Delay-Verb (Zero Point Micro featuring two Cave Dwellers)

[seedlings]

Hi all, first post.  This site is a fantastic resource.

I've been playing with PT2399 circuits for a few months now in search of a customizable reverb circuit for my pedal board. I had circuits breadboarded with two or three PT2399 chips in various configurations and feedback arrangements, until the circuit sounded nice. Unfortunately, my attempts at a layout were not pretty. Combine that with intermittent success at etching, and I decided to buy three madbean PCBs, which would cover the basics of the circuit on my breadboard, though not exactly.

The Madbean Zero Point Micro is a standard PT2399 delay with modulation. The Madbean Cave Dweller is a stripped down delay (with a slightly confusing two-pot feedback arrangement).

My pedal is the stock Zero Point Micro circuit with two series Cave Dwellers in the feedback loop. So the ZPM's delayed signal goes through both CD circuits before it's fed back. There are several capacitor and resistor changes, but, if you built them stock it would still work fine.  The signal leaves the ZPM board where lug 3 of the feedback pot would be connected.  That signal goes into one Cave Dweller, who's output goes to the second Cave Dweller, and then on to the feedback pot lug 3.

Something happened with windows media maker and the volume level of the mic'd amp signal is too quiet. Oh, well...

CHAD

[jimilee]

Hey!!! Welcome to the forum, what a great build. Gutshot?

[spaceboss]

Nice to see such a creative use of the Cave Dwellers. Really interesting and cool project.

[seedlings]

This is the guts before the boards were folded over to solder ins, outs and ground to the footswitch.  It's neither sexy nor noisy.  Without the ability to manage sexy guts, I settle for functionality 




CHAD

[lincolnic]

This is a fantastic first post. What a great project you've made!

here are several capacitor and resistor changes, but, if you built them stock it would still work fine.

So what changes did you make, and what effect do they have? What would the difference be if you'd built them stock?

[Stomptown]

Dang! Looks and sounds great! Welcome to the forum. Looking forward to seeing more!

[seedlings]

This is a fantastic first post. What a great project you've made!

here are several capacitor and resistor changes, but, if you built them stock it would still work fine.

So what changes did you make, and what effect do they have? What would the difference be if you'd built them stock?

Stock would be have brighter repeats.

For both cave dwellers, I changed
R1 to 15k, (reduce noise)
R2 to 20k, (reduce noise)
C2 to 10n, (compensate for lower R2)
C3 to 10n, (wanted darker repeats)
the dwell pot is a fixed 27k resistor between 2 and 3,
R8 is 4k7

In the ZPM,
C19 is 3u3 (only taunt cap I had that would fit the little space)
R18 is 100k
R19 is 100k
C13 is 10n (I didn't have any 15n)
RT is 1M pot
MOD is 1M pot

CHAD

[televisiondown]

This is really clever! It's great how you can still hear the characteristics of the cave dweller with such a clean delay. Awesome! You should put this in the monthly build contest (if you haven't already)

[Jean-Rock]

Hmm !! Very inspiring build, congrats mate !!