Any dual op amp will do for that circuit. TL072 is fine.
For more MOTM-800 mods see:
http://www.tellun.com/motm/diy/db800/DB-800.htmlhttp://pugix.com/synth/motm-800-adsr-envelope-generator/Richard Brewster
Koos Fockens wrote:
> Seeing the blinky LED's on Robert Rich's MOTM-800's in the demo video, made me want
> these too on my 800's, and I found the mod for this on Stooge Moe's website. Before I start
> to buy parts etc, I'd like to know which dual opamp is best suited for this? I realize almost
> anything will do, but I want to make sure I get something decent enough not to cause
> problems or interference, noise, hiss etc.
>
> Cheers :-)
>
> Koos
>
>