Moog Music Forum

hi moogerfooger users,

the noise output on my CP-251 puts out noise, but there is also a hum, I posted about this some months ago. Since then I had my unit sent back to the german distributor, where they changed the whole circuit board as I was told, and now the hum is almost unhearable, but still there. The hum is at about 50Hz, and the LFO rate has some effect on it - at 0.2 the hum is static, at 50 the hum´s volume fluctuates while the hum frequency stays the same.
Any CP-251 owners noticed that or can verify that for me?
Apparently it´s the LFO bleeding through to the noise, but is this normal, so to say the beauty of the analogue world?

The fact that it is 50Hz, the european wall voltage frequency, is highly suspect. If it is a constant 50Hz, its not the LFO bleeding through. The LFO may effect the hum, but it is not the cause.

You may be picking up the noise from your surroundings. Are you near any high voltage devices or do you live near some power lines?

Also, what sort of power supply are you using with the CP? The one supplied with the CP or one of those multiple pedal power supplies.

OysterRock wrote:The fact that it is 50Hz, the european wall voltage frequency, is highly suspect. If it is a constant 50Hz, its not the LFO bleeding through. The LFO may effect the hum, but it is not the cause.

You may be picking up the noise from your surroundings. Are you near any high voltage devices or do you live near some power lines?

Also, what sort of power supply are you using with the CP? The one supplied with the CP or one of those multple pedal power supplies.

Thanks for the reply. I use the supplied power supply only and have had the same result with the old circuit board wherever I tried (at home, rehearsal studio, various stages). Haven´t tried the cp with the new circuit board somwhere else, as I got back only yesterday.

I did have problems with electricity in my old appartment, I heard the washing machine in the speakers and such, but since I moved I don´t have this problems anymore.