True bypass looper question

[mindtwist07]

I'm just wondering, Is it possible to create a true bypass looper with push button on and off switch with two tips instead of using a 3dpt switch?


Thanks

[Mark Hammer]

Traditionally, that's all it really required.  It wasn't until people started cluttering their pedalboards and started wanting status LEDs so they could keep track of what was and wasn't on that 3PDTs became necessary for doing the bypass AND status indication.

But if you know that something is on or off (and most fuzzes would likely fit into this category, as would tremolos and other not-so-subtle effects) 2 sets of contacts is all you need to do the job.

Some Loop selectors are set up so that you have a choice of using them powered - with status LED - or unpowered (bypass only).

[vendettav]

well a DPDT truebypass is certainly doable. Either without and LED or with a MIllenium bypass

[mindtwist07]

@Mark Hammer

           I see, Is there any diagram on the net available for this kind of idea? with or without power? and the same time using just a push button switch. I'm just a beginner with electronics I' m not that familiar with certain technical words or jargon's yet. I would like to check an cheaper alternative for the 3dpt switch.


@vendettav

           yeah yeah, I saw that on the beavisaudio site. I just want to try a simple push button switch check if that might work..rather than a dpdt or a 3dpt switch for a true bypass looper pedal.

[swinginguitar]

Geofex has comprehensive articles on doing it with momentary switches...in short, a couple of ICs toggle relays and associated LEDs.

I'm in the early stages of making one that uses a PIC to do it - footswitch toggles the state of a pin which in turn drives the relay/LED (will work with steroe loops this way)

[Mark Hammer]

@Mark Hammer
           I see, Is there any diagram on the net available for this kind of idea? with or without power? and the same time using just a push button switch. I'm just a beginner with electronics I' m not that familiar with certain technical words or jargon's yet. I would like to check an cheaper alternative for the 3dpt switch.

Here's a useful page: http://www.muzique.com/lab/tsbuff.htm  The document shows how to use a DPDT switch for bypass (which is all a loop selector does) with one effect.  It also shows how to make use of the buffer that might already exist in a pedal so that only ONE set of contacts of a DPDT is needed to bypass, leaving the 2nd set of contacts free to provide a status indicator.  A 3PDT used for TB-with-indicator would normally have the wiring you see in Fig 1, plus the wiring for the LED you see in Fig 2.

If you wired up a 3PDT for loop selection as per the usual way you see illustrated, and the power went out or was removed, what you would be left with is everything that goes on in the first 2 sets of contacts, which is precisely what you see in Fig 1.

Make sense?