[sdiy] Substitute for IMF-3958 ARP 4015 S/H SubModule

[James Dunn]

> So, pretty much everything works as a direct replacement PIN to PIN as 
> you mentioned below except :
>
>> 2) Connect R391 (47k) of S/H clock input to pin 12 of Yves Usson's S/H.
>
> this is not working since Yves S/H module I believe expects as Square 
> Wave signal (then it works) and the ARP is generating that weird 
> trigger signal nobody can use but ARP. I even have tried the other way 
> around triggering my Modular DIY synth's S/H (same module) from the 
> ARP it won't budge.Is there a little circuitry that I could put in 
> front of Yves circuitry to accept the ARP trigger signal .Or maybe 
> remove some parts . Because the other way around I would have to tap 
> into R288,R386 to get the clean Square to work.
>
>
>>> Also if I forget about R391,R392,C119,R390 and just jumper the whole 
>>> thing straight from the INT Clock Output then it would work too.
>>
>> These do a similar function to C4, D2 and R11 in Yves' circuit. I 
>> would just use the original ARP parts and save the bother of 
>> replacing this section.
>
> What if I go straight from R391(ARP) into Yves ( pin12 of U2d's 
> Non-Inverting ) would that resolve my issue?

That is what I would try. I'm by no means the most knowledgable person 
on this list, so if someone else knows better please correct me!
Yves module does work with a square wave but this is converted to a 
trigger by C4, D2, R11 and U2d. You could also try bypassing R391 and 
take your trigger signal from the junction of C119 and R392.

James