[sdiy] Modding the RS200

[Peter Grenader]

I just wrote a reply to this to the AS list, so possibly it is the same
gentleman but I agree with what Tony is saying here wholeheartedly, and
suggested running the counter outs from the AS board threw a 4050 (actually,
two of them) before any additional new pots/summers, etc.

The problem isn't so much the pots themselves as their pull is controlled
and minimal, the major culprit is the manner in which the stage gate outs
are conditioned as without proper buffering, they extend the digital
counter's load directly to the outside world.

P

Tony Allgoodwrote:

>> and at first sight it looks like I can add extra channels with or
> without slew quite easily to it just by connecting more knob boards
> to the data header ...
> 
> I think you probably could, but you would want to watch the load caused
> by the additional pots on the outputs of the sequential driver. Maybe
> you could buffer the digital signals that drive the existing pots before
> putting any extra load on it.
> 
> BTW: I have just had to service a PPG 100 sequencer from the mid 1970s.
> Its truly awful. 4000 CMOS (vdd = 15V, Vss = 0V) being driven by bipolar
> analogue signals all over the place. I don't think it ever worked
> properly as new.
> 
> And it had a Moog ladder filter in it, curiously named 104!
> 
> Regards,
> 
> Tony Allgood                       Penrith, Cumbria, England
> 
> Oakley Sound Systems                     www.oakleysound.com
> Modular Synthesisers        www.oakleysound.com/projects.htm
> 
> 
>