2 PCB Pedal Parallel Questions

[byrnej]

I'm interesting in doing a 2 PCB pedal with a single foot switch. There's a basic diagram here with the boards running in series: http://wiki.pedalpcb.com/wiki/2-in-1_Pedal_Wiring_(Single_Footswitch)

If I connect the top left (using pic of for reference, lug #1) lug of the footswitch to both "INs" on the PCBs and the top right lug to the outs would that make the PCBs run in parallel? What are the downsides of this? Any type of phasing or cancelling?

Also, if I wanted to take the outs from the PCB and run them to a potentiometer could that be used to create a blend of the effects. Out from PCB #1 to pot lug #1, Out from PCB #2 to pt lug #3 and then pot lug #2 as my out. Would any of this work? Or could I use a dual pot and blend them like you can with two guitar pickups? If yes for either of these, what pot value should I use?

 

[Chuck D. Bones]

It is possible to connect two effects in parallel, but there are challenges. As you mentioned, phasing / cancelling can and will probably happen at some frequencies, depends on the two effects. A blend pot would definitely be a good idea. A single pot would work. Without the blend pot, the two effects would have a tug-of-war and the one with the lowest output impedance wins. Then there's the issue of which effect is loudest. The one with the least compression would dominate during and right after the note attack, the one with the most compression would dominate as the note fades out. Might sound good, might not.

Which two effects did you have in mind and what are you trying to accomplish? There's a reason most people put effects in series rather than parallel. You may find it just doesn't do what you want or you may discover a whole new sound. Try it and see.

 

[byrnej]

Thanks for the response.

It's more of an experiment on my end and I completely understand why people go for series rather than parallel. I just wanted to see if there is any feedback like "No, just no. It's a waste of your time and you'll start a fire." Right now, I have a few pedalpcb boards hanging out, I was going to try a fuzz (probably the hyperion since it's a small 2 knob board) and rat in parallel and see what happens. I just want a knarly, dirt distortion and fuzz that may be unique. I figured those might be a good first try since they are not completed different sounds like trying a reverb and distortion together. If it doesn't work I'll probably hook them in series.

For a blend pot do you have any suggestions for value? I have a couple of extra linear pots hanging out: 1K, 5K, 50K, 100K.

 

[Betty Wont]

Check out the JMK Paralyzer project. I really enjoy parallel dirt.

 

[Chuck D. Bones]

In the case of those two pedals (Ionizer & Rat), the volume controls are at the end so they can be your blend control. Just put a 47K resistor from each pedal output to the shared output jack and you're ready to experiment. If you're dead set on having a blend pot, use the B100K. You want a resistance that is similar to the volume pot resistance. Both of those circuits are non-inverting, so at mid frequencies, they will not cancel. Harmonics created by the distortion part of the circuits can have any phase, so some will reinforce and some will cancel. Should be interesting.