I am working on an ADA flanger, I believe it is a reissue from the 90's. I have read many helpful posts on this forum and I hope you all can help me solve this puzzling pedal.
It came to me not working, only passing clean signal. I inspected all the caps, chips, pots switches etc... and found no clear faults, so after some reading I decided to replace the cheap and readily available i.cs. And wham, she came to life and I was happy.
What a radical pedal! Then, after about two months it failed again. Would work intermittently, suspected capacitor failure. Replaced all electrolytic caps, and Q1. No dice. I could driver her into self oscillation with the trim pots, but only seemed to be producing half the sweep. kinda sounds like a bubble pooping then whooooooossssssshhhhhhhhhh blip....then silence. And that time could be effected with the speed control, but only in self oscillation. Input signal could be traced through to the input of the mn3010 ic but the output was a mess. So I bit the bullet and ordered an mn3010 and waited a month and a half for the slow boat from china. Annnnnnnnd, no difference. So sad.
So now, I have reviewed as much info as possible, obtained schematics and checked voltages and replaced a ton of parts. Ive scoped and probed and still cant nail it down. My main suspect is something with the power supply to mn3010. I see the DC voltage on the output pins vary with the self oscillated output, between 7 and 14 volts. A post on here said their output pins sat at about 7.5 volts. Honestly I am no wizard with the bbd. And the op amp in IC4 seems to be slamming on the rails at the same tempo. The traces on the board are all gnarled and look like old tin foil bubbled up, but continuity testing shows they're ugly but functioning.
IF any of ya have any help for this stumped chump I would be so appreciative. I'm about ready to breadboard the circuit one part at a time cause I cant keep chasing gremlins in this old machine. Thank you.
