Rainbow Machine Clone Magic not working

Started by Dirtydrowningman, February 03, 2021, 01:20:44 PM

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Dirtydrowningman

Hey guys. I built up the rainbow machine clone from pedal PCB ( leprachaun) and everything works just fine except the regeneration. It doesn't work at all when engaged. Any tips or somthing I don't see. I had the fv1 pre soldered. Could it possibly be something wrong with that area. I am also using  cd4069ube instead of a cd4069ub?
Thanks







ElectricDruid

I found this:

https://www.pedalpcb.com/docs/Leprechaun.pdf

Unfortunately all it says is "schematic coming soon". So that's not much help.

If the Regen control is one of the the FV-1 Pots, you need to check that you're getting 0-3.3V from the pot's wiper when you turn the control, and that that voltage gets to the correct pin on the FV-1. If it's a hardware control...well, you'll have to trace it, since we've got no schematic. Sorry.

Dirtydrowningman

Thanks for the reply I will check when I get home.
A dude on pedal pcb actually gave me the schematic. It's not up on the site yet though.
https://forum.pedalpcb.com/attachments/pedalpcb-leprechaun-jpg.3801/

ElectricDruid


Dirtydrowningman

Sorry about that. I just uploaded it to imgur. According to the diagram the regen pot is not one of the fv1s. I was messing around with the audio probe last night. I did get a bit of a different sound when I poked around the regen stomp switch and can hear a little difference when turning the regen pot. The sound was a little different  compared to when probed on the output jack. But nothing crazy. It's not doing that crazy feedback sound its supposed to do.

Thanks.


amz-fx

Looking at your photo of the back of the assembled pedal...  the regen is turned on by the footswitch in the bottom right. If the right side of the switch is not working properly, you will never get any regeneration, so when on, the two poles on the right side should be connected together. Zero ohms.

Some of the pots on the schematic are not labeled the same as the final docs.

Regen= Magic
Dispersion= Tracking
Spectrum= Pitch
Color= Tone

This pedal only uses the internal FV-1 programs since pin 13 is grounded (and there is no serial memory chip).

regards, Jack

Dirtydrowningman

Thanks for the reply and info. I just tested the switch and got zero ohms so the switch seems healthy

ElectricDruid


antonis

"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..

amz-fx

Quote from: ElectricDruid on February 05, 2021, 03:59:24 PM
What connects M1 and M2 on the PCB?

The footswitch I mentioned.

Quote from: Dirtydrowningman on February 05, 2021, 12:40:44 PM
Thanks for the reply and info. I just tested the switch and got zero ohms so the switch seems healthy

The components to the right of the op amp in the bottom right corner of the pcb are related to the regen. I would replace the op amp and then check some solder joints in that area if the chip swap doesn't do it.

regards, Jack

ElectricDruid

Quote from: amz-fx on February 05, 2021, 05:04:15 PM
Quote from: ElectricDruid on February 05, 2021, 03:59:24 PM
What connects M1 and M2 on the PCB?

The footswitch I mentioned.

Ah, ok. Thanks Jack.

Quote
The components to the right of the op amp in the bottom right corner of the pcb are related to the regen. I would replace the op amp and then check some solder joints in that area if the chip swap doesn't do it.

+1 agree. There are a lot of parts in this area that could conceivably prevent the regen from working. Bad joint on one of those 1u caps, short across a resistor or diode, etc etc. Lots of possibilities. Check that part over carefully.

Dirtydrowningman

Antonis, jack, druid thanks so much for the replies here. They mean a lot. I will inspect that area later on today and switch out that Tl072