Multi foot-switching passive volume control stompbox

[BrownAle]

Hi All

I'm brand new here. I used to be an electronics tech a hundred years ago but have forgotten most of it now.

Anyways, I'm interested in making a stomp box that allows me to select different pre-set volumes. (I don't like using volume pedals.)

My idea is for four foot-switchable settings. I imagine each "channel" volume will use its own pot and footswitch.

Ideally I would not have to turn off one footswitch before selecting the next but I understand that might be my only option.
Also, ideally each position would have its own LED allowing me to know status.

I have four 100K audio pots, four SPST foot switches, four LED's and two mono 1/4" jacks.

Can anybody supply me with a schematic and easy directions on how to soldier this thing up.

Any and all help is greatly appreciated.

BrownAle

[jkokura]

You won't likely be able to do it with SPST switches. You'll need 3PDT's if you want to have an LED for each and have all of them be true bypass.

Luckily, the store here has tested 3PDT's you can buy! Check out the link to the store at the top of the page.

Unless you want to get into Relays and microcontrollers and have it get complicated and expensive very quickly, you'll have to turn each one on and off. HOWEVER, if you can make do with just two volumes instead of four, there is a layout at the bottom of the page here: http://www.beavisaudio.com/techpages/Switches/

That only requires two pots, 1 switch, and you can have either one or two LEDs. You'll need power for the LED's, so don't forget either a DC jack and/or a 9V Battery clip.

Jacob

[BrownAle]

Thanks Jacob

Can I not combine two of these circuits into one box to create my four volume settings? (Meaning four pots and two 3pdt switches)

Regards,

BrownAle

[Processaurus]

It's a very good idea, much more useful than a volume pedal because volume changes are consistent and easily repeatable.

http://www.geofex.com/Article_Folders/multivol/multivol.htm

[jkokura]

not really, at least not as effectively as you might imagine. This method of switching is an either or option. So you get two choices, but one of them is on at all times. If you add a second switch in, you'll effectively have two different volume pots on at ALL times. So your signal will always be going through two volume pots. If you want more than two pots, you'll need more than two switches.

Jacob

[BrownAle]

Ben

I love the idea of the box you linked to.

How much would something like that cost to make?

[jkokura]

That's the relay based with microcontroller option I mentioned. It's possible to do, but after shipping and then working out the issues, I'm not sure it would be less expensive than your other options. How good are you with electronics? Did you understand the schems completely and really follow along with RG, or do you have just a basic concept from all of that? I have trouble understanding all of that, and only get some of it. So if you can understand all that, I'd say go for it. If not, perhaps another suggestion will come along.

Jacob

[Processaurus]

The geofex design is neither relay nor microcontroller based, it uses standard CMOS logic and 4053 analog switches.  The chips would only cost a few dollars, as with most pedals, the main expense is in the footswitches, pots, knobs, and case.  One would need to be able to read schematics and lookup chip pinouts in their datasheets, etc., to be successful, but it isn't that complicated, just a lot of repetition.  The logic part makes a logic version of a old radio-style selector switch, where when you press one button it pops out the previous one.  This logic goes on to control several 4053 SPDT electronic switches, to connect the output stage to one of several volume knobs.

I would only make 3 or 4 presets on the Geo design, and leave out the volume pedal send and return part.