I picked up a MXR Carbon Copy about a week ago. Took forever for me to find a delay I liked, but this finally became available at the local guitar store. So I gave it a test drive and pretty much instantly fell in love with it. It was exactly what I was lookign for.

I've been playing with it pretty heavily over the past few days to get a feel for it and just to see(hear) what it's capable of. I tried all of the example settings that are provided and all were excellent. Then I began dialing in some custom settings and it all sounded great. BUT (you knew it was coming), yesterday plugged in and powered on and I got a horrible, deafening screeching coming from my amp. And it was the delay that was causing it. I had achieved this same screeching previously by really messing with dials, cranking all of em up to max and then dropping the delay time down to 0. But other than "forcing" it to happen by screwing with the dials, it had never happened before.

I'm running everything through a Mesa Boogie Roadster 212 Combo with active EMGs on the Guitar and the Carbon Copy in the effects loop. No dials on the amp or guitar had been touched from when the delay work fine previously. The only "change" was that I left the Carbon Copy plugged in for a day and the battery died so I found a 9V adapter to power it instead. Now, whenever I bring the Regen dial past 10-12 o'clock (depending on where the Mix dial is at) I get that horrible screeching. Also, no matter what the other dials are at, when I zero out the Delay time (or close to it) I also get the screeching.

I know that it's not just bad choice of settings on the delay that are doing it since I had previously tried the example "Slap" setting without issue, but now everytime I dial that in it screeches like a banshee. The delay still sounds great if I keep the Regen and Mix below 12 o'clock and the Delay above 7:00. But I shouldn't be limited to just that range!

Now, I have a Decimator G-String in the mail as we speak, but I'm not even sure if it would help. That's beside the point anyway since I didn't actually NEED a noise surpressor for this delay pedal to work "properly" in teh first palce. So, any thoughts? Is there something obvious (or nto so obvious) that could be causing this that I just can't pinpoint? Or has the damn pedal already crapped out on me?

P.S. Sorry for essay.
Yeah, I dunno. I'm pretty sure it's setup properly. Pretty straghtforward I think. I got it running through the effects loop by itself. Only pedal I have hooked up currently. Like I said, it worked perfectly fine before. Don't really know how you could set it up wrong...

Another note: The screeching doesn't just occur on the high gain channels. It's just as bad on the clean channels as well. Also, turning modulation on and off doesn't make a difference either.

EDIT: Since you mentioned "wrong power lead" it got me thinking. I'm gonna pick up another 9V battery on my way home from work today and test it out to see if maybe it is actually the adapter that's causing the problems.
Last edited by Erkekjetter at Oct 10, 2008,
Well, I tested it out and it turns out the screeching is actually a result of switching from the battery to the power supply. But it's not actually a problem with the power supply. It's a problem with the pedal.

I tested the battery I thought had died and it actually apparently has full juice. So I popped it back into the Carbon Copy and turned it on. I had no problem with screeching, but I did notice that the delay effect was much more subdued. Almost as if the battery wasn't providing the full amount of power (the battery is quite old and possibly "expired"). I actually tried a brand new battery as well, but it actually behaved just like the power supply. The delay screeched like crazy.

So essentially, an old (but fully charged) battery caused no screeching, but had significantly lower level of effect. A power supply or brand new battery provides a full strength effect, but causes tons of screeching.

Can anyone else who has a Carbon Copy confirm that this just the nature of the pedal itself? Like I said, I can't even use some of the recommended sample settings they provide without it howling. Is it simply just behaving asintended? Can you just not turn the Regen past 11:00 and/or drop the Delay time to nearly nothing? And if so, would a noise supressor help the problem? Or is my brand new pedal just completely effed?
Last edited by Erkekjetter at Oct 11, 2008,
I had that same problem with with my single recto. I couldn't run the carbon copy through the Fx loop without it making a weird thumping noise even on the lowest settings. I even took back a nova delay because I thought is was the pedal but it turns out that there is something about the fx loops on the recto that cause this. I just moved my delay to the front of the amp and i have to live with it.

ps. I have a clip of what the CC sounds like in front of the amp with distortion on my profile its called test.
Last edited by Muramasa at Oct 11, 2008,
Thanks for the info Muramasa. It's good to know that at least it's not my pedal. Even worse, it's the amp... That sucks. :p

I listened to your Test and the Carbon Copy still sounds excellent in front of the amp so it's not a bad alternative by any stretch. Thanks for the suggestion. I'm still gonna wait for my Decimator to arrive and see if that helps at all, but if not I'll just bypass the effects loop in this case. Kinda sucks though, if I bring the Carbon Copy to the front of the amp then I'll have nothing running in my effects loop, which pretty much means I got the Decimator G-String for nothing. Had I known earlier I could've saved myself $100 and just got the regular Decimator instead.

Oh well, no regrets.
I just don't like the effect loop on the recto, I think the problem is that it doesn't allow 100% mix through the loop instead its like 90%. Let me know how that Decimator works i'm really interested if that works or not. I'm just really pissed that i got rid of an awesome Nova Delay because I thought it was the pedal and not the effect loop. But I love the sound of an analog delay and I could not justify getting the Nova again when the CC has such a great sound. Well have fun with and don't forget to mess around with the internal trim pot inside the CC, it lets you adjust the depth of the chorus.

By the way NICE AMP. I'm glad i could help out another Mesa owner.