Aion Quadratron (Lovetone Doppelganger)

[aion]

I didn't have any of these issues in my prototype either which used 2k pots, but I'm going to change the docs so 2k is no longer the default and only mentioned as a possible mod with caveats since it's happened more than once. I would put a 2k or 2k2 resistor across the lugs of the span pots (can solder from the top of the PCB without disassembling) to drop the value back down to the stock 1k. You could try increasing the parallel resistors to 3k9 or 4k7 to get a little more range without getting into lockup territory.

[benny_profane]

I measured the resistance of the B2K pots. They're within spec (about 2050 ohms each). I compared LEDs from different orders. The batch containing the LEDs I used for the build measured a little low (Fv ~1.8V). These were from an older order. The more recent order was a bit higher and in line with published specs. Do you think that that could cause an issue? I don't have a problem replacing the LEDs if that could fix the issue.

I'll put together a video soon and start a new thread.

[aion]

It's worth a try. The LEDs seem the most likely culprit. The LFO has a fixed range of modulation (no biasing) and is attempting to modulate the LED brightness within a given range, impacted by the Span pot. If the LEDs are more efficient or sensitive then it seems they'd be more likely to stay on at a certain point when the fixed-range LFO expects that they'd still be modulating.

[danfrank]

Hi Aion!
What's the latest on the Roland Jet Phaser PCB???
Woo hoo!

[aion]

Hi Aion!
What's the latest on the Roland Jet Phaser PCB???
Woo hoo!

Ran into a PCB layout issue and so it got bumped to the bottom of the stack for awhile.

[benny_profane]

New thread started in general questions:

https://www.madbeanpedals.com/forum/index.php?topic=32974.0