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Discussion Starter #1
Over my years of trying numerous pedals there have been a handful that suffer from this malady. I purchased one recently and I've tried everything outside of taking it apart and mod'ing it or selling it, to fix it. I've changed cables, changed it's position in the chain, tried it just by itself, all to no avail. I can obviously, I think, get around the issue by using a switcher but are there any other options? I really like the pedal and would like to keep it. Tried to contact the company but no luck so far.

Also tried to buy a loop master but the seller seems to have disappeared.
 

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I found the Topanga reverb did the same. Turns out there's a switch inside to go to buffer mode... and that's their resolution for the pop. :(
 

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Many times, though not ALWAYS, the pop is not from that pedal, but from what comes after it. I refer to this as "pedal ventriloquism", since one pedal appears to "throw its voice" to another.

Many pedals that use electronic switching internally have an unterminated input capacitor. Assuming nothing that gets plugged into it will ever be disconnected mid-tune/mid-set, that strategy works just fine, and minimizes loading effects. The problem arises when such pedals are preceded by true bypass devices, whether a loop-selector or another pedal. When you hit those stompswitches, that input capacitor in the e-switched pedal is momentarily disconnected then reconnected, producing the pop. One characteristic that can identify such a scenario is that if you stop playing for a bit, and keeping pressing the TB stompswitch on and off a few times, the pop will eventually disappear as the errant input cap gets drained off with each reconnection.

It's not the ONLY potential source of switch-popping, but as more and more players combine lots of different brands and kinds of pedals on their board - big-name, boutique, digital, analog, etc. - the odds of a TB-followed-by-e-switched pedal scenario increase.

The solution is to simply stick a 1M-2.2M resistor between the hot and ground lugs of the e-switched pedal to provide an uninterruptible drain/bleedoff path for that pedal's input capacitor that will be unaffected by whatever precedes it. That range of values should have no discernible impact on tone.
 

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Discussion Starter #5 (Edited)
Many times, though not ALWAYS, the pop is not from that pedal, but from what comes after it. I refer to this as "pedal ventriloquism", since one pedal appears to "throw its voice" to another.

Yep, that's why I tried all the steps listed in the OP. Including this pedal stand alone.

One characteristic that can identify such a scenario is that if you stop playing for a bit, and keeping pressing the TB stomp switch on and off a few times, the pop will eventually disappear as the errant input cap gets drained off with each re-connection.

First thing I tried with no success.

The solution is to simply stick a 1M-2.2M resistor between the hot and ground lugs of the e-switched pedal to provide an uninterruptible drain/bleed off path for that pedal's input capacitor that will be unaffected by whatever precedes it. That range of values should have no discernible impact on tone.

Could you be a little more specific please, electricity is a black art :) Would this be done on the switch or across the input and output jacks? I can live with the fact this is likely a very stupid question :)
 

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Okey dokey. I can't see much technical info that would shed any light, and haven't found any gutshots. From the outside, the stompswitch would appear to be the usual hard click type. Not unless they've located a source of soft-touch switches to actuate a relay, and they merely look like the hard-click type.

Another possibility is the amp itself. Is it possible the amp itself has a "hanging input cap"?

Alternatively, just how bright is the status LED on the pedal? Sometimes an LED can draw enough current to create a pop. That is, the audio circuit is fine on its own, but the turning on of the LED causes an audible artifact. One way to identify if that's the culprit is to simply desolder one of the LED leads from the stompswitch. If the pop disappears when the LED is out of circuit, then that subcircuit is the culprit.

Jack Orman has some good ideas about curing it here: AMZ - LED Popping
 

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Discussion Starter #8
Okey dokey. I can't see much technical info that would shed any light, and haven't found any gutshots. From the outside, the stompswitch would appear to be the usual hard click type. Not unless they've located a source of soft-touch switches to actuate a relay, and they merely look like the hard-click type.

Another possibility is the amp itself. Is it possible the amp itself has a "hanging input cap"?

Alternatively, just how bright is the status LED on the pedal? Sometimes an LED can draw enough current to create a pop. That is, the audio circuit is fine on its own, but the turning on of the LED causes an audible artifact. One way to identify if that's the culprit is to simply desolder one of the LED leads from the stompswitch. If the pop disappears when the LED is out of circuit, then that subcircuit is the culprit.

Jack Orman has some good ideas about curing it here: AMZ - LED Popping
I'll post some gut shots and try it with a couple of amps to rule that out. I "think" I already did that but I'll make sure. First up is lunch however :)

Thanks for taking the time.
 

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No problem. No rush. I'm headed out in 5 minutes to meet up with my sister at CityFolk to see MonkeyJunk and Whitehorse today. Won't be back on line until later in the evening.

Honestly, you try and get some quality soldering time in and everything gets in the way!
 

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Discussion Starter #11 (Edited)
To quote Ian Anderson "Nothing Is Easy", including getting good pics. looks like there is a small switch pcb board mounted to the switch. Hopefully you can make this out.

There is a ribbon cable connecting the main board to the switch board.

The pedal only "pops" when engaging the pedal, not disengaging.

Tried 2 other amps, same issue.

With either volume or gain on pedal rolled completely off there is no pop.



 

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Back from the festival. Man oh man, Luke Doucet knows what a Gretsch is for.

But, on the topic. Thanks for the gutshot Dave. It's clearly a standard 3PDT switch, used exactly as I might use it. Don't make too much of the little board it comes on. A number of places sell those little boards, as a way of easing the installation of switches, using ribbon cable.

Officially, those switches are break-before-make, which means there will always be a brief moment where the pedal circuit, and switch, is disconnected from what comes before and after it.

Assuming the source of the pop is not within the pedal itself, the question for me then becomes "Is there anything it might be plugged into or that plugs into it, that might have an unterminated capacitor?". Again, that assumes that the PAL 959 itself has its input and output capacitors properly terminated with a resistor, so they can bleed off any residual charge to ground.

The fact that the pop occurs when you engage it, but not disengaging, and that it seems independent of the amp used, suggest that the pedal itself might have a "floating" input cap. The maker/s seem to have gone to a fair amount of trouble to make a decent product, so I'm reluctant to assume they have such a floating cap. That said, if you have the gear and confidence, you can try the following.

There are a few ways to wire up a 3PDT switch for true bypass, but the most commonly used is this one below.


- use a meter to identify which of the switch pins/lugs takes the signal from the input jack, and which two switch lugs are directly connected to each other as per the "link". That will help you to identify which switch lug is the one that goes to the input of the circuit without having to take the whole damn thing apart (and chase the stupid washer that fell out and rolled under the bench). If you can, temporarily solder a 1M resistor (or even 470k, if push comes to shove) from that circuit-input lug to ground. IF it was an unterminated input that is causing the popping, then that would cure it. And if the problem lies elsewhere, then you can simply remove that added resistor, and go back to square one. Naturally, if you have wires with alligator clips, then I'm sure you'd prefer to "install" the added resistor with those, and leave the board pristine.

I'll await your feedback, and we can take it from there.
 

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Discussion Starter #14 (Edited)
Thanks for the nicely detailed info Mark. I'm just looking for continuity to identify the circuit? I'll need to dig around, or buy, a resister so it may be awhile before i get to it. I assume I'm looking for something like this?

As a matter of interest what value is there in determining the "link" if all I'm doing is taking something from the input connection on the switch to ground?

 

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Yup, that's what it would look like. I don't know how available components are where you live (can't rely on Radio Shack anymore), and it makes no sense to pay shipping for a single resistor. HOWEVER, there is so much e-waste tossed out these days, and 1M is such a standard value, that if you don't already have one in your possession, pretty much anything left out at the curb by someone should be able to provide something you can "liberate".

And yes, as a minimally intrusive, non-destructive, first step to identify if the pedal itself contributes to the problem by virtue of the circuit, you ARE looking for tell-tale aspects of continuity (I hope your meter has a buzzer when that happens) that can let you know if the input is unterminated. The alternative is to take the whole damn thing apart and visually trace out the connections from the switch to the board. My suggestion is intended to save you from that misery. I hope it works. :)
 

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Discussion Starter #16
Yup, that's what it would look like. I don't know how available components are where you live (can't rely on Radio Shack anymore), and it makes no sense to pay shipping for a single resistor. HOWEVER, there is so much e-waste tossed out these days, and 1M is such a standard value, that if you don't already have one in your possession, pretty much anything left out at the curb by someone should be able to provide something you can "liberate".

And yes, as a minimally intrusive, non-destructive, first step to identify if the pedal itself contributes to the problem by virtue of the circuit, you ARE looking for tell-tale aspects of continuity (I hope your meter has a buzzer when that happens) that can let you know if the input is unterminated. The alternative is to take the whole damn thing apart and visually trace out the connections from the switch to the board. My suggestion is intended to save you from that misery. I hope it works. :)
My meter does in fact buzz :)

I have an old pedal that I will use to try and salvage a resistor. It was custom made for me many years ago by a guy on TGP but never did sound all that great, LOL.
 

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Discussion Starter #19 (Edited)
Yup, that's what it would look like. I don't know how available components are where you live (can't rely on Radio Shack anymore), and it makes no sense to pay shipping for a single resistor. HOWEVER, there is so much e-waste tossed out these days, and 1M is such a standard value, that if you don't already have one in your possession, pretty much anything left out at the curb by someone should be able to provide something you can "liberate".

And yes, as a minimally intrusive, non-destructive, first step to identify if the pedal itself contributes to the problem by virtue of the circuit, you ARE looking for tell-tale aspects of continuity (I hope your meter has a buzzer when that happens) that can let you know if the input is unterminated. The alternative is to take the whole damn thing apart and visually trace out the connections from the switch to the board. My suggestion is intended to save you from that misery. I hope it works. :)
OK let's see if any of this will work ;-)

I found a loose resister that reads 0.473M on my meter. Colour bands are somewhat faint but appear to be Yellow, Purple, Yellow, Gold. It has nice long legs on it, similar to those in @greco 's post above. Will that work?

Running a continuity check from the positive of the input jack it looks like lower right corner terminal is the switch connection with the upper left and the one below it being linked. I get a "buzz" when touching any of those with the meter.

If all of that works for you I assume I run the resister from the lower right switch terminal to ground somewhere? Any preference on the ground connection? Output jack ground for instance?

This fuzzy image is the orientation referenced. Input jack on the left. (which is a stereo jack for some reason)


 
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