help on a wampler analog echo+

[ξεναγος νεκροπολης]

hi there guys.
i redrew the schematic for the "madbean leviathan" using kicad, and put the "dirtbaby" modulation part in it.

i want to make a pcb board that has it both onboard. i love how leviathan sounds, and i really believe this is one of the best pt delays out there.

now...i've already made a pcb of it with my cnc machine, but it doesn't work. i'm pretty sure everything is connected as they sould. i took my time on this. step by step. tested everything. but now i'm back to the starting point.
i get some very distorted slapback style repeats but only when delay pot is full ccw. by the time i will turn it cw just a little bit, it goes straight to crazy oscillation. i've audio probed the board, and distortion kicks in at the 1uf after tl072 pin 1.

can somebody take a look at the schem and say if there is something wrong with it?? i basically copied and pasted the whole schem of the leviathan, and the mod part of dirtbaby..(i know about those two 120k resistors that should be 100k on the schem. the board has the right values)



http://www.madbeanpedals.com/EP/schematics/Leviathan.gif

http://www.madbeanpedals.com/projects/Dirtbaby/Dirtbaby.pdf


thanks in any advice.
i'm about to make a vero layout out of this schem, cause it's easierfor debugging. i'll post it here too.

[Ciaran Haslett]

The schematic is missing a 120K in the LFO but other than that it looks fine.  Maybe post some hi res pics of your board?  Can't be much more help than that I'm afraid

[ξεναγος νεκροπολης]

yeap...i noticed that after i exported the pdf...copy paste mistake.....i feel like i'll never learn how to properly use cad programs!!!

anyway..

i got it shorted! it was a bad regulator. it was giving something like 7V and that's why it was kinda working.did that ever happented to any of you???
nothing burned out though.it works like a charm!

i've build a second vero with the dirtbaby mod-part-daughterboard too.it also works perfect...
now i have a leviathan in a 1590b, and two other boards with modulation...
the pcb sounds much cleaner than the vero i think..i'll check it again when everything gets boxed.

so the schem is double verified(plus the 120k in the lfo as Ciaran  spotted.
i'll draw a single vero in the next days

sooo happy!!!
chears
Savvas

[traktop]

ξεναγος νεκροπολης wrote

i'll draw a single vero in the next days