Roland System 700 709 sample and hold clone
It samples! It holds! Here’s an aggravating demo.
We’re into the area of circuits that I should have probably just built on stripboards, but anyway.
IC1 is a TA7504M in the service manual, I just used a 741. I even replicated the legs-in-the-air arrangement for the junction of Q3/C9/IC2 pin 3 as detailed in the service manual, presumably meant to minimise leakage.
The schematic in the service manual didn’t need any corrections, it works fine as it is.
Just now looking at the service manuals I realise the 100m version looks more fun as it includes a slew – if you were looking for one to do, maybe try that one.
I included the 716 mixer as on the original, but I’ve not got round to making that up yet (probably ‘cos it’s not going to be very exciting).
Another board done, onto the next…