler and cheaper if it is designed into the preamp instead of the power amp.

A bass head contains both preamp and power amp, but they are typically separate circuits within a single box. In both of my amps, the power amp is on its own circuit board that is attached to the heat sink, whereas the preamp circuit board is attached to the control panel.

In a tube amp, the demarcation is a bit more arbitrary, but the power amp usually starts after the master volume control.

Strictly speaking, gain is the ratio of the output voltage to the input voltage, usually expressed in dB. The difference between gain and volume in an amp is largely semantic. Of course volume also refers to how loud the sound is when it reaches your ears.
Click to expand...

I almost understood that...:(
 
#8
Maybe a "more simple" way to look at it is this:

In a regular "Bass Head" it contains both your pre-amp and your power amp. Everything that shapes your tone (before the effects loop) is considered your pre-amp. The final satge (output or volume knob) is your power amp.

In a component setup, the pre-amp does all of your tone shaping, but no amplifying of the signal.

All a power amp does is to take your signal and crank up the volume.
 
#9
Adding to fdeck's excellent post, gain can be measured in exact mathematical terms, as apposed to volume that is generally a relative, inexact term. In other words, when engineers talk about the amount of increase in voltage provided by an amplifier, they use the term gain, not volume.

That is not to say the using the term "increase the volume by 3dB" isn't correct, it is. However that relates to sound pressure level from the speakers, not the amount of increase in signal inside an amplifier.
 
#18
My 2 cents. Gain and Volume are electric music (electrical instruments) terms that are often used interchangeably. Is there a difference in their meanings and, if any what is it? The Gain knob controls the input sensitivity of either a pre-amp or a power-amp. On my SVP-Pro pre-amp it is the knob right beside the input jack. I’m not sure but I think it’s labeled “input gain” or something like that. On my QSC-PLX-1202 power amp there are 2 knobs (stereo) on the front and they control how sensitive each channel is to the input from the pre-amp or soundboard or whatever is sending it a signals. The closest thing I have to what might considered a “Volume” knob would be the “Master” knob on the pre-amp. It controls how much signal is sent to the power-amp. It is located at the end of the pre-amp signal path. So you see, on my rig I no less than 3 knobs that control how loud or the “Volume” of my actual sound coming from my rig. Why are 3 knobs better than just 1 “Volume” knob? Distortion and Noise control. If the “input gain” on the pre-amp is set too high the pre-amp will send the power-amp a distorted signal. (in some cases this is desirable) If it’s set too low than the “Master” will have to cranked clear up and the gain knobs on the power-amp will have to cranked clear up to get enough “Volume” and this often adds hiss and noise which is rarely desirable. If the “Master” is set too high then power-amp gain knobs will have to be turned down or the power-amp will be overdriven causing it to clip and adding distortion to the final sound. Some times this is desirable with tube amps but never with transistor amps. So with 3 gain-volume knobs you can not only control the volume of the final sound but also the amount of distortion and noise that may be present your final sound. Gain controls usually are placed at the beginning of the signal path and "Volume or Master" controls are usually placed at the end of the signal path. So what about my small PV Minx amp that only has one Volume knob and no Gain or Master? It's just a gain knob at the beginning of the signal chain. The power-amp section is wired directly to the preamp section and there are no controls at the input-output sections of these stages. You just turn it up if you want more "Volume" and down for less.
 
#19
Gain comes at many stages in a head or preamp/power amp combination. Pre-gain or trim is used to best match the bass to the input, and can also depending on circuit design be used to get overdrive/saturation. Then comes EQ and maybe some contour switches/buttons that also can add some gain. By the time you get to the post-gain you are essentially using it as a volume control to actually set the level you want to have for performance. So it is often labeled MASTER VOLUME.
 

Latest posts

Top Bottom
Back