Taming Repeats on EQD Space Spiral

[Fatknuckle]

I have built this modulated delay, and the repeats/feedback feature is very picky.  It wants to give one repeat up to about halfway where it will give more repeats but runs into feedback oscillations very easily.  Is there a way to tame this, maybe add a tone control similar to the Deprofundus delay or something else? 

[jimilee]

Did you use a linear taper pot?


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[Aleph Null]

You could up the 1k resistor that connects to lug3 of the Repeats control. Higher values should make for less feedback. I'd probably try a 5k or 10k resistor in it's place.

[jimilee]

I am curious if you done the prerequisite troubleshooting steps. Triple check the layout against yours, check solder joints (those boys are tricky on Vero, and check component values and orientation.

[Aleph Null]

I am curious if you done the prerequisite troubleshooting steps. Triple check the layout against yours, check solder joints (those boys are tricky on Vero, and check component values and orientation.

Definitely do this before messing with resistor values!

[Fatknuckle]

Yes, been over the board in and out for a week.  Audio probe, lead dress, components, etc.  Posting for help is always a last resort before I give up and throw it in the gut bucket.  I did use a linear pot, and also experimented with adding a resistor.  After looking at some other repeats/feedback circuits on other delays, I opted to socket the cap on lugs 1 and 3 of the repeats pot, and changed it from 10n upwards sequentially ending on 100n.  Settled on 33n to taste.  It behaves much better now, and I feel much better about boxing it up.

Thanks!

[Fatknuckle]

It ended up being the PT2399, apparently knockoffs.  Found some reliable chips at Pedalparts, now this (and other projects) work much better.