Staying in London

[Tony Hardie-Bick]

Martin Naef wrote:
> Tony,
> 
> Tony Hardie-Bick wrote:
>> PS - just fitted your Stick with a final version of the filter circuit I've been 
>> working on (so now I have two identical instruments again).
> 
> Have you progressed it much since I've heard it last time?
> 
> Martin
> 

<sigh>

the concept I described worked... but I found that changing a resonant filter 
"instantaneously" created a chirp (ie, glitch) at the start of some notes. It 
took some iterations (and pcbs) before I discovered that if you make the attack 
time shorter than (or comparable to) any of the chirp cycles, the glitch 
diminishes, because the filter doesn't get time to ring....

anyway. notes from an electronic engineers handbook... I must say working in 
analogue has been much fun. really organic compared to digital.

and the current circuit *is* the final version ;)

Tony (HB)