Trouble with Profex II

[Harold Power]

I have a profexII connected to a Peavey DPC 750 and two BW 15's. The profex has the Fox mods.This unit has always been very noise free. Lately it has become extremely and unbearably noisy in most all presets.
AS soon as I change from one preset to an other the noise starts immediately.
Any help would be greatly appreciated. Thanks in advance. H. P.

[Brad Issendorf]

Hi Harold. I have a Profex II that I bought new and have used continuously since like the early 90s. My first suggestion to you is to check to see if the power supply for the Profex is somehow too near an audio cable or connection to the DPC unit. Guitar cables and patch cables can often be affected the fields that the transformers or "wallwarts" create. If that isn't it, try rotating the output knob of the Profex back and forth a few times. Years ago I had mine sent to Ken Fox for the upgrades and he called and told me that the pot in the output was dirty, but that if you rotated them back and forth that they would "self clean" themselves and get rid of the noise too. Just my thoughts, hope it helps in some way.

[Harold Power]

Thank you Brad for your reply . I have tried all your suggestions, still no change. When unplugging the power source from the profexII and then plugging back in again the noise stops for a few seconds then immediately starts again.The wallwart is not near the unit,that was moved years ago to reduce a previous hum.Many thanks Brad for your reply. H. P.

[Jack Stoner]

What kind of "noise" do you have? Is it like a low frequency AC power hum or static or high frequency (white) noise?

"Reseat" the cables between the Profex II and the Power Amp (Unplug then plug back in - on both ends).

[Harold Power]

Jack, the noise is a loud high frequency white noise. Reseating cables makes no difference.Disconnecting the power plug from the Profex then repluging stops the noise until I play the guitar or change the Profex to another preset, then the noise starts again.
The volume pots in the DPC 750 are also scratchy,could this be the problem? Also the Profex outputs are left & right, the inputs on the DPC are A&B, which is the correct way to connect the cables?
Jack,thank you, your help with my problem is really appreciated. H. P.

[Jack Stoner]

I would suspect an op-amp chip as "first thought". Been a long time since I've been inside a Profex II so I don't know if there is more than one of the same chip. If there is, swap the chips and see if the symptoms change.

If you have a Cache card with your user programs on it (so you can reload), do a factory reset and see if that helps. Seems to fix many problems.

[Mike Brown]

Try reinitializing the unit by unplugging the power adaptor, then pressing and holding down the PLAY and GLOBAL buttons simultaneously, then plugging the Profex II power supply into the wall socket. Release the two buttons and your Profex II will be reset, but you will have to reload your preset using a RAM cartridge. Hope that this helps.

[Harold Power]

Thank you to Jack Stoner and Mike Brown,for your help in solving the problem with the ProfexII. Also thanks to the Forum for making available such willing and sharing people. H. P.

[Jack Stoner]

Glad to help. Another Nova Scotian, Bob Lawrence, helped me fix my MatchBro.

[Paddy Long]

when you did the chip ugrade did you also remove the battery and put in the batteryless chip ?? a leaking battery would cause a fair bit of damage if left to it's own devices ????

[Harold Power]

Hello Paddy;

The Profex has the Fox batteryless mod.
Reinitializing to factory settings cured the problem. Thanks, H. P.