Multiple Fx on one pot? Circuit switching?'s

[Karmasound]

This question is multiple part.


1) Let's take the basic Fuzz Face circuit. Now say I made 4 pcb cards. Basically 4 FF's with a few different tweaks.  Say I  didn't want to put each on a stomper.

A)Could I tie all of the 9v+ to one batt.

B) Tie the grounds together

C) Using a 2 pole rotary would I tie the In and out to the on/off DPDT?

D) Tie the in and out of each Fuzz card to it's respective lug on the rotary?

Would this work ok? If not could you explain how.


2) Would I be able to take one pot for the volume and make a master volume for each of the cards.  Wire 4 wires to the pot and then to the respective card?

A) Would I need a dual gang pot? Another type pot? Would I just need 2 dual gangs?

B) I would like to do this for the fuzz pot also.



3) Say I wanted a 2 pole 6 position rotary for input cap switching.

A) Would I be able to tie all of the cicuit cards to the two main poles?

B) Could I use just that one rotary to switch caps for whatever card is activated?

:shock:  

[Karmasound]

Daytime bump

[R.G.]

Yes, you can do all of that, and you may do all of that.

However, this setup will likely result in some massive pops when switching, and possibly other ill effects such as oscillation by the other three circuits that are not being used. Depending on the details, you may kill or degrade transistors by abusing the base emitter junction.

But you can, and may. It might serve your purposes if you want to take the time to turn power off, switch, then power back on.

It will take some thought about how to avoid switch transients and oscillation while switching.

[Mark Hammer]

Last year, I made myself a single board with (thanks to Francisco Pena) a Distortion+, Blue Box, BMP, Ampeg Scrambler, TS-9, and I think one other fuzz.  The populated board still awaits purchase of all those pots and hookup wire, but the intent was to stick them in a single chassis with a similar rotary switch, though I was pondering dividing the assortment up into a Station 1 and Station 2 cluster.  So, it is do-able.

Just note, though, that simply because you aren't listening to a given circuit at the moment doesn't mean it isn't "on" and still consuming battery current.  For that reason, especially if you want to use some sort of LED status indicator, either a 6-pack of AA's or an external adaptor is recommended.  Even the best of 9v batteries won't last long powering 4-6 circuits at once.

Also, as RG wisely notes, placing multiple high-gain circuits close to each other in the same chassis is not without sonic risks from oscillation.  If you can find yourself a cheap supply of those multi-conductor shielded cables that connect CD/DVD drives with your sound-card, they make a great source of suitable gauged shielded hookup wire for pots to keep stray signals from straying farther.  As an added bonus, you can use headers on your board and make use of the connectors at the end of those cables to connect/disconnect your controls.

[Karmasound]

Does wiring them on the same switches cause the osc. problems or just being in the same box?

[R.G.]

Does wiring them on the same switches cause the osc. problems or just being in the same box?

Yes.

[Karmasound]

What about sharing a power tap? Four wires, so only one plug per box?


Could they all run off of one ac adapter?




I'm not being lazy. I would test all of this out myself, but I don't have the parts right now. I'll be making an order soon, i'm just getting some ideas

[R.G.]

What about sharing a power tap? Four wires, so only one plug per box?
Could they all run off of one ac adapter?

Yes, if each effect is properly bypassed on the effect board and if your ground wires for each effect are set  up so that current from one effect does not travel down the other effect's ground wire.

[Karmasound]

Awesome this is sounding better everyday.



It's amazing how one can minipulate and manifest what one needs!