[sdiy] Expo converters, lin log etc.

[Paul Perry]

I've seen a hell of a lot of electronic analog
math circuits - this was serious cutting edge stuff
before computers got small & fast - and as far as
I know, if you want  a really wide range (6 or more 
octaves) and fast response (into audio range) and
sufficient accuracy for music applications, then
transistors is it.
I personally would like to see a micro based 
solution - I think it is probably just doable - but
note that under some circumstances there might be 
stepping artifacts unless ther eis a very high res 
D to A converter and A to D converter (not cheap when
DC guaranteed!!) & it isn't (I think) going to be 
easy to get the fastest response from it.
I'd be interested to hear from the analog ASIC 
guys on this!
All uin all, the musical exponential current converter 
is a high point of analog design.
Of ANY design, some would say.

paul perry melbourne australia

----- Original Message ----- 
>From: "Karl Ekdahl" 
>For me to fully understand this it'd be intersting to
>create a fully "mathematical" circuit that performs
>expo-conversion using purely mathematical building
>blocks, i.e. something that does not rely on
>transistor parameters i don't understand etc. Is this
>possible?