Author Topic: BSIAB audible footswitch POP!!  (Read 380 times)

SpikeVelvet

BSIAB audible footswitch POP!!
« on: April 15, 2019, 10:35:33 PM »
What can be done to silence the audible footswitch pop? I built a BSIAB from the GGG kit and I was under the impression that R1 was the pull down resistor and that it was there to keep the footswitch noise under control. Is there anything else I can do?

deadastronaut

Re: BSIAB audible footswitch POP!!
« Reply #1 on: April 16, 2019, 05:01:23 AM »
try input and output ground in bypass wiring on your 3pdt.

https://www.diystompboxes.com/smfforum/index.php?topic=104109.msg931319#msg931319
http://www.youtube.com/user/100roberthenry
https://deadastronaut.wixsite.com/effects

chasm reverb/tremshifter/faze filter/abductor II delay/timestream reverb/dreamtime delay/skinwalker hi gain dist/black triangle OD/ nano drums/space patrol fuzz//

antonis

Re: BSIAB audible footswitch POP!!
« Reply #2 on: April 16, 2019, 05:53:08 AM »
And what about LED-pop, all time lazy Rob..??  :icon_redface:

Can't follow your signature changes, Stephen..!!
but I like what follows:
"put the coffee down, Antonis, and nobody will get hurt."
"Arggg, Jim ...."

deadastronaut

Re: BSIAB audible footswitch POP!!
« Reply #3 on: April 16, 2019, 08:10:01 AM »
indeed...that as well... 8)
http://www.youtube.com/user/100roberthenry
https://deadastronaut.wixsite.com/effects

chasm reverb/tremshifter/faze filter/abductor II delay/timestream reverb/dreamtime delay/skinwalker hi gain dist/black triangle OD/ nano drums/space patrol fuzz//

SpikeVelvet

Re: BSIAB audible footswitch POP!!
« Reply #4 on: April 16, 2019, 10:17:19 PM »
Thanks for the help!! I wired that up and it improved it. It's not silent but it's greatly reduced.

SpikeVelvet

Re: BSIAB audible footswitch POP!!
« Reply #5 on: April 17, 2019, 10:04:00 AM »
Quick question....would a bigger CLR or a bigger capacitor reduce the pop even more? The BSIAB uses a 1k CLR and I used a 10uF cap to ground. If I go to 4k7 and 47uF would that reduce the pop even more?

Thanks

MrStab

Re: BSIAB audible footswitch POP!!
« Reply #6 on: April 17, 2019, 10:14:56 AM »
yknow what i find helps? a really bright LED - 3,000mcd or so - and a 10k+ resistor. then you're only dealing with less than 1mA of stray current, and you're wasting less power in the process.

SpikeVelvet

Re: BSIAB audible footswitch POP!!
« Reply #7 on: April 17, 2019, 12:35:30 PM »
Is there some math behind this you could reveal?

MrStab

Re: BSIAB audible footswitch POP!!
« Reply #8 on: April 17, 2019, 01:08:35 PM »
just Ohm's Law. 9V / 10,000 ohm = 0.0009A, or 900 microamps. maybe try switching the 4k7 in Antonis' suggestion to 10k? it won't completely eliminate pop, but it'll help. 4k7 is fairly high already, though.

you can go higher than 10k, and you can get brighter LEDs. ultra-brightness is a luxury of the modern age.

does the pop still happen if you disconnect the LED altogether...? because the high-gain BSIAB circuit or (rarely) switch microphonics could be contributing to the pop.

SpikeVelvet

Re: BSIAB audible footswitch POP!!
« Reply #9 on: April 17, 2019, 02:13:15 PM »
Thanks MrStab,

Currently there is 1k in the circuit, which GGG uses as the default. Swapping a 4k7 or a 10k is an easy fix. I'll try that.

http://www.generalguitargadgets.com/pdf/ggg_bsiab2_sc.pdf

MrStab

Re: BSIAB audible footswitch POP!!
« Reply #10 on: April 17, 2019, 11:00:29 PM »
no problem! change the LED too, though, if it's not super or ultra-bright. just as an example, here's what i usually use with 10k's:

https://www.rapidonline.com/kingbright-l-7113src-j4-5mm-super-bright-red-led-3500mcd-55-9212

antonis

Re: BSIAB audible footswitch POP!!
« Reply #11 on: April 18, 2019, 05:50:59 AM »
Well said above  :icon_wink: but are we sure popping is due to LED activation..??
(meaning, are everything OK with LED not powered..??)

<Is there some math behind this you could reveal?>

Additional to what Mr. Stab well said.. :icon_wink:
4k7 resistor & 10μF capacitor form a low pass filter of about 3.4Hz cut-off frequency with also a time delay of about 200ms (for 4.5 X RC) - you might (or might not..) notice that delay on LED activation..  :icon_wink:
« Last Edit: April 18, 2019, 05:53:15 AM by antonis »
Can't follow your signature changes, Stephen..!!
but I like what follows:
"put the coffee down, Antonis, and nobody will get hurt."
"Arggg, Jim ...."

Ice-9

Re: BSIAB audible footswitch POP!!
« Reply #12 on: April 18, 2019, 04:26:18 PM »
As a test to find the cause of the pop you can remove the LED altogether, this will tell you if the pop is coming from the LED or other source.
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !
Do me a lemon, that a poor IQ for a glass of water.

SpikeVelvet

Re: BSIAB audible footswitch POP!!
« Reply #13 on: April 18, 2019, 09:09:08 PM »
Thanks Ice9 I will try that because I tried a 10k and it did not improve the popping

willienillie

Re: BSIAB audible footswitch POP!!
« Reply #14 on: April 19, 2019, 02:14:46 AM »
I recently experienced a very noticable increase in switch popping with ALL of my pedals.  I measured DC across the input of my amp, after it was on for a while it got as high as 80mV.  There was a nearly new JJ 12AX7 in V1.  I swapped in an old Sylvania and the problem was cured.

SpikeVelvet

Re: BSIAB audible footswitch POP!!
« Reply #15 on: April 19, 2019, 07:27:18 AM »
Thanks Willienillie,

I'm not experiencing a pop from my other pedals so I will keep that in mind. My other DIY pedal is a BYOC Silver Pony and it has an audible acoustic "click" sound you can hear in the room but NOT in the signal path. The BSIAB definitely produces a POP that is in the signal path.