Volume drop and weeping sound from Punk Repeater

Started by ghiekorg, November 24, 2020, 10:23:04 AM

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ghiekorg

HI guys :)
Here is the layout: https://effectslayouts.blogspot.com/2014/11/dirty-punk-repeater-delay.html
Schematic SHOULD be this one, i haven't found a better one:


It works, the repetitions are kinda clean but i have 2 problems:
1- a really big volume drop when engaged. I used everything as layered out, i just changed the Q2 (BC459b) for a 2N5089 and i used 2 resistors (1M+330k) instead of the 250k i didn't have.
2- a sweeping sound when rotating the time knob: https://www.youtube.com/watch?v=UI5qxT5BFUo&ab_channel=ghiekorg (volume up :) )

Can you help me fix this?
Thank you

11-90-an

My guess would be a flipped transistor

Weep sound is normal...  :icon_mrgreen:

If that doesn't work then pictures plez... :icon_mrgreen:
flip flop flip flop flip

ghiekorg

Quote
My guess would be a flipped transistor
Nope :D

QuoteWeep sound is normal...  :icon_mrgreen:
So much? 0.0 i mean, there is a constant whistle

QuoteIf that doesn't work then pictures plez... :icon_mrgreen:
of the board? i would have to disassemble the pedal as i kept the wires super short  (i can take pics of the solder side though)

I was thinking maybe there was wrong (or something to be add) in the schematic (like something to push the volume up, addind a vol pot and some filtering session to filter the whistle) :/

antonis

#3
Shouldn't an electro cap (10-47μF) be connected between pin 2 (Analog reference voltage - Vcc/2) and GND (Analog - pin3)..??

"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..

11-90-an

#4
QuoteNope :D

Just to get it straight, the perf layout showed the wrong orientation of the BC549. It is actually the correct pinout for a 2N5089 though... :icon_rolleyes:

QuoteSo much? 0.0 i mean, there is a constant whistle

Oops... didn't really hear it too well... :icon_redface:
Here's how the pedal should sound like... https://www.youtube.com/watch?v=a-aDx46PMaU (skip to 4:08)

Quoteof the board? i would have to disassemble the pedal as i kept the wires super short  (i can take pics of the solder side though)
yea the board... but I think other forumites could come up with a solution without looking at component side pictures so maybe solder side will do for now... :icon_mrgreen:
flip flop flip flop flip

Rob Strand

QuoteShouldn't an electro cap (10-47μF) be connected between pin 2 (Analog reference voltage - Vcc/2) and GND (Analog - pin3)..??
No cap across the 5V rails isn't good either.
Send:     . .- .-. - .... / - --- / --. --- .-. -
According to the water analogy of electricity, transistor leakage is caused by holes.

anotherjim

The sweep whine would be expected with that design. It does almost nothing to prevent it. This might be deliberate, but I don't know why you'd want it to do that. Maybe I'm just not punk enough!
If you have a 9v battery snap to 2.1mm DC adapter, try powering it with a battery that way and see what happens to the noise.