Send & Return box.. volume/gain control help.

[msurdin]

Hey Guys.

I was reading about some send & return boxes that have "full range gain" adjustments.
On a cornish interview about one of his pedalboards for David Gilmour it said the following...

"Returns 1 and 3 have full range gain adjustments on the back panel so that any type of effects can be interfaced (pedal signal level or line level for rack units). Send-Return 2 is fixed gain at guitar level"

I was wondering if there is a simple vol/ gain control pot that I can put on my send and returns.

Just checking... this can limit and boost the amount of signal coming into the S/R?

Thanks guys!

Matt

[GibsonGM]

There's a couple of ways to do this, passive or active...typically, I'd suspect that this involves an opamp boost circuit, an active control, as a recovery stage for after you've run thru your effects.  That would also act like a buffer and keep things from muddying up. 
So, for each return, I'd try building a very simple opamp circuit with variable gain...100's of examples can be found on Google.   Then, by playing with input/output caps, you can set the voicing for how you want your rig to sound.  Seems to me, tho, that the level could be set at the last pedal in the chain prior to heading back into the return....

The passive alternative is just using a volume pot on the return ;o) 

[slacker]

you want the adjusticator http://www.geofex.com/circuits/Adjusticator.gif one on the send and one on the return. This will buffer the sound and let you cut or boost the send and return.

[msurdin]

If i use the passive version and just have a vol pot, will it just cut volume? Or is there a way to let it boost as well?

Thanks

Matt

[slacker]

If you do it passively you can only cut the volume.

[msurdin]

Whats the easiest way to make is be able to boost?
Is it possible to use a push pull pot, so when its pulled its boosted?

[msurdin]

I was thinking about this last night. I want to do the send and return with a dpdt. Can I have a push pull so when its in it will just cut and when pulled boost? I was thinking maybe using the ggg lpb2 for the booster..