#1
I need some help, I am sure its nothing major but I am electronics challenged somewhat..I have an ashdown chorus plus pedal there is a knob that lets you dial in from chorus to flange, at about 3/4 the way to flange and on to full flange there is a high pitched squeal that will react to the speed and other adjustments,,when the dial is all on chorus there is no noise and chorus works great any ideas or educated guesses at what I should look at, I can solder and change out parts but dont understand the therory behind electronics components so i need help from a tech type user
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#2
I'm not familiar with chorus or flange pedals, but squealing in audio circuits has mostly happened to me as a result of grounding issues. I'm sure there are other possible causes, but this might be as simple as opening up the pedal to look at the circuitry and noticing a wire that seems to have come loose or broke in some way. If the problem wire isn't obvious to you though, you're going to need to wait for someone who's familiar with the circuits and how this could be put together for more troubleshooting.

If your pedal is entirely on a circuit board then it could be hard to notice grounding problems, but if it isn't I'd start by seeing if you can see any broken wire that would be coming from the potentiometers or "dials". After that I'd see if you can identify one that looks like it's going to the case of the pedal.

I apologize in advance if this doesn't end up being a grounding problem.

For others that may reply with more knowledge: Could a filtering cap be shot?
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#3
thank you for your input I will do as you say...wish me luck
This is my guitar
There are many like it but this one is mine
My guitar is my best friend it is my life
I must master it as I master my life
My guitar without me is useless
Without my guitar I am useless
#4
mabe this pic will help someone I can send hi res if someone needs a closer look
Attachments:
ug1.jpg
This is my guitar
There are many like it but this one is mine
My guitar is my best friend it is my life
I must master it as I master my life
My guitar without me is useless
Without my guitar I am useless
#5
Ok the squeal in the Ashdown chorus plus when on flange all the way is fixed by removing the cap in C41 on the PCB and either replacing R42 with a 3Kohm resistor or putting a 8.2K ohm resistor in parallel with the existing resistor..this way sounds best but either way works...now my pedal works great ... I paid 20 bux for a 100$ pedal that was broke easy fix..i love it
Attachments:
ug3.jpg
This is my guitar
There are many like it but this one is mine
My guitar is my best friend it is my life
I must master it as I master my life
My guitar without me is useless
Without my guitar I am useless
#6
Quote by camara53
Ok the squeal in the Ashdown chorus plus when on flange all the way is fixed by removing the cap in C41 on the PCB and either replacing R42 with a 3Kohm resistor or putting a 8.2K ohm resistor in parallel with the existing resistor..this way sounds best but either way works...now my pedal works great ... I paid 20 bux for a 100$ pedal that was broke easy fix..i love it


You are correct. The squealing is caused by an oscillation loop that has spun out of control.