Author Topic: Adding buffer to True Bypass looper to defeat popping  (Read 431 times)

slowpogo

Adding buffer to True Bypass looper to defeat popping
« on: June 20, 2022, 12:49:46 PM »
I have four vintage Boss pedals in a row on my board - BF-2, CH-1, PH-2 and DD-3. Four old Boss buffers in a row results in fairly obvious tone suck, so I got a Saturnworks true bypass looper for them.

Problem is, the looper pops loudly with the first use. It usually doesn't pop after that, but I would like to eliminate popping altogether. I haven't tried a pull-down resistor but from what I read those are often not helpful anyway.

Would adding a buffer to the looper (in bypass position) defeat popping? The idea being, I'm replacing bad Boss buffers with a good modern buffer. I am really not precious about things being true bypass, I have several modern buffered pedals on my board already. If putting a good buffer in the looper does the trick -- that's fine with me.

I was thinking of inserting something like this (below) in the Saturnworks. Where would I wire it in to be effective against popping -- between the master input and the switch? or between the switch and the master output?

https://guitarpedalparts.com/products/buffer-pcb?variant=18956583829604&currency=USD&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&gclid=CjwKCAjwtcCVBhA0EiwAT1fY79ZG6spu1cyVAVGLMTx32FB8FYhdSDELCueO765c3WWllYzQQP3xDBoCdzkQAvD_BwE
« Last Edit: June 20, 2022, 12:53:09 PM by slowpogo »

stallik

Re: Adding buffer to True Bypass looper to defeat popping
« Reply #1 on: June 20, 2022, 01:21:24 PM »
Popping is almost always due to a sudden change in voltage.

On some of my pedals, this might be because a cap has to charge  or discharge before equilibrium is achieved. Occasionally, a pull down resistor might help force such a cap to be in a better state when I next switch the pedal on. Or maybe not. Sometimes pedal ventriloquism comes into play where something in one pedal has no effect on that pedal popping but, by god, does it mess with another in the chain! And that one was totally silent before.

Iíve seen the blame layed with LEDís, caps, low quality switches, duff wiring and the altitude of the moon but Iíve not yet come across a buffer circuit as a cure all.

If your circuit is only popping first time you switch it, Iíd imagine that a cap is charging and, once charged, everything goes quiet. I have such a pedal. But it only behaves that way when 2 other specific pedals are in the same chain.

Your boss pedals use a switching circuit that may mute the signal (very briefly) while the switching occurs. Hence, no pop. They may be buffered bypass but itís not the buffer that makes it quiet
« Last Edit: June 20, 2022, 01:34:08 PM by stallik »
Insanity: doing the same thing over and over again and expecting different results. Albert Einstein

slowpogo

Re: Adding buffer to True Bypass looper to defeat popping
« Reply #2 on: June 20, 2022, 02:21:08 PM »
Thanks for that, very informative.

These pedals are from 1982-1990. They work fine and sound great but I imagine not all the electrolytics are in the best shape after all this time.

If I can isolate which pedal(s) is popping - might re-capping the electrolytics do the trick? I realize this might subtly change the sound, etc but might be worth it, and probably not a terrible idea anyway for a 40YO electronic device

antonis

Re: Adding buffer to True Bypass looper to defeat popping
« Reply #3 on: June 20, 2022, 02:42:56 PM »
Are those pedas daisy-chained or powered from individual supplies..??
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stallik

Re: Adding buffer to True Bypass looper to defeat popping
« Reply #4 on: June 20, 2022, 03:25:46 PM »
Thanks for that, very informative.
Actually, I donít think Iíve been informative at all. Popping issues can be very difficult to correctly diagnose.
As Antonis rightly asks, your power supply can have a huge bearing on this
Also, if your looper pedal is powered (even just for LEDís) this might be a source for the popping
Insanity: doing the same thing over and over again and expecting different results. Albert Einstein

slowpogo

Re: Adding buffer to True Bypass looper to defeat popping
« Reply #5 on: June 20, 2022, 06:48:26 PM »
Are those pedas daisy-chained or powered from individual supplies..??

I'm using a 1Spot Pro CS12. Two of the Boss are the old 12V type and those are daisy chained to one output on the CS12, the other two are 9V with their own connections.

My board has enough pedals that I need to daisy chain in a few places, but it's never caused any issues that I know of. I'll try powering all the Boss individually and see if that helps.

PRR

Re: Adding buffer to True Bypass looper to defeat popping
« Reply #6 on: June 20, 2022, 07:03:09 PM »
> I haven't tried a pull-down resistor but from what I read

Who are you going to believe? Your own test, or "others"?

Popping is often like an onion. You peel off one layer and there is another layer. No single technique cures all cases. More often it is like stripping the walls in an old bathroom. (paint, paint, paper, wallboard, tile.....)
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slowpogo

Re: Adding buffer to True Bypass looper to defeat popping
« Reply #7 on: June 20, 2022, 07:15:46 PM »

Who are you going to believe? Your own test, or "others"?


oh brother, this thread is a mistake lol. I may try the pulldown, but it seemed like a low probability solution from the research I did. I don't know, I'll try some stuff. Thanks for anyone who contributed

idy

Re: Adding buffer to True Bypass looper to defeat popping
« Reply #8 on: June 20, 2022, 07:56:47 PM »
A contraire! Pulldown is the easiest thing to try and works for lots of thing, they are standard engineering and can be tacked on without disturbing a PCB, and removed if not needed. They may be necessary on input and output. Old style unbuffered pedals with the volume control at the end of the circuit you don't need them for output, but buffers, you might.
I also reccommend doing a little sleuthing: Can you isolate the problem to a single pedal? Will any single pedal do this in the looper by itself? Do any of your pedals (including any before or after the looper) have any DC on input or output? That would be a good place to start. Even amps sometimes send DC back up the cable.

If you discover leaking DC then you start to think about recapping, unless that sounds like fun to you. People find fun in funny places.

Rob Strand

Re: Adding buffer to True Bypass looper to defeat popping
« Reply #9 on: June 20, 2022, 10:01:50 PM »
Quote
I have four vintage Boss pedals in a row on my board - BF-2, CH-1, PH-2 and DD-3. Four old Boss buffers in a row results in fairly obvious tone suck, so I got a Saturnworks true bypass looper for them.
The Saturnworks claims to be a true bypass so you would assume it could leave the input of the first pedal floating.

While Boss pedals are pop-less there is an assumption that there is an input source connected to their input socket.

When you wrap a true-bypass switcher around the Boss pedals it might not be pop-less as the true-bypass wrapper could leave the input of the first pedal floating.

If that's the only problem then adding say 2.2M to ground at the input of the first Boss pedal in the chain should at least prevent the pops due to the input of the first Boss pedal input floating.   The resistor needs to be at the Boss pedal input not the input of the switcher.

It might not be the only problem but as far as a chain of Boss pedals go it's probably the only source of popping that can be blamed on the pedal part.
« Last Edit: June 22, 2022, 03:41:12 AM by Rob Strand »
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PRR

Re: Adding buffer to True Bypass looper to defeat popping
« Reply #10 on: June 21, 2022, 01:19:02 AM »
oh brother, this thread is a mistake lol.

No, my mistake. I'll butt out.
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Re: Adding buffer to True Bypass looper to defeat popping
« Reply #11 on: June 21, 2022, 05:00:08 AM »
If that's the only problem then adding say 2.2M to ground at the input of the first Boss pedal in the chain should at least prevent the pops due to the input of the first Boss pedal input floating.   The resistor needs to be at the Boss pedal input not the input of the switcher.
Any reason why that can't be on the send jack of the first loop, Rob?

Rob Strand

Re: Adding buffer to True Bypass looper to defeat popping
« Reply #12 on: June 21, 2022, 05:49:59 AM »
Quote
Any reason why that can't be on the send jack of the first loop, Rob?
That's fine, it's the same thing.  I used "Boss input" throughout to be clear about the cause.

Also, I've only explain one possible scenario.   The Saturnworks could short the effect input to ground.  That would mean there's already a path to ground and it shouldn't pop.   If it did it might point to an issue with the signal source feeding into the Saturnworks not having a path to ground on its output.

I notice one version has an LED.   Even that could cause popping.  However, I don't think it's that.  "Pop once" issues tend to point to input and/or output caps not having paths to ground.
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