[sdiy] Arp Quartet ADSR issues

[Adam (synthDIY)]

> On 5 Aug 2024, at 6:45 PM, Ben Walker <ben at audio.computer> wrote:
> 
>> Are you saying that the presence of the keyboard gate voltage is determined by which sound group you select from the front panel?
> Yep! And on some sounds the keyboard gate is fed a square wave. That seems intentional, but the low voltage on some sounds less so.

Ha!
The square wave kybrd gate thing reminds me of the "REPEAT" option in my old miniKorg 700 - designed to replicate the sound of mandolins,  etc!!! Cos that's what you wanted a monosynth to do back in 1974...
Some of the schematics remind me also of my SH2000 - e.g. the "staircase" wave forms associated with the ADSR.
Probably a similar vintage.
As Peter says, there could easily be a lot of bad joints in this thing.
My SH2000 gave me a lot of grief until I finally bit the bullet and laboriously re-flowed every joint on the main board... and then voila! 



https://mezzoauto.blogspot.com/2019/05/roland-sh-2000.html
Roland SH-2000
mezzoauto.blogspot.com
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