CP-251 S/H problem

peterkeys88 · Post by **peterkeys88** » Fri Jul 24, 2009 1:52 am

HI folks, just got a used Cp-251, with the white rings. Ive been fiddling with it today and it seems the plain S/H out1 doesnt go as wide as the on on my Voyager, or the CP-251 s/h used in the moog demo with brian kenew, even when hooked up simply. Has anyone else had problems with the S/H?

ebo · Post by **ebo** » Thu Oct 29, 2009 11:25 am

Hi! I have the same problem with my CP251 and the S&H outs.I try the setting in the manual ENV- MF 101to S&H trigger in.I sended the CP251 back to moog germany .It came back. but the was the same problem I think the voltage from S&H out is to low.EBo

Voyager.Taurus2.Prodigy.Crumar Spirit.2x MF101.MF102.2xMF103.2xMF 105
MF105B.MF107.CP251.VX351.MP201

Portamental · Post by **Portamental** » Thu Oct 29, 2009 4:01 pm

Yes, the max output of the S&H is +/- 2 volts peak to peak, while a regular CV is typically -5 to 5. (I have not checked the Voyager specs on that yet). It's not without hope, especially if you take a peek into the Voyager forum from time to time.

Amos · Post by **Amos** » Thu Oct 29, 2009 4:52 pm

a simple trick to get more voltage out of any CV signal, using the CP-251 (the CV does not need to originate in the CP-251; this works with any CV):

connect the CV to the input of the 4-way Mult. Take two outputs of the mult and connect to two inputs of the 4-channel CV mixer. Now turn up the mixer knobs; at maximum you should have double your original voltage range at the CV mixer output.

Cheers,

Amos

GregAE · Post by **GregAE** » Fri Oct 30, 2009 7:28 am

Amos is correct about the 'voltage doubler' trick using the CP-251. But you can get away with just using inputs 3 & 4 on the Mixer, like so:

Simple and effective - and works for any control voltage!

- Greg

ebo · Post by **ebo** » Fri Oct 30, 2009 7:37 pm

Good morning!I tested the voltage doubler,now I can hear a little bit.It was better when I took the noise from the MP201.because the voltage of the CP251 noise was also very low.but I miss the deep.Is it possible to change the S&H voltage inside the CP251?(Change a resistor)The unit is running with 9V.What happend with 12V?Ebo