Help! I can only hear noise from my first pedal

[Dante Stevano]

I've decided to build a very simple fuzz (electra distortion) guitar pedal for a school project.
I can only hear loud noise from the dirt channel, while when I switch my 3PDT the clean channel sounds fine. I can control the volume with my potentiometer just fine, but the noise is still so loud I can barely hear anything else.





This is how it sounds:
https://youtu.be/FW2E0sr4Oaw

I don't have access to any kind of kits in my country so I had to buy all of the components and figure it out myself. As this is my first shot at this, didn't quite go so well despite this being a very simple circuit. Should I give up and say this was a failed project?

[bluebunny]

Welcome to the forum.

Can you post the schematic you're working from please?  Also go check out the sticky "Debugging" thread at the top of this board.  Follow the instructions and report back here with your findings.

P.S. No, don't give up. 

[Dante Stevano]

Welcome to the forum.

Can you post the schematic you're working from please?  Also go check out the sticky "Debugging" thread at the top of this board.  Follow the instructions and report back here with your findings.

P.S. No, don't give up. 

Thanks!

Here are the schematics I'm using, I tested it in LiveSpice and it seems to work just fine.


This is how the breadboard should look like



I followed this diagram for offboard wiring since it was the easiest one I could find

https://tonefiend.com/diy/a-generic-stompbox-wiring-diagram/

The top left one is the one I followed for my 3PDT


I'll go and check off the debugging page,
Thanks again and I won't give up!!

[GibsonGM]

Welcome Dante!

I think you should have 2 jacks that are simply connected to input and output (and sleeve to ground) for testing.   Omit the switching, where the problem VERY often lies!  When the board is ready - after you have built the circuit on PBC - then you put together the switching, because you'll know the PCB is good and therefore the errors are in the switch and so on.

Are the diodes actually connected to the output cap?  It is very hard to tell with the box style capacitors.   

Look at where everything is connected again - is the 47k resistor actually going to the transistor's collector??  Is the 470k between collector and base, and the 680 to ground?

It is easier to supply power to the transistor directly from the 9V buss below the transistor, without 'wandering', so you can see this easily.  You may want to re-build the circuit, ensuring these things are correct...you'll become better at this as you build more things 

[antonis]

Hi & Welcome..

I think you've mixed R1 & R2 in your breadboard,,

[Dante Stevano]

Welcome Dante!

I think you should have 2 jacks that are simply connected to input and output (and sleeve to ground) for testing.   Omit the switching, where the problem VERY often lies!  When the board is ready - after you have built the circuit on PBC - then you put together the switching, because you'll know the PCB is good and therefore the errors are in the switch and so on.

Are the diodes actually connected to the output cap?  It is very hard to tell with the box style capacitors.   

Look at where everything is connected again - is the 47k resistor actually going to the transistor's collector??  Is the 470k between collector and base, and the 680 to ground?

It is easier to supply power to the transistor directly from the 9V buss below the transistor, without 'wandering', so you can see this easily.  You may want to re-build the circuit, ensuring these things are correct...you'll become better at this as you build more things 

Thanks for the advice!

I built the circuit again on a protoboard and this time it seems to work with just the two input/output jacks.
Although this distortion effect doesn't seem as loud as the digital simulations I tried, maybe I can turn it up with the potentiometer?

I think this is how it should work, do I go to soldering on the offboard wiring to the protoboard now?

[Dante Stevano]

Hi & Welcome..

I think you've mixed R1 & R2 in your breadboard,,

Oops... I forgot I drew that breadboard diagram wrong...
And yes the R1 & R2 should and have been switched around

Sorry I should've checked before posting lmao

[antonis]

Although this distortion effect doesn't seem as loud as the digital simulations I tried, maybe I can turn it up with the potentiometer?

With Volume pot up to max you'll get maximum loudness which is solely dependent on clipping diode pair forward voltage drop..
i.e. LEDs sound louder than Si diodes which sound louder than Ge diodes..

The higher the clipping threshold (louder) the "softer" the distortion so if you wish to maintain particular distortion with louder output you need some kind of "recovery" stage..
(a simple booster with A gain, where A = 4.5V / diode forward voltage drop..)

[Dante Stevano]

if you wish to maintain particular distortion with louder output you need some kind of "recovery" stage..
(a simple booster with A gain, where A = 4.5V / diode forward voltage drop..)

Sorry I'm not sure I follow...
Do I need to add another stage for more gain?

[Dante Stevano]

I built the circuit again on a protoboard and this time it seems to work with just the two input/output jacks.

I tried using my outboard wiring and switches with my protoboard, now the initial problem came back
I've already tried changing my output jacks before, and the bypass seems to work ok

Seems pretty far off but should I change my wires?

[Phend]

Read this article. It shows all needed to know about the Electra....Great article
(Start on Page 10 if you like)

https://roar-assets-auto.rbl.ms/documents/9052/Oct14_PGDistortion_BuildGuide_Final_R2.pdf

[duck_arse]

can you post a nice clear photo of your jacks that we might see how and where you are wiring them?

[antonis]

Do I need to add another stage for more gain?

Strictly speaking, yes..!! 

You need another stage for Volume..
That's output signal amplitude which, in particular circuit, can't be higher than clipping diode pair forward voltage drop..
(250-300mV for Ge, 300-400mV for Scottky, 600-700mV for Si and higher for LEDs..)   

[Phend]

Dante,
Hope you turn in a great report on making the Electra effect, lots of options to show, get an A+ with a killer effect.
Ph

[Dante Stevano]

can you post a nice clear photo of your jacks that we might see how and where you are wiring them?

I was following the diagram from my initial post since I wasn't able to follow some of the other diagrams I found

[Dante Stevano]

Strictly speaking, yes..!! 

You need another stage for Volume..
That's output signal amplitude which, in particular circuit, can't be higher than clipping diode pair forward voltage drop..
(250-300mV for Ge, 300-400mV for Scottky, 600-700mV for Si and higher for LEDs..)   

I was messing around with my circuit on a breadboard and found after replacing and switching around some resistors, the noise problem was completely gone!
At least from the board only using just the two audio jacks

I continued to mess around with all the other components to see what tones I can find and it ended up looking like this



I'm actually really liking this circuit, it has a sort of clear clean tone but also distorted if I hammer on the strings
So I might stick with this haha

Also the volume is now just as loud as my clean straight DI's volume, probably from the double(quadruple?) diodes

[Dante Stevano]

Dante,
Hope you turn in a great report on making the Electra effect, lots of options to show, get an A+ with a killer effect.
Ph

Thanks!
That means a lot and I also hope I get an A haha
I'll keep trying my best!!

[antonis]

I continued to mess around with all the other components to see what tones I can find and it ended up looking like this

1N4729A 3V6 Zener diode pair is useless without a selector switch..

Actually, Zener pair works as simple Si diode one ..
Only one Zener is needed for asymmetrical clipping..

[Dante Stevano]

Actually, Zener pair works as simple Si diode one ..
Only one Zener is needed for asymmetrical clipping..

Okayy, I'll just keep one in that case

[antonis]

Okayy, I'll just keep one in that case

So, you'll implement asymmetrical clipping (about 600mV for negative waveform and 3.6V for positive one) but only in case of selector switch..