Ok, i've been busting my ass for the past week, re-wiring my overdrive (byoc ts808 board) 10 different times to eliminate a switch pop. With an LED, there is a loud pronounced pop.
-I've tried the old bypass here http://www.diystompboxes.com/beginner/circswled.jpg , pops
-then instead of switching the power to the LED, i switched the LED to ground. effect works, still popped
-then i tried the input grounding style, like most new GGG projects, the BYOC kit wiring, the OLC kit wiring (http://www.olcircuits.com/support.html , go to doc # 2), still pops
Then i tried the two different styles of wiring, but without the LED. Not as pronounced of a pop, but more of a click.
Discouraged, i put down the soldering iron and plugged my guitar into my tuner (korg dt-10bk) and....i'll be damned if i heard a little click out of that too! so i got some other non-diy pedals. A mxr phase 90 (not vintage), digitech digiverb, and a CMAT mods ts808. The cmat pedal obviously had the same issue as my overdrive. But the 2 commercial pedals clicked too! Not as loudly, but you could hear an audible click!
Now i just have one question. WHAT THE HELL?!?!!?
Here's the important information. Amp is a fender prosonic head into a 212 cabinet. Cables to and from pedal are either cheap 15foot cables i bought from guitar center, or george l's patch cables. The power supply is a godlyke Powerall.
What do you guys think it could be. Also, i had the same issue at my gig last night. The overdrive popped, and i had the input grounded style wiring.
AH!
thanks,
murad
was is so loud that anyone would be like "what the flying pig was that?!" or was it just "only i, the guitar player, will notice."
There are only two reasons effects pop when switched.
1. You're switching between two different DC levels. Find where the DC is not blocked and block it, or eliminate the leak.
2. You are coupling in the sudden change in power use when an effect is switched on or off through power, ground, or parasitic capacitance.
Number 1 is much more common.
Is your amp putting a DC level on its input? So that when you switch to a pedal whose output was at zero volts, there is a pop as the effect output adjusts to the non zero DC level? You could tell quick by sticking a cord into the amp and testing the DC volts between tip and sleeve.
Quote from: thebattleofmidway on July 31, 2007, 12:11:01 AM
was is so loud that anyone would be like "what the flying pig was that?!" or was it just "only i, the guitar player, will notice."
The TB pedals pop loud enough for people to notice. The buffered pedals click enough to bug me and tell me "something is not right"
Quote from: R.G. on July 31, 2007, 12:20:27 AM
There are only two reasons effects pop when switched.
1. You're switching between two different DC levels. Find where the DC is not blocked and block it, or eliminate the leak.
2. You are coupling in the sudden change in power use when an effect is switched on or off through power, ground, or parasitic capacitance.
Number 1 is much more common.
When you say find were the DC is not blocked/leaking, where would i be searching for that? In the pedal? In my Powersupply? Its popping in ALL my true bypass pedals, so i'm thinking i got a serious issue! Also, if I need to poke around my pedal, how would i do that? And how would i block the leak?
Quote from: Processaurus on July 31, 2007, 04:25:41 AM
Is your amp putting a DC level on its input? So that when you switch to a pedal whose output was at zero volts, there is a pop as the effect output adjusts to the non zero DC level? You could tell quick by sticking a cord into the amp and testing the DC volts between tip and sleeve.
I turned on my amp, stuck it into a mono jack, and busted out my multimeter. I was getting .2 mv, totally negligible cause my DMM reads more than that when it's even just idling.
Think it could be the powersupply that needs to be replaced?
One of the somewhat counter-intuitive side-effects of the current true-bypass frenzy/cult/zeitgeist is that if you have a bunch of TB pedals in series and one of them somewhere has a "hanging cap", switching another pedal somewhere else can still produce a pop. Imagine we have 5 pedals in a row and pedal 1 has a hanging cap on its output. If all the otherpedals are off and I switch any single one of them on, there will be a brief instant where that cap is disconnected and then reconnected. Of course, since the pop is occurring when I'm switching one of the OTHER pedals, I assume that the problem is with them, when it it really isn't.
I might also point out that Boss pedals have a hanging cap on their input since they assume all switching will be done internal to the circuit, so the cap will never be left hanging or unconnected once you plug in. You get used to hearing a slight pop at that point, but you never hear a pop thereafter when you engage and bypass, so you figure everything is copasetic. But it isn't. The irony is that if you try and get Boss and homebrew TB pedals to play nice with each other, each time you engage or disengage the TB pedal just ahead of the Boss pedal (or even several ahead if you have, say, a couple of homebrew distortions followed by a Boss Chorus), that input cap is momentarily disconnected then reconnected. It's not a BIG cap (Usually .01uf, right?), so the pop shouldn't be huge, but it's there and just about anything can sound annoying if its pumped through a 4x12 stack.
Really, you need to check everything you own and stick terminating resistors on the front and output, even if the pedal normally works just fine on its own without one. The goal is to get TB and FET-switched pedals to "play nice" with each other.
Quote from: Mark Hammer on July 31, 2007, 09:15:08 AM
One of the somewhat counter-intuitive side-effects of the current true-bypass frenzy/cult/zeitgeist is that if you have a bunch of TB pedals in series and one of them somewhere has a "hanging cap", switching another pedal somewhere else can still produce a pop. Imagine we have 5 pedals in a row and pedal 1 has a hanging cap on its output. If all the otherpedals are off and I switch any single one of them on, there will be a brief instant where that cap is disconnected and then reconnected. Of course, since the pop is occurring when I'm switching one of the OTHER pedals, I assume that the problem is with them, when it it really isn't.
I might also point out that Boss pedals have a hanging cap on their input since they assume all switching will be done internal to the circuit, so the cap will never be left hanging or unconnected once you plug in. You get used to hearing a slight pop at that point, but you never hear a pop thereafter when you engage and bypass, so you figure everything is copasetic. But it isn't. The irony is that if you try and get Boss and homebrew TB pedals to play nice with each other, each time you engage or disengage the TB pedal just ahead of the Boss pedal (or even several ahead if you have, say, a couple of homebrew distortions followed by a Boss Chorus), that input cap is momentarily disconnected then reconnected. It's not a BIG cap (Usually .01uf, right?), so the pop shouldn't be huge, but it's there and just about anything can sound annoying if its pumped through a 4x12 stack.
Really, you need to check everything you own and stick terminating resistors on the front and output, even if the pedal normally works just fine on its own without one. The goal is to get TB and FET-switched pedals to "play nice" with each other.
actually....i don't even think its that the pedals aren't cooperating with each other nicely either. Every pedal i tried popped when it was just guitar to that one pedal to amp. Odd! I guess i'd rather address the TB pedals with LED's first cause....they annoy the shit out of me most. Pops so loud that it could actually interfere with the song. The BYOC board has a 4.4m (2x 2.2m resistors in series) pulldown resistor at the input. Not sure about the output.
after more testing, i've come to realize its like a microphonic pop. It could be that the TB pedals have a louder click when you hit the switch, so their pop is louder. I'm trying to find alternate cables to test if its a crap cable.
holy @&%^#%&^!!!!!
i get a noise.....if i flick my cable....wow....
Yeah, what do you think could cause this?
Some cables are in better shape than others. Beyond that, some plugs and jacks make better and more consistent contact with each other than some others do. Remember, it's all metal, and metal was rarely made to go boing. More often it bends and returns to shape more or less, but stays a little teeny tiny bit bent out of shape. The first phone jack on your pedal-board, and the plug going into it, as well as the guitar jack and plug, should be the best quality you can afford. The other plugs and cables on the board don't get moved around quite as much.
Man, its upsetting that i've tried several different variables, cables, battery vs. power supply, different pedals, i'll always get SOME noise. I guess its my DIY pedals that bother me the most cause i built them and i want them to be of the best quality.
So what are the ways to minimize LED pop on TB pedals? I've got the input grounding style wiring, Input Pulldown resistor....what else?
Well perhaps we might need to know exactly what your signal path is from guitar to amp. I certainly don't want to encourage "here's MY rig" bragging, but sometimes there are interactions between things that are inadvertently overlooked, so a bit more detail will help. If you can list the sequence of things your signal goes through and which are true-bypassed, that might help. For all we know, it could be your amp.
Just curious - you haven't done anything recently that might have offended a minor deity, have you?
:icon_biggrin:
Was you testing, guitar- one effect- prosonic?
Did you try another amp?
If you did and the pop went away
Did you change the tube that is connected to the input jack of the power amp?
Did you try a battery in the effects?
Quote from: Gus on July 31, 2007, 02:28:33 PM
Was you testing, guitar- one effect- prosonic?
Did you try another amp?
If you did and the pop went away
Did you change the tube that is connected to the input jack of the power amp?
Did you try a battery in the effects?
YouAre -
There are good clues here. Gus asked the big question before I could. Did you run all these tests with the same guitar? I suggest you repeat with a different one. Also, the battery test is another biggie.
I have a guitar lead that seems to have a couple of mV permanently hanging around on it. If I use that one, my pedals pop. Use the other one and they're golden.
There's a circuit snippet at AMZ here: http://www.muzique.com/lab/led.htm (http://www.muzique.com/lab/led.htm) that does a good job of limiting LED inrush current which can be a source of popping.
Aside from that, what Mark Hammer says above is sound (sorry - bad pun) advice.
Quote from: R O Tiree on August 01, 2007, 03:49:20 PM
Aside from that, what Mark Hammer says above is sound (sorry - bad pun) advice.
Could have been worse. You could have said I hit the nail on the head. Now THERE'S one I haven't heard over the last half century!! :icon_lol:
ok so i've been testing a bunch of different setups. The Most obnoxious pop is when i use the DIY overdrives with an LED. I'm going to try AMZ's led popping fix again and see if that does something. As far as the other buffered pedals, if i turn them on and off repeatedly, the click dies down.
So this brings me to another issue. True Bypass....i think i'd like to try something else! Does anyone have the layout/schematic for a simple buffered bypass using a non-latching switch? I'm sure one of jack orman's buffers can be retrofitted into a bypass. I ask if there's a non-latching switch because that mechanical CLICK seems to carry into the obnoxious pop. Anyone ever do that?
Some true bypass with LED designs say to use a bigger resistor with the LED to avoid popping sounds.
Quote from: grolschie on August 01, 2007, 05:08:16 PM
Some true bypass with LED designs say to use a bigger resistor with the LED to avoid popping sounds.
so there's a correlation between brightness of LED and popping?
It is curious that it still seems to happen no matter how you configure your setup. You say, even when reduced to a single pedal to amp, no matter which pedal it is, the popping still occurs. Have you tried setting up in another environment i.e another house/rehearsal room/garage whatever? Perhaps there is some other factor causing the effect.
I`ll risk incurring some scorn by mentioning the phrase "Dirty electricity". I don`t know enough about it but perhaps someone who is more knowledeable could say whether this might be an explanation.
Quoteso there's a correlation between brightness of LED and popping?
There is a correlation between LED *current* being switched and popping if you do your ground and power supply wiring incorrectly.
But let's get back to cases:
QuoteThere are good clues here. Gus asked the big question before I could. Did you run all these tests with the same guitar? I suggest you repeat with a different one. Also, the battery test is another biggie.
Have you tried eliminating
- the guitar?
- the cables?
- the amp?
- the tubes?
and so on instead of chasing LED current?
Quote from: R.G. on August 01, 2007, 11:16:03 PM
Quoteso there's a correlation between brightness of LED and popping?
There is a correlation between LED *current* being switched and popping if you do your ground and power supply wiring incorrectly.
But let's get back to cases:
QuoteThere are good clues here. Gus asked the big question before I could. Did you run all these tests with the same guitar? I suggest you repeat with a different one. Also, the battery test is another biggie.
Have you tried eliminating
- the guitar?
- the cables?
- the amp?
- the tubes?
and so on instead of chasing LED current?
i have been eliminating all day. Like i said, the buffered pedals lose their click once i just cycle the stomp enough. But the DIY true bypass pedals still pop pretty badly. so i'm trying feverishly to eliminate it.
Guitar, pops with both instruments
Cables, swapped them, still pops,
Amp, switched from tube to crate powerblock, still pops
I tried both styles of wiring that i mentioned before, WITHOUT the led, and i'm still getting a pop when the pedal is turned on, but NOT when bypassed. So i'm taking two 1m resistors, on the outboard sides of the input cap (.022 on the screamer) and output (10uf), as per the article of some kooky old effects weird guy. Here's the article http://geofex.com/Article_Folders/box_pop.htm
I'm seriously thinking about going buffer. Anyone know of any bypass buffers? I'm thinking of going the cornish way!
Go Millenium!
Won't pop then.
Have you tried using hi-brites run at a low current?
Just read the thread properly..
You must have DC sneaking in somewhere.
When you say even your 'buffered pedals' pop, do you mean commerical ones Boss etc?
Start with a known-to-be-good Amp/cable/guitar chain before anything else.
i tried going milenium, and i played around with putting 1M resistors on each lead of the input/output caps. I tried them in all different positions, and i still get a damn pop on my overdrive!
Can anyone tell me how to poke around to find the DC leak?
To see if you've got any DC leakage, poke around the pins of the stomp switch, if you've got DC on any of the pins apart from the one to the LED then you've either:-
got input or output caps that are too leaky
wired something up wrong so DC is getting where it shouldn't
got a dodgy switch
Do the measuring with just a lead plugged into the input jack to turn the pedal on (if you've wired it like that) and measure the voltage in both positions of the stomp and whilst switching it. If you don't get any DC where you shouldn't plug the pedal into your amp and do it again, if you get DC now it means it's your amp input that's got DC on it.
ok so i did some comparing!
i went out and bought a BBE screamer. Tried it out on my rig, and....pop! So then i tried out my pedal on an amp in a store, jcm800, and it popped at higher gain settings.
So i poked around in my pedal (returned the BBE by now), and just to make sure i'm doing this right, i clipped the black lead of the DMM to the ground lug of the power supply jack, and i poked around with the red. I'm using the regular bypass without LED, and no input grounding. The lug with the input and output of the circuit jumped up to 4mv then slowly died down to 0...odd?
Even more odd, The bypass on the switch (2 lugs jumpered together) went NUTS, jumping up to like 300-400mv. I don't get it.
Would putting big caps as "pulldown caps" help any?
An overdrive has a large gain. When you put a sudden change on its input, the change is amplified through it to a big pop on the output.
You found a 4mV change which died out. That means that a cap was charged to 4mv different from where it should be, and then charged up/down. Find out where the 4mV is coming from: leaky cap? flux/dust/dirt/corrosion on the board?/ incautiously placed pulldown resistor?
And no, "pulldown caps" won't help, they'll make it worse.
are there any buffers i could build that would pad down the input/output voltages?
cause I could simply tack those onto any other pedals that have a pop on them. I'd be giving up true bypass, but i don't mind.
also, where should the pulldown resistors be placed ideally?
OK, we're way out in left field here. Out in the weeds actually.
Can you list exactly the equipment that you're having problems with, from guitar through amp? All the parts, including cords and power supplies.
There are only a few possibilities. One is that you have a bad box in there putting out DC. Another is that you are one of those individuals that for better or worse is more sensitive to pops than the rest of us. There are others. The chances of you building yet another box to glom onto this chain of popping boxes that will fix it all is vanishingly small. Find the problem first, then discuss fixes.
So give us a list of what you have and I (and probably others as well) will try to lead you down the path to finding the problem.
First off, thanks to all of you who've been helping me out through this.
I would say i am pretty sensitive to the pops because i plan on selling a couple pedals. They're gonna be one off's to some people i know, but i try to keep high standards.
Here's the signal flow.
Gibson LP with Anderson HB's >> Cheap GC cables (or George L's) >> ts808 clone on BYOC board with 1meg pulldowns on input and output of circuit, powered by godlyke 9v power supply >> Another Cheap cable >> fender prosonic head into attenuator or crate powerblock or marshall jcm800 (in the store)
is there anyone to test if there's DC on my amp's input?
Quote from: YouAre on August 05, 2007, 03:35:58 AM
is there anyone to test if there's DC on my amp's input?
Yeah, with your DMM set to measure DC plug a guitar lead into the amp then clip the black lead of the DMM to the sleeve of the plug and clip the red lead to the tip. If you measure any DC then it's coming form the amp.
Quote from: slacker on August 05, 2007, 06:47:15 AM
Quote from: YouAre on August 05, 2007, 03:35:58 AM
is there anyone to test if there's DC on my amp's input?
Yeah, with your DMM set to measure DC plug a guitar lead into the amp then clip the black lead of the DMM to the sleeve of the plug and clip the red lead to the tip. If you measure any DC then it's coming form the amp.
when amp is on standby, there's -.495 mv. When its on, about +1.6mv
that contributes to the pop doesn't it....
bump