Custom Loopers and A/B/Y's

[drummondrs]

HI, I am building a couple of loopers but I have questions. True bypass is a necessity
1. How do I add a feedback pot? I searched and came up with this http://www.diystompboxes.com/sboxforum/viewtopic.php?p=153932&highlight=#153932
However, that doesn't show clear wiring
2. How do you do two or more loops? I can only do one at the moment
3. How do you add blend pots with SPST switches on/off? Can't find any info
4. What sort of resistors do I need for an A/B/Y?

If people could explain wiring like this
http://www.diystompboxes.com/tbbox/tbbox.jpg
I would be unbelieveably grateful. Many thanks.

[drummondrs]

Sorry but BUMP

[lethargytartare]

Hi!  I'm knee-deep in the same sort of questions, and I /may/ be able to help a little...or at leat tide you over until someone more informed comes along...

1. that thread you found should answer your question -- you stick a 500K pot between the signal lugs of the effect send and return jacks.  I'm not sure what that does, but that's what the guy's diagram shows.  He mentioned that he updated the diagram, so maybe take another look at it and see if it's clear now.  If you're just not familiar with the diagram symbols, the red zig-zaggy thing with an arrow pointing down on it is the pot; the arror is the wiper/middle lug; and then the two sides of the zigzag are the two side lugs.

2. dunno -- trying to figure that out too :-)

3.  well, a spst just allows a signal to pass through or not.  so there's a signal in wire, and a signal out wire.  the signal out has to go, ultimately, to the output jack.  so, if you have multiple out signals you want to blend, you just need to get them connected to a blend pot, and have an output wire from that to the output jack.  does that help?

4. no idea -- I think the thing that makes that difficult is the Y/splitting.  the GeoFex site has one, and GGG has one called the parallizer -- but the author there just dictates several "sub blocks" but doesn't put it all together for you, so it's more educational and less immediately helpful.

As for that switch wiring, it's essentially the same as any true bypass 3PDT wiring.  In the ON position, the middle lugs are connected to their corresponding top lugs.  So, GUITAR IN links to EFFECT IN (which is actually effect SEND), the LED array links to the battery (to turn on), and the pedal's final OUTPUT links to the EFFECT OUT (or effect RETURN) -- so the signal goes through the effects chain before finally going to the output and on to AMP/NEXT PEDAL.  
In the OFF position, , the middle lugs are connected to their corresponding BOTTOM lugs.  So, GUITAR IN links to a lug that is directly connected to another lug that is directly connected to the pedal's final OUTPUT -- so the signal BYPASSES the effects chain and goes directly to the output and on to AMP/NEXT PEDAL.  The LED array is left hanging, so does not light up.

I tried my hand at diagramming how these 3PDTs are typically wired, and maybe it will help:


Good luck!

ltt