Maxon CP9Pro+ distortion????

[the blast]

Help!!! My Maxon CP9Pro+ that I bought used here (LOOKS brand new) is distorting really badly. I have the Gain at zero basically, Threshold at -10 & Ratio at 3. When I first received it & plugged it in it made this distortion noise & I assumed it was the battery so I replaced it & it seemed to work fine. Now, a few months later, it's just full on fuzzy distortion. I'm now running it from a Voodoo Labs PP2+. It's been fine for about 15 rehearsals & then all of a sudden it just craps out. ANY ideas as to what this may be?

Best, -John

[nsh50a]

The only time mine has "fuzzed out" has been when the battery is going south. Have you tried taking it off of the voodoo labs and trying it with a fresh battery?

[Swift713]

Have you checked other possible sources of distortion? Cables, batteries in your bass, etc? The compressor could be amplifying something else.

[Blues Infidel]

Originally Posted by nsh50a

The only time mine has "fuzzed out" has been when the battery is going south. Have you tried taking it off of the voodoo labs and trying it with a fresh battery?

Mine also becomes noisy (and worse) when the battery gets soft, but is great with a good battery or running off a power supply. Agree with trying with a known good battery. Also want to make sure all the connections - battery/power supply and your signal - are all tight and clean.

[bongomania]

And we did just have a thread here recently where a person discovered that it was the battery in their active bass that needed replacing, and the compressor just amplified that distortion.

[the blast]

Only playing P Basses through it. New battery seems to fix it. Soooooooo bizarre that it's been fine for a few months & now it decides it doesn't like the PP2+. Maybe I need to combine the last 2 power outputs t give it more than enough juice??

[bongomania]

It could be that something has gone funky with either the DC jack on the pedal, or the charge pump circuit it uses. Do not feed it higher than 9V, they warn against that. On the one I had, the switch inside the DC jack failed, and I ended up just replacing that jack--it worked perfectly after that. Mine didn't distort, though, it just "worked" or "didn't".

[jscomposer]

You need to run it from one of the high current ("Line 6") 9V outputs on the Pedal Power 2+. They don't tell you this in the manual, but all their 9 series effects have what they call a "charge pump" which needs about 200mA on startup before settling on whatever current is cited in the specs.

I hope you haven't inadvertently damaged the thing!

And please, chuck the batteries. No sense in wasting money on batteries when you have a high quality power supply.

[the blast]

I actually have been. I did some research before I just went plugging things in. It's in the next to last (2nd from far right - 1st power output with sag control). Maybe I need to use one of the combining (Y cable) cables it came with????

[bongomania]

Again, do not send it higher voltage. The Y cable they included is for doubling voltage, not current. There is a special Y cable available for doubling current, but it is a special-order item.

[jscomposer]

Originally Posted by the blast

It's in the next to last (2nd from far right - 1st power output with sag control).

Scoot it one over to the left and you should be in business. Unless you've already damaged it by having it plugged into one of the sag outputs.

And like bongo said, do NOT use a y adapter to give it 18 volts. A single high current 9V output (either output 5 or 6) is what you want.

[the blast]

I'll move it one to the left as soon as I get home. I def wont try the Y cable as I don't know if it's for current or voltage anyway. I think if it were damaged the battery wouldn't work correct? With a new, strong battery it seems fine.

What's with this Charge Pump thing? I waaaay over research things before I buy them & never read anything about that. In fact today is the first I've heard of it.

Thanks for all the input guys,
-John

[bongomania]

It's a circuit that stores up charge and then releases it when it reaches a set voltage level. In this way it can take 9V in and put 18V (or some other voltage) out. It draws more current than a typical 9V pedal. It's used in a handful of pedals that operate better off higher voltage.

[the blast]

Well, seems fine now. Thanks guys.
-John

[the blast]

Well, not so fine now... It was fine at one rehearsal & just started doing its distortion thing again tonight. It's getting really annoying. This whole "charge pump" thing seems like it may not be the way to go. It seems as though it may be unreliable. I've been in contact with their customer service & I'll see what happens. I know I've recommended this pedal numerous times here but I may have to take it all back... We'll see.
-John

[bongomania]

Odds are greater that there is a bad solder joint or other intermittent connection inside, than that there is anything inherently wrong with the charge pump design.

[the blast]

You're probably right. I wish I had a tool to get inside of it. Unfortunately it's a star wrench of some sort that I don't have.

[the blast]

Sounds like they're going to give me a RMA number to send it in & have it looked at. I'll keep you all updated. Bongo, knowing that I really like the sound & functionality of this pedal, what others would you recommend? The Diamond, FEA or new Aguilar maybe? Talk soon guys, -John

[bongomania]

Each of those is a fine choice--it just depends on the specific qualities you're after. The Aguilar is "most similar" to the Maxon of those three.