Problem with MXR Carbon Copy mini

smigeon

I have MXR Carbon Copy mini on my board. At rehearsal this afternoon, it became faulty: on every repeat it made an audible ticking noise, or (if turned up more) a loud banging noise. It's powered by a Cioks PSU on an isolated line, so it shouldn’t be a power problem (I hope!).

A quick google doesn’t reveal other cases of this happing out there in the world. But I was wondering if anyone here had experienced this, or knew what might be the cause and a possible fix? It’s only a few months old...

Rusty-Strings

I recently had a similar problem on my newly acquired carbon copy mini. Mine is on an isolated supply and the ticking noise was present unless bypassed. I was planning on raising the issue with Andertons the next day but when I switched it back on the noise has gone and hasn't reoccured.

smigeon

Thanks. I’ll try mine again with a different power supply - although it’s been fine with the Cioks for months. I got mine from Thomann and apparently they’ll “repair” it under the 3 year guarantee scheme that they run. And they provide a pre-paid label to return it with. Sounds like a good scheme on the face of it - as long it works out in practice. Hope yours stays fixed!

Petepassion

I bought a new one through Reverb from Coda music with the same problem about six months ago, must be a common fault.

Rusty-Strings

The noise has returned! Sometimes its there on power up, sometimes it starts after the pedal has been on for some hours. Its a motorboat noise which is affected by the rotating the delay knob.

Moe_Zambeek

Have you added any new pedals? I had a Germanium range master style pedal
that was silent but induced noise on other pedals down chain, initially thought it was a trem making a ticking but after experimenting it turned out that the trem was silent if the Ge was off board.

smigeon

I tried my faulty one in isolation and it was still faulty (motorboating). 

stonevibe

I’ve heard of this issue a few times with these. So could well be a common issue. 

Rusty-Strings

The Carbon Copy is being used on its own, powered from a Voodoo Labs Pedal Power 2+ and a plugin battery. The noise is sometimes there on power up, or if not, starts after the unit has been left on (2 - 3 hours yesterday). Power cycling doesn't clear it unless it's unpowered for some hours.

Habanero

This might sound like a daft question, but do you have a powerline ethernet connection? I do, and a couple of pedals I have pick up an odd ticking and crackling unless it's turned off. It took me about a year to find the cause.

smigeon

Habanero said:

This might sound like a daft question, but do you have a powerline ethernet connection? I do, and a couple of pedals I have pick up an odd ticking and crackling unless it's turned off. It took me about a year to find the cause.

Not in my case. Also, the ticking/motorboating is synched with the delay setting on the pedal. It surely seems unlikely that interference from an external ethernet signal would cause that.

Rusty-Strings

I don't have powerline ethernet either.

Habanero

Oh well, never mind then

Rusty-Strings

It's being picked up and going back to Andertons today!

smigeon

Mine’s on its way back to Thomann - for “repair” rather than return, as I’ve had it too long (while it was working) to just send back. Will be interesting see how “repair” works out!

Rusty-Strings

Yes, mine is going back for "repair" too!

Danny1969

I suspect these pedals have a fault that's causing a reverse bias of an electrolytic capacitor .... generally when this happens the cap will heal it's self to a point if left to drain down and then biased the right way. But a recurring fault of this kind will kill the cap or leave it with such a high ESR it won't be able to do the job it's there for anyway. 

I see these kind of faults all the time on laptop motherboards. Modern SMD caps aren't exactly robust. 

Nerine

Sounds to me like the clock isn’t being filtered out of the signal path correctly.