DIY deluxe memory man with V3205 chips

[marconoschese]

Hello everybody

I'm Marco from Belgium. This is my first post on this forum but I've been following and reading for some time now. I started making effects about 2 months ago. But before that I've built some tube amps and fixed a couple fenders and peavey's.

Well I'm building a DMM now with coolaudio V3205 chips.

I'll explain what mods I have done to adapt this circuit to these low voltage chips.

U10 - 79L15 .. ouput -15V goes to al opamps except U2 , V3205's and CD4047

The CD4047 and the two V3205's are fed with -5V out of a 79L05. Now I have swapped pins 1 and 5 for polarity (negative supply) and connected the pulldown resistors to the 79L05 completing the polarity switch. So voltages for these two chips should be ok.

The CD4047 runs off -5V too which if you look at the datasheet is a normal operating condition.

When I send a signal in it arrives perfectly at pin 7 of the first V3205. I've tried every position of the bias adjust pot but no signal is coming from pins 3&4 which are the outputs. ( i have a scope)

All the files can be found here : http://www.scribd.com/doc/17686325/Analog-Delay-Layout

What seems to be the problem here?? I have tried to solve this one but for now unsuccessfull.


Thanks in advance. ^^


(on a south american forum i've found a topic with a working version with this pcb, so it's verfied. But that's with mn3005)