Trying to avoid using a 3pdt to switch between two effects in same box...

[momo]

Me again..
Two effects wired in series, trying to find a way to use just one at a time or both.
I added a 2pdt switch to send the input signal either to one effect or the other, grounded the side of the switch lugs that were unused. That did not work, I had much crosstalk.
This is a Japanese switch from the 70s, great construction, but not good for signal isolation.
I do not want to use a 3pdt footswitch.
I have some small 3pdt toggle, but wiring that with the shielded forest of cables will be a challenge..
So..
I realize that if I cut power to one effect the signal won't pass....
any other options that are staring @ me right now?

:-)

[ElectricDruid]

I don't see how it's possible to do *one pedal*, *the other pedal*, or *both pedals* without using a 3PDT, or some other multi-pole or multi-throw switch. There's just too many things need to be changed between those situations. You could do it with *two* DPDTs easily enough - just a simple bypass for each one, job done!

If you're trying to avoid using a 3PDT then could you use a simple SPST and a relay or something? Knowing why you want to avoid the 3PDT might help us propose alternatives that would fit your needs.

[momo]

See this thread
https://www.diystompboxes.com/smfforum/index.php?topic=130305.0

I don't want to "stomp" on this one , it's more like a portable tube preamp with an added Supreaux Deux. Since the Sup circuit demanded 18v, I already had it with the VC preamp so I went for it.
Now I'm just trying to see the best way to bypass considering I'm dealing with lot's of sheilded cabling.
thanks.

[ElectricDruid]

So why not just use DPDT toggles to switch each section in or out?

[momo]

So why not just use DPDT toggles to switch each section in or out?

I was told these 2 circuits are out of phase relative to each other.
If it was not the case, I could join both effects at the end somewhere maybe with a pot, but no.
As I see your suggestion, they would need to be in parallel.

You know, my original thought was to bias the Supreaux so that it cleans up nice, and just have it inline, always on. Just clean it up if I want or not feeding the VC.
It sure would be simpler cabling, I just wonder about total noise.

[idy]

Its sounds like you need to get both working and then try them series to find if you like it. Then commit to switching.

[momo]

There will be tweaking for sure. The voltage from the wall wart will drop a bit with the VC in there, not much, but those fets....so I will bias them when both effects are pulling their current.

[Ben N]

So why not just use DPDT toggles to switch each section in or out?

I was told these 2 circuits are out of phase relative to each other.
If it was not the case, I could join both effects at the end somewhere maybe with a pot, but no.

Wait, what? I thought the two were in series? What you seem to be describing is parallel. Also, in series, phase doesn't matter.

[momo]

In series yes.

[ElectricDruid]

This is what I was thinking of:

Two circuits, each with a DPDT around it to switch it in or out. You can have one, or the other, or both in series, or neither.

[GibsonGM]

Like Ben was saying, the phase relationship doesn't matter if you are running things in series - only if you are running in PARALLEL.   Neither effect cares whether the signal coming in is above or below zero (or a bias voltage) at any given time.  Series effects are processing signals 'one after the other' in a straight line....linear...the effects cascade from one to the next.

Parallel effects process signals at the SAME time, as they would have branched out and been sent to 2+ effects at the SAME time...and when they recombine, as they must at some point to remain parallel - you can have cancellation and odd effects because the mixing signals would be at different places in their 'wave' (math happens).  If they were not being recombined - split and then sent to 2 different amps, for example - then phase would again not be any problem (and the name 'parallel' would not really be the right term for splitting signals and sending them to independent outs anyway).   It's all about the signal flow - drawing this out can be informative!     

Tom's diagram is the way to go..."A" is Supreax, "B" is VC.  See how they flow into each other, OR you bypass either of them.

[momo]

Thanks everyone for that!
I found these, easy to install and a nice push switch.