Mxr carbon Copy

[brujo]

Hi there, a friend brought to me a carbon Copy that does not respond very much to potentiometer, their are rated b100k, I cleaned them and now It Is a little bit better, but far along from where It should be. I measured resistance of pots and never go over 50k. Any suggestions? Anything else that i can check on pcb? Thank you a cheera to you all

[r080]

It looks like you posted this under Digital & DSP. You might want to ask the mods to move to a different section.

Is this the old Carbon Copy with the power cable, or the new one? If the new one, have you been able to find a schematic?

Can you explain a little more what the pots are not doing?

[brujo]

Sorry for the wrong section...how can I reach a mod?
Is One of the new One, mostly surface mounted components and no I was not able getting a schematic.
Basically the pots are doing nothing, in fact with all pots at maximum I get Just a Little bit of delay. Aldo there are a lot of trimmer but i really don't what voltages should I set.
I opened and cleaned One of the pots and seems ti be good.
Any help would be really appreciated
Cheers

[vigilante397]

While we're waiting for a mod to get it moved (Carbon Copy is an analog delay, not digital/dsp), have any of the internal trimpots been adjusted? Playing with bias in an analog delay will produce anything from distorted signal and lessened control response to no signal at all. That's always the place I would start in an analog delay.

[brujo]

I really agree with you about the biasing, but I am really going blind here

[percyhornickel]

A few months ago I wrote to MXR about a problem with a friend´s carbon copy. It was a version 1 which is knowed beause many  came out with a design problem. The unit was very old and after we send the pedal they send back a brand new one Version 2 to replace the other.

We are in Venezuela so they were so kind and explained to us we would have to pay the shipping from here (we sent the pedal with anothr friend)  and they could cover the shipping back once the they fix the unit.

You could try to write or call them up first before an invasive fix.

My advice...

Saludos

[soggybag]

I have a carbon copy, it's the dark green sparkle in the 1590B sized enclosure. The Repeats knob does do much. Nothing really until over 80%.