Best pot (Not Marijuana related lol)

[trixdropd]

So I wanna build a box to go in the fx loop of my amp that is a volume pot attached to a relay. The idea is that with the relay off the volume pot is active, allowing me to set my rhythem volume. I then turn the relay on via footswitch and get my full volume "lead" sound. I want a pot with the maximum usable range.

Thanks,

jeremy

[anchovie]

Maximum useable range? Any pot will go from zero to full!

[tiges_ tendres]

Do you really need a relay for that?  This could be done with just the pot and the switch.  In my experience, effect loops are much more prone to picking up stray clicks and pops from bypass switching.  I would assume it would pick up the relay clicking too.

Alternatively, you could have one switch select between two pots (One set Rhythm, one set lead) almost as easily.

I don't know what to advise you in regards to pot value.  I would assume that whatever the pot value in your guitar is would be a good place to start.

[trixdropd]

I should add that I've already built this. I tried a 10k audio taper and it does not allow full volume to pass through. I subbed a 500k out of one of my guitars and it is only really doing a lot in the lower range of the pot, though I do get full volume.
The relay caused no noise or clicks or pops whatsoever, and it allows the pedal to sit at the amp with a total of 1 foot of wire instead of 50' total to and from my pedal board.

[defaced]

With properly voltage referenced relay contacts, there should be zero clicking/popping or other noise from the relay - which is just a switch with a coil to actuate it.  A schematic of the amp's FX loop will tell you exactly what you have to do in terms of voltage referencing the relay contacts, if you need coupling caps inside your switch box or not, and how the additional volume pot will appear to the signal.  For pot values, start with whatever value is currently used for the volume pot in the amp.  If it's a tube amp, 1M and 500k audio taper are common values.  

[kurtlives]

Just use a value that matches the impedance of the loop. Your probably have a 12AX7 or something driving the loop. I'd try a 1M(A) pot.

As said, you don't need a relay for what your doing, unless you want this footswitchable.

[trixdropd]

Just use a value that matches the impedance of the loop. Your probably have a 12AX7 or something driving the loop. I'd try a 1M(A) pot.

As said, you don't need a relay for what your doing, unless you want this footswitchable.

it's a randall rg100es. can i use my meter to measure the impedance of the loop or is the schematic or taking the amp apart the best way to figure out the best value pot?
I also use a couple other amps from time to time so i'd like it to work with all of them.

And yes, I need this foot switchable, hence why I used the relay. it's kinda like a boost pedal, but not.

[space_ryerson]

Just use a value that matches the impedance of the loop. Your probably have a 12AX7 or something driving the loop. I'd try a 1M(A) pot.

As said, you don't need a relay for what your doing, unless you want this footswitchable.

it's a randall rg100es. can i use my meter to measure the impedance of the loop or is the schematic or taking the amp apart the best way to figure out the best value pot?
I also use a couple other amps from time to time so i'd like it to work with all of them.

And yes, I need this foot switchable, hence why I used the relay. it's kinda like a boost pedal, but not.

Funny that you should mention that it's a rg100es. The guy who designed that amp, Gary Sunda, later added what is known as a 'kicker', which does exactly what you are looking for. Initially, it was achieved like the lower right of this schematic. Later, this method was used.

On an unrelated thread, do you get bleed between the two channels? If so, I can post how to fix that.

[trixdropd]

Just use a value that matches the impedance of the loop. Your probably have a 12AX7 or something driving the loop. I'd try a 1M(A) pot.

As said, you don't need a relay for what your doing, unless you want this footswitchable.

it's a randall rg100es. can i use my meter to measure the impedance of the loop or is the schematic or taking the amp apart the best way to figure out the best value pot?
I also use a couple other amps from time to time so i'd like it to work with all of them.

And yes, I need this foot switchable, hence why I used the relay. it's kinda like a boost pedal, but not.

Funny that you should mention that it's a rg100es. The guy who designed that amp, Gary Sunda, later added what is known as a 'kicker', which does exactly what you are looking for. Initially, it was achieved like the lower right of this schematic. Later, this method was used.

On an unrelated thread, do you get bleed between the two channels? If so, I can post how to fix that.

I sometimes get a slight bleed on the channels. Like if the clean is on and i have the red channel gain cranked it will bleed though a bit.

[space_ryerson]

I crank the red channel a lot, so the leakage became the bane of my existence for a short while. This isn't the prettiest diagram, but when compared to the first schematic I posted, change the wires coming from the footswitch plug to match what I drew in red in this schematic. On the actual amp, it's just a matter of desoldering two wires, and resoldering them to one of the pot lugs in the gain controls nearby. The hardest part is getting under the PCB.