Volume pot necessary?

[Joecool85]

Do you really need a volume control on effects pedals?  Seems like a "set it and forget it" type of knob.  I've been thinking about building one with a trim pot so I could adjust the sound level to unity for when the circuit is on or off.

And before anyone says anything, it's been done.  The MXR Phase 45 has no volume control on it.  So...is it necessary?

[jacobyjd]

It completely depends on the circuit. For most distortions/overdrives, the gain control is interactive with the output level of the effect, so the volume control would be necessary to tame it. Also, many folks like to tune the amount of output level of an OD to drive the front end of their amps.

Usually you can omit the volume control in a modulation circuit (like the phase 45), or add a volume trimmer (like my tremulus lune).

[Joecool85]

It completely depends on the circuit. For most distortions/overdrives, the gain control is interactive with the output level of the effect, so the volume control would be necessary to tame it. Also, many folks like to tune the amount of output level of an OD to drive the front end of their amps.

Usually you can omit the volume control in a modulation circuit (like the phase 45), or add a volume trimmer (like my tremulus lune).

Ok, that makes sense.  I've been thinking about building another 5th Gear Overdrive and I was considering wiring in the gain at full since thats the only way I play it anyway.  Then I figured, hey just one knob, cool!  But it looks like I might be able to get away with no knobs and just have a volume trim pot hidden inside!

[Mark Hammer]

Some effects present no real change in output level when the other controls are adjusted.  A chorus is a good example.  In those instances, no further volume adjustment is really required, unless you have a good reason.  I have a Ross phaser clone I made that introduces some gain in the output stage.  Normally the output is terminated by a 150k fixed resistor.  Given the added gain, though, I swapped that for a 100k pot and a 51k resistor to ground, so that I could get a bit more than bypass level, and a bit less, permitting the pedal to be suitable to solos OR rhythm playing when engaged.

In the case of distortions, though, it is rare that one can get a change in tone without a concomitant change in level, that may or may not be compatible with what you're trying to do.

For EQ pedals, it can be the case that the tonal adjustments made have no clearly audible affect on overall volume, but some settings and control configurations CAN make the volume decidedly louder or softer, so a volume control is often included.

[jacobyjd]

It completely depends on the circuit. For most distortions/overdrives, the gain control is interactive with the output level of the effect, so the volume control would be necessary to tame it. Also, many folks like to tune the amount of output level of an OD to drive the front end of their amps.

Usually you can omit the volume control in a modulation circuit (like the phase 45), or add a volume trimmer (like my tremulus lune).

Ok, that makes sense.  I've been thinking about building another 5th Gear Overdrive and I was considering wiring in the gain at full since thats the only way I play it anyway.  Then I figured, hey just one knob, cool!  But it looks like I might be able to get away with no knobs and just have a volume trim pot hidden inside!

If anything, I'd suggest leaving the volume knob on the outside, even if you hardwire the gain. The main issue with multiple controls on a pedal is that things tend to get twitchy in live situations. Having a volume control on an OD pedal gives you the ability to make adjustments depending on the amp you're using (ever had to use a backup amp? Not pretty if you don't have a way to tweak your overdrive a bit to compensate for differences).

Then again, if you always run the same settings, having the controls fixed and hidden might be your best bet. In that case, it's a personal preference thing.

[Joecool85]

I was planning on building another one anyway, so I think I may try this as an experiment.  Worst case I end up adding pots later.  I always try to keep things as simple as possible and really live by the "less is more" concept most of the time.  I'll keep you guys posted.

**edit**
Now I don't know.  I might put a volume knob on it afterall, in case someone wants to crank the volume up when the OD goes on etc.  We'll see.  I might have to talk to a few other musicians and see what they say they would like to see.

[CynicalMan]

Also with distortions, ODs, and compressors, unity gain is dependent on the level of the input signal. So if you set it for unity gain for a guitar with hot pickups, it will be higher than unity for quieter guitars. My rule of thumb is that distortions, ODs, compressors, expanders, and other effects that change dynamics need volume knobs, and boosters, filters, and tremolos sometimes need them.

Edit: jacobyjd 2000 posts  

[Ben N]

Many, if not most, commercial modulation pedals lack volume controls. Occasionally this is an issue, as some have a real or perceived volume boost or cut (e.g. the Danelectro Cool Cat Vibe, Boss CE-2, my EH Electric Mistress, and old DOD chorus I used to love, etc.) Even on those, though, a true volume control is probably counterproductive, and a set-and-forget trimpot (or a shaftless, screwdriver-adjustable panel mount pot such as Mouser sells) makes more sense.

Besides dirtboxes, compressors also generally need volume controls, for the same reason.

[jacobyjd]

Edit: jacobyjd 2000 posts  

WHAAAAT!? I should probably get some work done...