Vintage Synth Repair

"freeloverdk" <michael@...> wrote:

<< Here I am again. As I said on previous posts, I just bought this Arp 
Odyssey Whiteface. It 

has a CV/GATE build in as well, but I cannot get it to work. I have the 
Roland MPU-101 

interface (that I already use for my SH-101 - which is working like a charm). 
 >>

Unfortunately, your Odyssey wants to see a gate that's bigger than 5 volts.  
Your MPU-101 puts out a 5 volt gate signal.  The ARP needs at least about 10 
volts to trigger its envelopes.  You may have to build a little level-shifting 
circuit to make it work.  It can be done with two transistors and a few 
resistors.