Nerdseq Triggers to Doepfer A-142-2

[TonyBunn]

I checked the Doepfer manual, but it doesn’t say which levels are needed.
But usually for a gate/trigger input, even less voltage is needed to trigger/gate.

You can try just with a CV or Mod outout. Making it like slighly over 5 vplt and 0.

Thanks - tried the MOD output on Track 1. I increased the MOD value until I got a trigger on the attack phase of the VCA envelope. The trigger works correctly at value 333 - see photo below. The strange thing is on the scope the MOD output varies slightly around 2v and still triggers the VCA. Whereas the triggers which measure 3.46 to 3.54v are not triggering the VCA. So i'm baffled. Is there something subtly different about the trigger outputs? Current or impedance?. 



So in this set up the MODs trigger the VCA and the triggers of various durations do not. Same leads all with scope connected.

Thanks for your help with this. I could run using MOD instead of trigger, but I wanted to use the MOD out for modulation.

Cheers
Tony

Where do you get the in the trigger outs of 3.46 volt from? I see normal levels around 5 volt in your scope pictures.

Hi, sorry - I had switched to using the Doepfer voice A-111-6 to see if it would work or any difference. The A-111-6 behaves the same. But I just compared again. With the only the scope connected to the trig out the trig is just under 5v, 4.83v. When I connect the 142 VCA the trig drops to 4.67. When I connect the 111 (gate input) the trig drops to 3.46/3.54v. Sorry for the confusion. The MOD output with a lower voltage correctly triggers both modules. Seems like the gate input on both modules is slugging the trig, but not the MOD out.

[XORadmin]

Vmax is dropping to 3.46 Volt? That is very unusual. Are you sure you are not mixing Vrms by any chance in your readouts?

[TonyBunn]

Vmax is dropping to 3.46 Volt? That is very unusual. Are you sure you are not mixing Vrms by any chance in your readouts?

could be i'm not using the scope right - not an expert - will check

[TonyBunn]

Hi, yes definitely Vmax. 4.9v not connected 3.38 to 3.46v connected (on the A-111-6) and 4.67 to 4.75v (on the A-142-2). But the MOD out triggers both. MOD is 2.57v not connected and drops to 2.49v connected.

What do you think?

Sorry if this is taking too much of your time....

[TonyBunn]

Hi,

For info, to rule out any earthing or power problems, I moved the two Doepfer modules to power sockets adjacent to Nerdseq on the bus bar and disconnected all other modules. Still not getting a trigger of the attack phase on either module. 

Any further suggestions welcome - thanks for your support

Cheers
Tony

[XORadmin]

The voltage should stay around the 5 volt, also connected and might drop only slightly depending on the inputs of other modules, but a drop of 1 or more volt is definitely wrong.
But even 3,8 volt should trigger a well designed Gate input.

[TonyBunn]

The voltage should stay around the 5 volt, also connected and might drop only slightly depending on the inputs of other modules, but a drop of 1 or more volt is definitely wrong.
But even 3,8 volt should trigger a well designed Gate input.

Hi,

I just wanted to give you an update. I spoke with Doepfer to see if they had any ideas or in the input to the two modules could be adjusted. They couldn't help but thought it could be the rising edge or voltage level of the triggers. I suspect they need a very crisp and solid 5v trigger. 

As a possible solution, I purchased a Doepfer  A-183-4 module which  creates a selectable 5v or 12v trigger output (and seems to have a less finickity input) and happily, it has solved my problem. My NerdSEQ is now triggering my Doepfer models correctly via the A-183-4.

Thank you for your support. I think the NerdSEQ should trigger the Doepfer modules correctly without the additional module, and its a mystery to me what the root cause of the problem was, but in any case I'm happy its all now working, and I get some additional trigger mult capability with the new module.

Thanks again,
Tony

[XORadmin]

The raising edge of the trigger is perfect as it’s digital. That is for sure not the issue.

[Cedre]

But there is an issue somewhere. I have two doepfer A 140-2 with the same problem, I have to connect the retrig to the gate input to make them detect the trigger.

Maybe the issue is from these enveloppe, I don't know, but they work with other sequencer and midi to CV that I have.

[XORadmin]

I have Doepfer Envelopes here which works well.
Anyway, ordered a 140-2 just now to see what the problem is...