Momentary & Latching True Bypass Effects Looper?

[Mandobird]

Trying to make a true bypass looper with a momentary switch and a latching to control a single loop, like these:

http://www.brightonion.co.uk/products/Momentary-Looper.html
http://www.loop-master.com/product_info.php?cPath=32&products_id=253

Originally was going to wire it as per a normal looper, with a momentary DPDT and 3PDT switch like this:



Obviously this doesn't work as when one's off the send is grounded and therefore pressing the other switch does nothing.  I tried wiring the ground to only the bottom left lug of the 3PDT but the DPDT wouldn't work, and vice versa when wired in reverse.

Anyone know how to wire it, or built one before?  I could just not have the send grounded when the signal's bypassing the loop, but loopers always have the send grounded so I'm assuming it needs to be done somehow.  Is a 4PDT needed maybe?  Not fussed about a feedback loop happening when both switches are engaged (it rather appeals actually).  Thanks.

[GGBB]

I think this should work, but you will need a 3PDT momentary switch instead of DPDT.  If you don't care about grounding the send jack when bypassed you can use the DPDT (drop the 3rd column).  There's no feedback loop with this one.



EDIT: Added option to turn on LED with momentary switch

[Gurner]

reminds me of a pink floyd album....

A momentary latching reason?

[I'll get me coat]

[Mandobird]

Thanks so much for that GGBB, I'll try it if I can get a momentary 3PDT.

A momentary latching reason?

Nice - I was having a boring day until I read that.

[Mark Hammer]

This is one of the reasons why I like Craig Anderton's CMOS electronic EPFM switches.  Yes, they're not "straight wire true bypass", but they can be wired as latching or non-latching by simply paralleling a momentary and latching SPST footswitch.

Non-latching relays can also be used for your purposes.  If actuated with a momentary non-latching footswitch, they revert back when you lift your foot up.  If you actuate with a latching footswitch, they stay where they are until you press again.

If you ask me, there are a bunch of pedal categories that ought to come with latching and non-latching switches, so they can be used a riff at a time.  Ring modulators are a perfect example.  Exactly how many players use them for more than a riff at a time?

[mafew129]

Has anyone tried this? Does this layout work?

[slacker]

The one by GGBB will work. The momentary only switches from bypass to effect on, it doesn't do anything if the effect is already on.

[blackieNYC]

If you need an LED to tell you you've stepped on a momentary switch, you should go barefoot - and build wackier sounding pedals!
But seriously folks, I've picked up the little DPDT relay board kits (one from AMZ, one from small bear) in order to have a momentary true bypass switch activated by an SPST momentary switch - the only type that is clickless.  Clicklessness (?) isn't always essential of course, but with a stutter-type action, it feels a little quicker and easier.

More Momentary Fun, like Mark said:  New York City real estate, where every cubic centimeter counts, affects my pedal builds.  Top mount jacks, etc.  I've haven't any plans for an expression pedal any time soon.  But I've had this idea to incorporate momentary switches -  TB loops like yours- and another idea to get a cheap and easy expression pedal from a momentary switch.  I've got a momentary switch to max out the modulation speed on one thing, and another I want is to have a momentary switch insert a different resistor in place of the Delay Time pot on a 2399 delay.  Or maybe the feedback could be maxed out momentarily, eh?  Maybe to alter the center frequency of a fixed-wah type EQ.  I think sometimes I will encounter an unacceptable thump if the switch is inserted into certain DC circuits, definitely a breadboard venture.
I always listen to Mark - except when he goes dissin' ring modulators, which should be left on at all times....

[Mandobird]

The layout is fine, built one and works perfectly.  The momentary 3PDTs I've used have a really soft click, maybe even slightly softer than a lot of momentary SPDTs.  I'd actually go clickless with a relay or CMOS for this set-up, as the feel of a soft touch footswitch lends itself better to very quick and fluid momentary taps IMO - but it comes down to personal preference really (and relays/CMOS naturally entail more work).

[Eemukis]

I tried this build but I can't get the bypassed signal. Both the latched and momentary switches work as they should. Any ideas?

[jimilee]

I tried this build but I can't get the bypassed signal. Both the latched and momentary switches work as they should. Any ideas?

According to the first diagram, it won't work and it grounds the bypass signal.

[blackieNYC]

Check out the diagram and the paragraph explaining the "conditions" I want in this looper idea. 
http://www.diystompboxes.com/smfforum/index.php?topic=110713.msg1016643#msg1016643

[GGBB]

I tried this build but I can't get the bypassed signal. Both the latched and momentary switches work as they should. Any ideas?

According to the first diagram, it won't work and it grounds the bypass signal.

Eemukis - which one did you build?  The last diagram (mine) works fine as verified by Mandobird in the post before yours.

[blackieNYC]

This is a nifty idea that suits all possibilities of single fx loop wiring.  Sounds more confusing than it really is.  This will let you listen to the input and momentarily insert the loop, listen to the loop and momentarily insert the input, latch the input, latch the loop, and true bypass.  Two stomps and one extra toggle.  Read the whole thread if you think you want to do this.  You can PM me.  I'm going to wire this up very soon.

OK, I might have it now. 
MOMENTARY OR LATCHING TRUE BYPASS LOOPER AND MOMENTARY STUTTER/MUTE SWITCH

Once again, the conditions:

I want the output to be selectable to achieve each of these functions
A. a momentary insert of a send/return loop, and when the momentary stomp is at rest - the input.
B. a bypass of the input to the output - which condition A provides when the stomp is at rest.
C. the loop return to the output, when the momentary is at rest.
D. a stutter of the input when the momentary is stomped, and muted when at rest.
E. a stutter of the loop return when stomped, muted when at rest.

SW1 is a 3PDT latching stompswitch, SW2 is a DPDT toggle, SW3 is a DPDT momentary stompswitch.

[GGBB]

This is a nifty idea that suits all possibilities of single fx loop wiring.  Sounds more confusing than it really is.  This will let you listen to the input and momentarily insert the loop, listen to the loop and momentarily insert the input, latch the input, latch the loop, and true bypass.  Two stomps and one extra toggle.  Read the whole thread if you think you want to do this.  You can PM me.  I'm going to wire this up very soon.

No status LED(s), right?

[Eemukis]

Yeah I used ggbb's diagram. Maybe I have cold connection somewhere. I'll check it later today. I was just making sure others had built it successfully.
Thanks guys

[GGBB]

Yeah I used ggbb's diagram. Maybe I have cold connection somewhere. I'll check it later today. I was just making sure others had built it successfully.
Thanks guys

Based on your report that on and momentary-on work fine but bypass doesn't, check the jumper wire connection between bottom row left and center (in the pic) on the momentary switch.

[blackieNYC]

GGBB-  No LED.  depending on the status of the two fixed switches, the output signal will be
Mom off: input, mom on: loop.
Mom off: mute, mom on: loop
Mom off: loop, mom on: input
Mom off: mute, mom on: input
I think of each of these as a mode in which you would do one song.
This is more than what the OP is looking for, I just started thinking "I wonder if I could add a stutter switch.."
It's the only way to do this with these few resources. If you use a latching 4pst instead of a 3pst you could add LED status there, and you could add a pole to the other latching switch for an LED as well.  But there's a lot of combinations here that you would still need to decode.  If you look at the truth table in the other thread, you'll see what these LED s would indicate, and it would be only slightly helpful.
The latching 3p2t could be a toggle. A large visible one if you like.  Since there is a momentary switch here, I don't see the latching switch as much of a timely stomp in the middle of a song - more of a more switch, defining the action of the momentary.  Like a pot, you set it for that song beforehand, and then rely on the one stomp during the song. The LED would be great, and you could do it, but even if all the switches had one, I feel I would still need to listen to see where I'm at.  Or tape the truth table to the back of the guitar, next to the lyrics.  I plan to just learn how to do it.  My song will be played in input mode with a momentary loop to kick in, or it will be a stutter switch with the momentary kicking in the input.  Or the loop.  Or I will play the song with all the wacky sounds in the loop and step on the momentary to kick in a brief clean part.
I guess I got used to my MXR dist +, with no LED.
As for the momentary having an LED, that seems kind of unnecessary, but I think you mean the other switches.

I do plan to make the momentary a relay for quieter and lighter touch switching, but I personally would find this very useful without relays.   All possible combinations of Mute, Input, and Loop are there, except those that would offer a momentary mute, which I don't have a need for in designing a looper.  Also, one condition - a fairly unusual one where you are playing through the full loop and want to momentarily kick in a simpler sound - would have the straight input sound connected to both output and loop input.  My pedals are designed properly enough that this isn't a problem, but I must divulge this weak spot in the design.  But improvements in the performance of this looper would require more switch poles and even another switch.  Then the truth table goes to 16 options and the LEDS aren't going to help me with that. 

{edit: I just wired and tested it and it works. Until now I was only asking people to look at the wiring and double check the truth table}

[Eemukis]

Ok. So I got it working by disconnecting the jumper between the top center and bottom right lugs on the momentary. Am I missing something?

[GGBB]

What do you have connected to what (in, out, send, return)? That jumper merely grounds the send (the loop input) when in bypass - it is lifted when either switch is on.