Popping when I turn my Fuzzface "ON"

Started by chuckfalcon, January 07, 2016, 09:56:54 PM

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chuckfalcon

Hi everyone, I have been working on a pretty standard Univox Superfuzz circuit.  It works but there are a couple of issues.  It makes a "pop" sound ONLY when I turn on the fuzz.

Here are some things to note:

-I am using a 3PDT
-I'm not using an LED
-I put a 1M resistor from the input to ground
-I put a 1M resistor from the output to ground 
-I am not getting any DC reading from tip to ring on the input OR the output except for 0.001V (but that wouldn't really matter though, with a reading that small, right?)

I was getting a pop sound when I hit the bypass switch to turn the fuzz on AND off.  I looked at my wiring and my output cap's orientation was reversed.  So I swapped it.  No more popping when I hit the bypass switch to turn the effect off

Anyone know how to cure my popping when I turn ON my fuzz?

Also one other thing that I noticed.  When I power this circuit with a 1-spot and turn on the fuzz, I am hearing a high pitch humming sound.  When I power it with a 9V battery, it goes away.  What in the world could THAT be?

Any help?

peterg

Please post the schematic and layout you used.

chuckfalcon

#2
Okie doke.  Here is the layout:


Here's the schematic.  All I did was add the 1M's to the input and output:


chuckfalcon

One other thing that I noticed is that I can only hear the "pop" when the "gain/expander" and the "volume/balance" are turned up at least halfway.  What could this mean?

antonis

#4
You shouldn't use the 1M output resistor (it's purpose is covered by the 100k one..)

You should rename the -9V green trace on your layout as GND..  :icon_wink:

Maybe you have to try a 3PDT IN & OUT grounding wiring (despite of the bleed resistors)..


edit: I can't verify capacitors matching polarity on your layout..
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

antonis

 :icon_frown:
Quote from: chuckfalcon on January 07, 2016, 09:56:54 PM
I am not getting any DC reading from tip to ring on the input OR the output except for 0.001V (but that wouldn't really matter though, with a reading that small, right?)
If you multiply the 1mV on the Input with the overall circuit's gain, I'm not so sure if it remains small enough...
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

chuckfalcon

#6
Quote from: antonis on January 08, 2016, 07:24:26 AM
You shouldn't use the 1M output resistor (it's purpose is covered by the 100k one..)

You should rename the -9V green trace on your layout as GND..  :icon_wink:

Quote from: antonis on January 08, 2016, 07:24:26 AMMaybe you have to try a 3PDT IN & OUT grounding wiring (despite of the bleed resistors)..

Here is how I have the 3PDT wired.  I think that this grounds the input but not the output.  Could that maybe my problem?  Also, I am not using an LED and I don't have anything at all connected to the "LED LUG.




Quote from: antonis on January 08, 2016, 07:24:26 AM

edit: I can't verify capacitors matching polarity on your layout..

Whoops, sorry bout that.  I edited it and made them a little larger and not transparent.  I hope that helps.




Thanks for your help.  This thing is driving me crazy.