Triggering a Roland Promars from a midi/cv converter

[J. Hahn]

Hi guys,

I'm having some trouble triggering the gate on my Roland Promars when I hook it up with my midi/cv converter - a Kenton Pro-2000.
I've set the Pro-2000 to output 15V on the gate - however I've measured the actual output to 13.67V, but according to a tech guy from Kenton, that should be plenty to trigger it. He suggested the gate input on the Promars could be defective or corroded. However, if I connect the gate output of the Promars (which outputs 14.2V) directly to the gate input, it triggers just fine. I suppose it would not be so, if the input was defective?

Have anyone here tried playing a Promars from an external cv/gate signal, and if so, can you tell me how much it takes to trigger the gate?

I should mention that the synth is otherwise in fully working order, and if I put it in "Hold" mode, I can change the pitch from the Pro-2000 cv output. Only the gate is giving me trouble.

Cheers
Jesper

[madtheory]

However, if I connect the gate output of the Promars (which outputs 14.2V) directly to the gate input, it triggers just fine. I suppose it would not be so, if the input was defective?

That proves nothing because the synth is still working from its internal trigger. Listen to the Kenton guy, clean the socket.

[Z]

I've triggered my ProMars from one of my TR-808's trigger outs and manually changing the notes, but that's all the interconnectivity I've done with mine.

My ProMars is on loan right now, so I cannot test it with any other gear at the moment.

[J. Hahn]

However, if I connect the gate output of the Promars (which outputs 14.2V) directly to the gate input, it triggers just fine. I suppose it would not be so, if the input was defective?

That proves nothing because the synth is still working from its internal trigger. Listen to the Kenton guy, clean the socket.

I did try and clean it. I've also opened up the synth and measured the signal on the inside of the gate input (where it's connected to wires). I can't find anything wrong with it. When you plug something into the gate input, the internal trigger from the keyboard is bypassed.

[madtheory]

Ah, cool. Looks like you need to check components further along the signal path.

[J. Hahn]

The problem turned out to be more simple and stupid than I could imagine.... from the factory, the cv/gate ins and outs had been switched.

[madtheory]

Great! An analogue synth running via MIDI is a thing of joy.

[adhmzaiusz]

The problem turned out to be more simple and stupid than I could imagine.... from the factory, the cv/gate ins and outs had been switched.

Resurrecting an old thread I know, but I just got a Promars... I couldn't get the gate in to work either. After some investigation of the schematic turns out the above wasn't completely correct. In the schematic the gate in and out jacks are normalized together via the gate in switch jack, the intention is the switch jack breaks the internal keytrig signal when an external input is used. If an external gate in is plugged into the output it will still work since the out jack isn't wired to be a switch. What the factory did wrong on mine (and possibly on others) was wire the gate in switch backwards. Basically the tip when broken went to the gate out circuit instead of the in circuit. Rewired it the other way around and now all working as it should. Maybe this will help anyone else in the future.

[madtheory]

Good of you to share that info on the web! Merry CHristmas.