feedback looper with a momentary switch?

[LateCentury]

Hey there...

I just tried to make this:


Only with a momentary switch instead of a typical 3pdt. What happened when I powered it up was that the switch was on and carrying the feedback loop signal (with a delay pedal in the loop), only when I pressed the switch, the signal cut out and it started feeding back the leftover delay signal repeats. So, technically, the feedback loop works... but I don't understand why its cutting my signal. I tried eliminating spdt switch and connecting the 1 terminal of the pot to the center lug. Same result.

Am I misunderstanding how momentary switches function? They shouldn't cut the signal out, right?

[Drew Hallenbeck]

If it's a three pole, double throw switch (just like the one in the diagram except momentary instead of latching) then you'll have one set of contacts that are normally open and another set that are normally closed.
I think you'll want to use the ones that are normally open so that when you hit the switch it will close the contacts and engage the feedback loop.
Sounds like you might have used the normally closed contacts and that's why the feedback is on until you hit the switch thus opening the contacts.

Use a multimeter to check which contacts are which. Maybe mark the body of the switch with a sharpie marker or something so it'll be easy to keep it straight even if the switch gets rotated around.

I'm guessing the middle row of contacts (when switch is oriented as it is in the picture) will be common and will make contact with the top or bottom rows as either normally open or normally closed.
I hope that rambling helps and wasn't too confusing.

[Drew Hallenbeck]

I just looked a little closer.

The 3PDT switch is the normal bypass switch and should be latching.
The single pole switch is the one you want to use a momentary switch for.
It's the one that engages/disengages the feedback loop......

[LateCentury]

So, are you saying I would need to add a normal latching 3pdt switch in order to use a momentary switch? That was going to be the next thing I tried. I just didn't want to unwire everything... 

[Drew Hallenbeck]

The three pole latching switch is used for true bypass of the loop. (send and return jacks)

The single pole switch is for engaging the feedback portion of the circuit.

You'll want to wire everything just like it is in the diagram you posted with a latching 3-pole switch and a momentary switch for the feedback. (using the normally open contacts)

I found this diagram a while back and was going to build one of these. I completely forgot about it until I saw your post here. I'm glad you posted this because it's got me thinking about some useful applications.......
I printed the diagram so I can put it to use in the near future.

[zombie_rock123]

Ive seen Beavis' diagram posted before and I always wondered is the pot wired backwards or am I completely not getting it? I would have thought the more resistance the less feedback and so wouldnt the knob being turned up lessen the effect? 

[LateCentury]

Ive seen Beavis' diagram posted before and I always wondered is the pot wired backwards or am I completely not getting it? I would have thought the more resistance the less feedback and so wouldnt the knob being turned up lessen the effect? 

Actually, I was getting greater feedback with the knob turned lower and less feedback when it was turned higher. I thought maybe somehow I had it wired backwards. Would you essentially just swap 1 and 3 to reverse the resistance?

[Jebus]

Yes, that's how you reverse the action of the pot.

[LateCentury]

Ok, so in that diagram, the pot is wired backwards. What about this one? Is this one technically correct? I'm going a 500k pot still, would that make much difference than the the 100k listed? I noticed that the wired is way different too.

[LateCentury]

I just built the above diagram... This also does not work. I'm wondering if just one or two wires are misdirected. I think I've got to find another feedback looper diagram to follow. Does anyone have any they have used and built successfully?

[Drew Hallenbeck]

The above diagran is not a FEEDBACK looper, it's just a true bypass looper with a volume control for the loop.
I took another look at the first diagram you posted and it should work. You may need to flip the connections on lugs 1 & 2 of the pot to get it to work the way you want as far as clockwise vs counter-clockwise rotation.
Give it another look and have another go at it. Remember, the three pole switch is for the bypass and the single pole switch is to activate the feedback.

[LateCentury]

Ah, thanks for pointing that out. So, if I wanted to make the first diagram, (the feedback looper) and eliminate the spdt switch, could i wire the blue wire on lug 1 of the pot directly to the red wire on the middle lug of the 3pdt? And do I connect them to the tip on the out jack?

[Drew Hallenbeck]

Yes, that should work. The only possible drawback is that you'll always have some feedback happening. The amount will depend on where you have the pot set of course but it will be there any time the loop is engaged.
If you want to use this as a set-and-forget with a dedicated effect, eliminating the single pole might not be a bad idea. Adjust amount of feedback to taste and let er rip.
Personally, I'd use a normally open temporary stomp switch for the single pole. That way you can add feedback temporarily. Depending on the effect you have in the loop you can get some really crazy, cool sounding runaway oscillation happening. Then release the switch, feedback stops and it settles back to normal.

[LateCentury]

So frustrated.  I hooked up everything with a normal 3pdt and could not get it to work. The bypass works, but the pot controls that. (what? why?) When the switch is engaged the led comes on but no signal. Triple checked everything. Triple checked everything again.

I disconnected all the wires and threw it in the "@#$% this" box.