Switching FX between series and parallel

Working on a way to switch FX between series and parallel modes using relays.

This will actually be for 8 different FX units, but the attached diagram shows 4.

Hoping to confirm that this layout would work ok, and also - would anyone be able to advise on the best option in terms of the relays?  I'm seeing that multi-pole relays are often really expensive.  I'm wondering what the most cost effective route would be that will keep the integrity of the audio being passed through it.

Missed a few connections, here's the updated schematic...

A couple of other questions I have are:

1)  Should those top 3 relays be grounded or just dead ends?  Would that mean signal wouldn't make it to the effect when in 'series' mode?

2)  Can i keep all the grounds hardwired despite the switching between series and parallel?

1) Consider what happens if  you switch the upper relays to ground. You will ground the inputs of FX1, 2 and 3, and get no signal through the chain at all. Leave those connections open -- don't ground them.

2) Yes.

Thanks Hideki!    The grounding was a 'duh' moment for me.  :-|

This unit will need 2 sets of 6pdt relays.  Any suggestions for handling that?  Single unit / multiple relays better in terms of price and/or sound quality?

Hello and welcome,


remember that 8 units in parallel will decrease the impedance seen by the sending unit,so be careful and check if it is capable to drive the fx.
E.g. all fx had an input impedance of 10k ohms the result is 1k25 ohms,if they are 20k ohms the result is 2k5 ohms etc.
Best to have something in front of the relay circuit to split the signal.


Eight fx,in parallel or series, might also cause a serious noise level..........I wonder what your goal is........


Just my 2ct,


best regards,


Udo.

Hi Udo,
Thanks for the input!

It is actually 2 different sets of 4 fx units - independent of each other.

I have 3 solidstate and 1 tube effect and simply want to be able to run them in series or parallel.

So, given that it's 4 effects, I would need a buffer to handle the impedance changes?

expat said:

Hi Udo,
Thanks for the input!

It is actually 2 different sets of 4 fx units - independent of each other.

I have 3 solidstate and 1 tube effect and simply want to be able to run them in series or parallel.

So, given that it's 4 effects, I would need a buffer to handle the impedance changes?

Click to expand...

Hello,


once Joe Malone told me that modern gear nowadays should drive impedance loads down to 2k ohms or so,so it might work.
If I were you I'd simply make a mult of y-cables or anything like that and check out if it works o.k. for you.
If not (audible signal degradation etc.) buffering might become necessary.
Good to use a summing stage on outputs of course.


Have fun,


Udo.