Hello diyaudio !
I'm trying to repair a french analog multi-effect unit
The unit is a Europa DP400C.
It's a great piece of equipement... but i cannot find any schematics
Main PT was blown, replaced it with a spare 12VAC PT. Now it lights on.
But some function don't work (delay time is always at maximum i guess, chorus has no effect unless i wiggle the speed knob)
I'm a guitar tube tech ; don't now much about thoose complicated board...
Maybe someone has some time to help me ?
I have a good DMM, a scope, a function generator...
The no-working pots are mechanicaly ok.
potentiometer order :
1st picture
compressor : sustain / level
overdrive : distorsion
2nd picture :
overdrive : distorsion / level
chorus : speed / depth
delay : time / feedback / level
high def pictures :
IMG-20200413-153350 — ImgBB
IMG-20200413-153357 — ImgBB
I'm trying to repair a french analog multi-effect unit
The unit is a Europa DP400C.
It's a great piece of equipement... but i cannot find any schematics
Main PT was blown, replaced it with a spare 12VAC PT. Now it lights on.
But some function don't work (delay time is always at maximum i guess, chorus has no effect unless i wiggle the speed knob)
I'm a guitar tube tech ; don't now much about thoose complicated board...
Maybe someone has some time to help me ?
I have a good DMM, a scope, a function generator...
The no-working pots are mechanicaly ok.
potentiometer order :
1st picture
compressor : sustain / level
overdrive : distorsion
2nd picture :
overdrive : distorsion / level
chorus : speed / depth
delay : time / feedback / level
high def pictures :
IMG-20200413-153350 — ImgBB
IMG-20200413-153357 — ImgBB
Last edited:
Transformers usually blow for a reason. Those 19 ancient historic electrolytic caps look like a good reason. have you checked the power supply voltages?
You have one 22 pin IC that might be a microprocessor. I don't see the accompaning PROM or ROM for the program, but that is because I can't read the IC names. PROMS & ROMS sometimes forget, which is irretrievable unfortunately. But dodgy power supplies, that is something every old piece of history has pretty likely. Electrolytic caps, the time fuses engineers build in to make sure you buy a new appliance at the right time. I wouldn't jump in replacing them until you measure the PS voltages as outside the tolerance of the IC's installed. Have industry numbers on them it appears, you can look up the datasheets to see what the voltages should be. datasheetcatalog.com for pdf's. Don't look up letter prefixes and suffixs, mostly those are manufacturer code or package code. Letters in the middle of the numbers matter.
Note voltage regulators & zener diodes are high failure parts too. Also pots, especially the wipers lose contact.
You have one 22 pin IC that might be a microprocessor. I don't see the accompaning PROM or ROM for the program, but that is because I can't read the IC names. PROMS & ROMS sometimes forget, which is irretrievable unfortunately. But dodgy power supplies, that is something every old piece of history has pretty likely. Electrolytic caps, the time fuses engineers build in to make sure you buy a new appliance at the right time. I wouldn't jump in replacing them until you measure the PS voltages as outside the tolerance of the IC's installed. Have industry numbers on them it appears, you can look up the datasheets to see what the voltages should be. datasheetcatalog.com for pdf's. Don't look up letter prefixes and suffixs, mostly those are manufacturer code or package code. Letters in the middle of the numbers matter.
Note voltage regulators & zener diodes are high failure parts too. Also pots, especially the wipers lose contact.
Last edited: