noise, noise and still noise

[pipporan]

i've build something like 15 diy pedals until now, most of them are clones, some others are diy projects (not mines, i just copy them )
the effects are very very nice (4 distorsions, 1 noise gate, 1 fuzz, 2 octave down, 2 octave up, 1 phaser, 2 overdrives, 1 tremolo, 1 vibrato, 2 boosts etc etc), but ALL of them have a lot of noise
i think the noise is divided in 3 cathegories:
1)"pop" or "clack" sound when 3pdt is pushed. i tried everything i could to eliminate this loud sound: eliminate led, add a circuit to the led (http://www.muzique.com/lab/led.htm), change 2 variety of 3pdt stomp switches and a plastic kind of 2pdt, i tried to ground all the effect, i tried to wire the 3pdt in some different ways (grounding PCB input when effect is bypassed, for example), but NOTHING worked at all. so i'm still asking: WHY? why is doing this? do i have to surrender to the fact the 3pdt switches do this noise, if you dont buy an expensive one?
2)electrical noise: with this i mean a kind of noise that is not "modulated" from volumes or guitar or the quantity of audio signal. It just stays there. Is it a normal consequence of the fact that i'm using plastic boxes? i tried to put a supply filter on the power, and on the input signal (like this: http://www.muzique.com/lab/hum.htm), i also tried once to "cover" the whole plastic box with aluminum sheet, but any of these things worked, neither a little
3)signal noise: the kind of noise that "interacts" with the audio signal, Of course, on distorsion type effects, there is much much more. what can i do to lower it? shielded cables? group wires together? keep different kind of signal (power supply, input, output, gain pots etc etc) away from each other?
i lost lots of hours triyng to fix these 3 issues, but until now, i solved nothing. any suggestion will be very very much appreciated!!!!

[blackieNYC]

Be careful resoldering the stomps over and over. They can melt and fail. Let's hold off on the plastic boxes for a moment.
1- when the signal gets past the switch to the circuit input, the first thing it should see is a 1 meg (or more) resistor. Standard stuff. Are you talking about an electrical click coming from the speaker? I'm assuming you are.  Some circuits' stomps are switching AC-only audio signals (if a leaky electrolytic is on the input or output that can pop. Try film caps only-1uf), but there are a few that are switching some DC, which can give you a pop.  "Tails" switches on a delay. The millennium bypass should not. The LED circuit - good try.  I believe the better switches are for longevity and not poppiness. Answer:sounds like youve got it right. I don't know.
2- indicates the noise is in the output stage. But again, I don't know
3- indicates noise is in, or before a gain stage. Shielding does help a little.
Plastic boxes - try aluminum foil on ALL of them, not just one!  Most need a metal chassis for shielding. It sounds like everything up to there is right, and that There is a very big There. If the foil works, you can get adhesive backed foil tape (copper even).
You might want to transplant a couple into a metal box. With a grounded 1/4" jack.

Are some of these kits? Or pcbs?  With either of those mistakes are less likely - at least one other person has looked it over besides you. And they're usually very reliable.  I would not expect lots of noise on all of them. Very very few.
Is it possible (your post requires me to ask a stupid question), that your expectations are too high?  Boss pedals have no mechanical click nor electrical click when working right. I'm not saying DIY pedals do, I'm just wondering how you set the bar for "too noisy".  Know what I mean?

[EBK]

Plastic boxes?  While they are not causing your noise, they are preventing you from eliminating it, so your noise is a consequence of using them.

Some light reading: http://www.geofex.com/article_folders/plasticbox.htm

[GibsonGM]

Minimally, you must shield the interior of a plastic (or other non-conductive) box.  To not do so is to invite noise and other interesting sounds in.

I have found that no high gain pedal that I build can be 'click or pop free'.  I don't "play" too many of these, tho, luckily - they are on at the beginning of a tune, and usually stay on, or can be turned off in the tune and are covered by other sounds.   To me, it's just a consequence of mechanical switching (outside of the normal problems like DC level shifts, which we build in protection for). 

On your 3)...yeah, there are things.  Keep in/out away from each other...wires cross at 90 degrees.....shielded wire (on input mainly), route wires in a 'smart way' to not bring high level signal wires near inputs that are low or they may couple....good ground plan (star grounding).    Is your hiss really THAT bad??

[pipporan]

well, first of all, thanx for help!!!

answering in order: about the "pop" when switching, several of the effects i built have the pulldown resistor on input or both in e out, and the "pop" is present even on the pedals i bought by kit, that are assured (by the guy that sold them to me and he has my complete trust) to be good switch, and the pop shouldnt be there!!!! surely it's definitely not a problem of some caps or some electrolytic cap, 'cos EVERY stomp i build does this awful, terrible, loud "pop"

blackie, you suggest that problem number 2 could be something on the output stage...i dont know, but i can say that i think it's some interference from outside (the only effect that i put in a alluminum box have a lot less of this noise): the noise is really "background" (even if it's loud enough to be bothered by), and it doesnt vary with gain, or volumes

dont worry about the "stupid question", i would ask the same question replying to my post : but i can assure you that it's not a problem of "too high expectations": the pop is loud as much as the effect volume, the background interference noise is tolerable, but it's very present anyway (i mean, could be not a big issue in a dist effect, but in a tremolo is quite bothering), and the signal noise (that appears in "messy" and loud effects only) is sometimes litterally louder that the effect itself!!! i dont care about having perfect and totally silent effetcs, but i spent LOTS of time and LOTS of money in buying, thinking, soldering, boxing etc all this stuff that is a bit frustrating to have a result under decency

i asked to the guy that sell the kits i bought (big muff, proco rat and noise gate similar to MXR), and he says that all these sympthoms are not normal at all, he said to try to use batteries instead of adaptors and listen to the difference... for him, part of the problem could be some continuos tensions from the circuit before or after the effect, so he asked me to measure it (at pcb IN and OUT)

in next days i will take a pedal, remove it, and cover the inside with aluminum foil, and see what happens...
then, i'll put a ferrite bead taked from an old adaptor on the supply power...in next pedals that i'll box, i'll do a smarter use of wiring, crossing them and coupling them with a logic
and, if i still want to put money on this, i'll but aluminum boxes

Be careful resoldering the stomps over and over. They can melt and fail

i dont...i dont desolder stuff unless im forced to or im sure that i'll do an improvement...to make experiments, i use circuit not boxed yet, i wire with "flying" switches, and i use led or supply filter just with terminal strips 

[pipporan]

mmm if i try aluminum foil: it must be on the inside...or on the outside???

[EBK]

mmm if i try aluminum foil: it must be on the inside...or on the outside???

Doesn't matter.  Inside would look better.
Just don't put it on your head....  https://www.theatlantic.com/health/archive/2012/09/tin-foil-hats-actually-make-it-easier-for-the-government-to-track-your-thoughts/262998/ 

[thermionix]

Just don't put it on your head....  https://www.theatlantic.com/health/archive/2012/09/tin-foil-hats-actually-make-it-easier-for-the-government-to-track-your-thoughts/262998/ 

If you want to be sure...



(Yes, of course it's Florida.)

[rankot]

1)"pop" or "clack" sound when 3pdt is pushed. i tried everything i could to eliminate this loud sound: eliminate led, add a circuit to the led (http://www.muzique.com/lab/led.htm), change 2 variety of 3pdt stomp switches and a plastic kind of 2pdt, i tried to ground all the effect, i tried to wire the 3pdt in some different ways (grounding PCB input when effect is bypassed, for example), but NOTHING worked at all. so i'm still asking: WHY? why is doing this? do i have to surrender to the fact the 3pdt switches do this noise, if you dont buy an expensive one?

From my, not so big, experience, this is sometimes unpredictable, but could also be connected to mechanical problems of the switch itself. So, try to put plastic washer that comes with a switch under the enclosure, or above it, or even try without the washer. This could eliminate the pop entirely.

[ElectricDruid]

If *all* your pedals are very noisy, I'd look carefully at what you're feeding it. Perhaps your guitar isn't grounded properly. Maybe the connection to the jack in the guitar is giving up, or a wire's fallen off a pot internally or something. I've heard quite a few very hummy guitars over the years. Also your cables. You need a decent shielded cables between the guitar and the pedals, and between the various pedals. Broken connections in the cables can introduce a lot of hum and noise, and reduce signal so you finish up boosting gain and hearing more hiss. Finally, the power supply. If you're powering all these pedals off a supply that's noisy, you're feeding noise into your signal via the supply rails. So there's plenty of possibilities for noise to get into the pedals that are nothing to do with the pedals!/b]. That might explain why you haven't found anything wrong with the circuits.

HTH,
Tom

[stallik]

When investigating switch popping, connect one pedal at a time. It's very possible that a 'fault' on one pedal only shows up when you switch another. I think it's called pedal ventriloquism and it can be a pain to find out which one is the culprit.
I have a Morley wah which does this but have never been able to fix the root cause.

[pipporan]

update: some new "experiments" tried
first of all, my stupidity always surprises me: issue number 2 (electrical interferences not variable with volumes or gain) is for 90% an issue of the amplifer i'm using these days...i can say this for sure because the background noise is very similar with the effect plugged or unplgged:-)
ok, sorry for having you bothered with this
but the other two problems remain the same
for the switch, i just tried to remove the plastic washer (and then the metal ones, and then both together) from the 3pdt; and i discovered that the "pop" changes in pitch and a bit in volume if you remove some washers, or you tight the bolt more or less...but, apart from this discovery, the "pop" remain loud and clear as much as the effect itself!!

When investigating switch popping, connect one pedal at a time.

i always do so...just the pedal i'm experiment with and nothing else...at this point, i would think that it's a mechanical problems of the switches, but AT LEAST the effects that i bought on kit shouldnt be affected by the "pop" problem...the guy that sold me these kit assured me about this, and i completely believe him...

about noise in general, i discovered that shouldn't be a problem of supply: i switched power between 9v battery and an adaptor (to be able to hear the immediate difference), and there is no difference AT ALL...the noise doesnt change at all ebtween battery and adaptor, so it should be a matter of that

doing these experiements i found 2 new things:
1)measuring voltages on input and output (putting black connector of multimeter on ground and red on input and output signal) from the board it gaves -0.17 volts, on both input and output when effect is engaged, and just from input when effect is not engaged...i tried this with 3 different effects (one from kit), and with both batteries and adaptor: always the same -0.17v...and i realized that it comes from the amplifier: when i disconnect jack (from effect to amplifier) from amplifier this tension magically disappear...so, this thing keeps on leading me on the fact that this amplifier (an old little marschall valvestate 10) has a big part in this noise issues

2)when i was experiements with vibrato (magnavibe, builted with the great help of the people of this forum ), i saw that
if with a hand i was touching the + side ad the supply jack while this was bringing power to effect, and with the other hand i was approaching the board, i could hear another interference coming: nearer my hand to the board, louder the backgroung noise; and it was modulated by the effect: i could clearly hear the variety of "depth" and "speed" in the interference turning the depth and speed pots!
is this normal? with the box open and having my conducting hand near the solders, is it normal to do this kind of interference?

for third issue, the "audio-noise", i've found nothing new...
anyway, next step will be to take my great valve amp and see (hear) what happens with that one...and cover with aluminum an effect...i'll keed you updated...thanx for now, guys!

[deadastronaut]

are you going into built in dirt on your amp?..

or clean, and adding your own dirt?


my marshall valvestate 275 onboard dirt is great, but noisey /hissy as hell...and pretty much unusable loud

so i use the clean channel and add my own dirt...nice and quiet. no hiss..

this doesn't address your pop issue...but hey one stage at a time.

[pipporan]

no no...i use this amp at home only!
for serous use, i have a tube amp that's great!
for playing at home, i use this, and when i try my diy pedals, i always do it with clean amp, but i never realized how dirtyand messy it were!!!
even if, this discovery doesnt coverall the issue: the pop of course, but even a lot of other noise...
for examplke, a few minutes ago, i discovered that (with the magnavibe): the pedal standing on the floor do an addictional interference noise compared to the pedal kept a 30 degrees from the floor!
i dont understand this thing, but the difference in noise is something like 25% less, just tilting the pedal from the floor!!!
every day there're some mysteries more 

[J0K3RX]

Try an audio probe and see if you can pin point where in the circuit the noise increases. Sounds like a grounding problem, may even be causing the switch pop..

[pipporan]

Try an audio probe and see if you can pin point where in the circuit the noise increases. Sounds like a grounding problem, may even be causing the switch pop..

wow i really didnt think of it!
i'll try it too!

[pipporan]

ok guys...i say in advance: sorry for the time i made you lose
most of the problems were about amplifier: today i tried some pedals with the other (the good one) amplifier, and 2/3 of background noise of the popping soung went away...
there are still some noises and interferences, but i guess they are in normal range of a DIY pedal made by an ignorant about electronics...
sorry...if you ever come to florence (italy) i will offer you a coffee

[rankot]

ok guys...i say in advance: sorry for the time i made you lose
most of the problems were about amplifier: today i tried some pedals with the other (the good one) amplifier, and 2/3 of background noise of the popping soung went away...
there are still some noises and interferences, but i guess they are in normal range of a DIY pedal made by an ignorant about electronics...
sorry...if you ever come to florence (italy) i will offer you a coffee

I don't drink coffee, but tea would be nice

[Rixen]

I investigated switch pop and click experimentally, and found the switch itself is piezo-electric. Just hitting the switch body with a screwdriver can generate electrical noise.

scope pictures, this is a passive circuit; 1M resistor with scope probe and switch contact across it. Nothing left floating:

[pipporan]

i let here a possible explaination, given to me by the guy who sell the diy kits, so other people who experiment lots of background noises can start from here, before losing hours going crazy
if there is some tension on PCB input and output (in my case, it was -0.17v), it could be the capacitor on the bypass of the preamplifier, that begins to be ruined, and instead of blocking tension, let it pass through the circuit.
Or it could be a little DC tension, that overlaps to a low frequency AC tension, that goes all over the circuit.
The tension on PCB IN and OUT must be always 0, 'cos otherwise when you push the switch, the potential difference (between the two parts of the circuit that are connected by the switch) makes the DC tension turns in a signal that arrives to the exit; and so the "pop" noise is made!!!!

recapitulating it: if you find some tension on PCB input or output, try another amp/cables at first: the noise could be not pedal's fault!

hope this will be helpfull to someone

1M resistor with scope probe and switch contact across it.

with 1M res did the pop drastically diminuish?

I don't drink coffee, but tea would be nice
me neither, and i like tea too...i'm strange italian, from this perspective