Adding an FX Loop to madbean delay projects?

[claytushaywood]

I've been trying to figure out how to do this forever, with no luck.  So anyone with the skillz or someone that has seen info on this posted elsewhere that could point me in the right direction- would be greatly appreciated!

I'd like to add an effects loop to pretty much any delay circuit I can.  I'm open to whatever you know.  I'm interested in adding other effects into this loop and having the repeats only of the delay be effected by whatever is in this loop.  I've heard that some ways to implement this have the signal get more and more effected with each repeat.  and others just have it effected the same amount.  ie: if you put a pitchshifter at 1 octave down in the loop- the first type would have the repeats progressively go 1 octave down with each repeat.  the latter would have all the repeats at one octave down.  I'd be interested in either or both!

I imagine I would just route the signal from the feedback pot somewhere and send it to a switching jack for the send and return.  I've tried this according to something I found a while back and I actually got crazy loud distorted oscillation whenever I put any effect in the loop- regardless of the volume and settings.  But the delay worked just fine when I patched the send and return jacks with a cable.  Would there need to be some sort of decoupling capacitor used or something?

Sorry i know i dont have too much technical knowledge- but i'm trying to learn and anything that would help send me on my way would be awesome! 

If anyone knows how to implement this on the sea urchin, DMM, dm2, echo base, cave dweller, aquapuss- (apparently this mod cannot be done on the multiplex) let me know!

[gtr2]

Something similar to this should work.

The in and out would connect in the wet/delay line and the fx send/return would be connected to jacks with the sleeve grounded.

You may have to play with the gain of IC1A.  This isn't a verified circuit but I think it will put you in the right direction.  The mix pot will allow you to adjust the incoming fx back into the delay line.  The component #s are goofy because I just did some cut and paste from another circuit.  If I were to use this I'd also change a couple values and there are a few things that could/should be eliminated.  I may try something similar to this if I have time and create a project just for the fx loop pcb if there is enough interest.

Josh

[gtr2]

Something small 

[lincolnic]

I would definitely buy some of those PCBs if you made them!

[jkokura]

Josh, that would make an excellent addition to the Modular Tap Tempo Delay set of PCBs I'm creating. The Delay will feature a send and return for the repeats path, and that loop would easily be able to be mounted to jacks that would send and return to another effect, or feature an effect in the same enclosure. That would even allow it to be foot switchable...

Jacob

[claytushaywood]

sick!  so this is like a buffered blendable circuit?  I would definitely buy this pcb for every delay I build!  Would you be able to implement this circuit into the multiplex?  cuz that would make it THE ultimate delay circuit

[gtr2]

Well tonight I'll do some breadboarding and hack it in to a few delays I have laying around.

I believe it will work ok with the multiplex depending on where it gets tied in.

That sounds cool Jacob.

Josh

[claytushaywood]

Did you end up trying this josh?  I'd love to hear about it!

[gtr2]

It didn't work like I had hoped.  For a few reasons.

I did tap straight out of a multiplex board, it actually plays nice with no adjustment with Boss pedals.  I tried a chorus and boss tremolo.  It worked ok with a EH mistress, not as well as the boss.  So there is something to the buffer with the boss's.  Didn't look into it any further.  Backlogged...

Josh

[jeffaroo]

keep pounding the forums
ive seen something about this. problem is im on 5 forums
i forgot where i seen it. i will keep my eye out
and 1776 is right it has something to do with where its tied in at.
echo-plex all the way its like shoving david gilmour in a box

[jeffaroo]

 

[ThePastRecedes]

I'm thinking of adding a effects loop for my multiplex and I'm wondering why there is a need for the extra circuitry. I assume it's to avoid volume loss right? But whys it needed because most well designed pedals are designed for at least unity gain.

Thanks in advance!

[ThePastRecedes]

No update? I should stop being so impatient 

[Thomas_H]

The extra circuitry is needed to decouple the signal to FX Send and couple it back with the right volume and no side effects to the existing effect and such.
You cannot just cut the wire and name it send/return but you might want to try it to learn more about it.

[timbo_93631]

I was thinking of trying this on a Multiplex using JMK's Panner to mix in the FX loop, looking at the schematic of JMK's Modular Delay I see how the return should basically be on pin 6 of IC1, but I am wondering where the Send would be implemented the best on the Multiplex.  Lug 2 of the mix pot?  Or would I take the signal from the lug 3 pad on the Mplex pcb and run it to the in of the panner, and panner out to lug3 of the mix pot?