Beginner breadboarded fuzz issue

Started by Locrian99, June 19, 2022, 12:56:05 PM

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Locrian99

Well I had some issues with pedal cramming all 4 pots etc into the enclosure was fine until I tried to put the back on (also I bought the 1590b enclosures not realizing the 125b was just a little larger)   Decided to redo my pot wiring and man did I screw up, was trying to hurry while the wife had the kids at her sisters lol.   Apparently I managed to somehow ground everything in my screw up.   Both input and output tips on the jacks I can put my black lead to, place read lead on + and I get 9 volts.  Every pin on the 3pdt too.   So I looked at everything I've got a couple pot leads I've noticed are wrong which I'll fix.  My big screw up is I added the "smooth" pot to the input, 1 would go to the 3pdt and 2 would go to the board input lug 3 does nothing worked great.   Well I got myself confused and put heatshrink over lug 1 and ran lug 3 to the 3pdt.   And that was the long winded way to my question.   I haven't decided if it's worth redoing that part if it's just going to cause the taper to be backwards, which I think is all it would do.   Is that the case or would that cause other issues.   Thanks guys, and next order 125b and enclosed jacks for sure!

duck_arse

You hold the small basket while I strain the gnat.

Locrian99

Argh well all the pots are wired back correctly.  No audio from the audio probe at input jack and the tip still appears to be grounding out to me.   Along with everything else on the 3pdt.   I am correct in that I should get 0 volts with the black lead on the tip of the jack and red lead at 9V+ right?

duck_arse

at the in and the out jack tips, you should always read 0V DC, or only a bit of a millivolt.

You hold the small basket while I strain the gnat.

Locrian99

K.   Am I correct that since the black probe is on the on the input tip and red to +9v (in this case I'm reading at my dc jack or the boards +9 that it's is grounded?

antonis

By placing BLACK probe on to power jack GND (0V) and RED probe ANYWHERE outside PCB, you should read 0VDC..
(provided In & Out DC blocking caps, of course..) :icon_wink:

"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..

duck_arse

I'm not sure what it is you are trying to measure at the tip_in and +9V. generally speaking, in the pedal universe, we reference to ground [that is, put the black probe to ground (whether positive ground or negative ground)], and then poke at the DC parts of the circuit with the red probe [which will result in minus voltage readings w/ positive ground, and which will indicate correct method].

the sleeve of the jacks is always ground. the tips of the jacks are always considered AUDIO parts of the circuit, not DC parts of the circuit.
You hold the small basket while I strain the gnat.

Locrian99

Thank you guys, I'm a bit confused on what was happening there.   I didn't change any wiring and for some reason I was getting what appeared to me to be voltage at the tip of the input jack my reason for measuring this was I was getting jo audio signal there with the audio probe.   I found a book im reading through a chapter on this portion to understand it better.   As I was getting confused as to what was happening and apparently my issue was either unheard of or I wasn't searching correctly for it. 

Locrian99

Antonious I understand there are different ways to wire the 3pdt.   I was using this one: http://1.bp.blogspot.com/-k5Sh68yVU18/TzGRFKbiALI/AAAAAAAAAlk/CbfaaduUjYQ/s320/%21Offboard+wiring.png

You mentioned the dc filter cap is that is basically just preventing any voltage from finding its way back to switch?   

This circuit is getting frustrating, it was working fine until I tried the screw the back on the enclosure.   I had to force it a little.   Spent more time on it last night, was getting no guitar signal, there was a fair amount or "noise" and turning the fuzz and tone pots seemed to affect it.   Checked voltages first and was reading just over 1 volt at the q2 collector, also noticed a couple questionable solder joints so I fixed those and replaced the q2 collector resistor with another 5.6k.   Thought it was weird that I was getting such low voltage now as I had it at 4.69-4.7 before so I check the resistor ohm reading after it was off the board and I got 5.57k which seems about right 1% tolerance plus whatever I'm getting from my probes and alligator clips.  I Had the voltage back to 4.7, had kind of a muffled sound, that sounded fairly clean though.   But for sure a lot of noise in front of it if that makes sense.  In my twisting and turning of the circuit I broke one of the solid core wires to to the tone pot, I replaced it with stranded and got out the audio probe.    Followed the signal it sounded good from the input clean tone.   Jumped over and checked at the q2 collector/base emitter all have sound all sound clean.   Etc etc audio everywhere but it's clean.   I hook the output of the board up again to try it out, and I've got a nice clean tone without all the noise.   But I was making a fuzz!   I check the voltages again just because we'll it seems like the thing to do.   Q2 collector is now reading 8.8, but it was just 4.7 and I've done nothing to anything near there on the board.   I check other spots in the board everywhere I'm getting 8.8.   Where the 33k comes off the 9v check the other side I'm getting 8.8.   Here's the vero layout I used.  https://2.bp.blogspot.com/-nPaHDtR-WzI/U0lTqr3hJjI/AAAAAAAAGsI/W3wd1dkZ9CY/s1600/NPN+Fuzz+Face+with+BMP+Tone+Stack+2.png

Oh the volume knob works, the tone knob works but the change doesn't seem as drastic but that might just be in my head.   Fuzz doesn't really do anything that I can hear.  I don't understand what could be causing those voltage swings, and I'm feeling somewhat confident that is why I'm not getting any fuzz.   Prior to putting the board together I checked for continuity with the multimeter to make sure my cuts were good.   And I've examined the strip side pretty well to make sure there are no solder bridges between the strips.  I didn't see any couple places I run and exacto knife through a few times just to make sure.   

antonis

#49
To be honest, I'd try a brand new build.. :icon_wink:
(after all, it's just a 12 X 9 stripboard..)'

edit: Just a moment..
Do all the above happen with curcuit still on breadboard..?
"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..

Locrian99

It's on strip board.   I was leaning towards making a new I was just hoping I'd have that a-ha moment Looking at it as to what was causing the problem.   Just seems so weird that it's doing what it's doing.   Thank you again for the suggestions.   I was debating even posting what I had going on, I was pretty determined to figure it out last night.  I just didn't get it how the voltage would change like that.   

 

antonis

 :icon_smile: :icon_smile: :icon_smile:

Twisting and turning doesn't help a ciruit's health, does it..?? :icon_wink:

Topped(8.8V) or bottomed(1V) Q2 Collector calls either for cut-off (perhaps due to "open" Emitter) or saturated (perhaps due to "shorted" Emitter) working region..

Could you plz take some measurements on Q1 Base & Collector..??
(the later should be identical to Q2 Base voltage..)
"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..

Locrian99

I swear this thing is changing voltage every time I check it which leads me to believe I have some cold solder joints etc that are intermittently connecting.   When it is reading the 4.7, q1 collector and q2 base are off by .2 volts.    It's time for me to just start another piece of perf board and give this a fresh start.   I've soldered, removed solder, etc etc on here too many times in a few spots I feel like anyways.   

duck_arse

as antonis always sez, don't make duck ask for photos. why no photos of your stripboard build yet?

also, to save me another posting - did you test your soldered build before you put it in the enclosure? have you tried dissassembling it from the enclosure and testing it on the bench?
You hold the small basket while I strain the gnat.

Locrian99

I guess I could've posted pictures of the strip board.   It worked outside the enclosure.   Worked everything wired up in the enclosure.   Then I tried to screw the back of the enclosure on and kind of make it fit.   It no longer worked.   Then I rewired my pots as things were tight and looked like thag could be an issue.   Then I had weird (to me at least voltage at the input tip and no sound in bypass.   So I took it out and have been testing it outside again.   Which is where I was able to get the just clean tone passing through.   I keep getting different voltage readings at different points constantly.   So I think I'll just as Antonious suggested start over on a new piece of strip board before that though I'm making up an actual test box rather than just some jacks and power ran to a terminal strip sitting on my bench.    Hopefully I'll get that done start fresh wire inside of the enclosure cleaner and be much more careful about forcing this time and have learned a couple lessons from this one. 

antonis

Quote from: Locrian99 on July 02, 2022, 01:11:43 PM
It worked outside the enclosure.   Worked everything wired up in the enclosure.   Then I tried to screw the back of the enclosure on and kind of make it fit.   It no longer worked.

Those enclosures which ought to be hermetically closed have caused countless issues.. :icon_wink:
(honestly, no irony at all..)
"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..

Locrian99

Yea I should've just stopped and strategized the wiring better.   I think that will be a focus on attempt #2.  And using stranded wire at least for the pots. 

Locrian99

Here is the stripboard in case you guys spot something obvious before I start my 2nd attempt.   




bluebunny

Quote from: Locrian99 on July 02, 2022, 07:42:29 PM
Here is the stripboard in case you guys spot something obvious before I start my 2nd attempt.   


If your stripboard was this tarnished before you started soldering, then you likely have some dodgy joints.  The copper needs to be shiny pink before you start.  Try not to touch it with your fingers once it's cleaned.
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GibsonGM

I like to clean them with #0000 steel wool prior to soldering. If you want to go an extra step, after that wipe the copper w/acetone to remove any 'process oils' and any that may be in the wool.
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