[sdiy] Filter problems
jschwich53 at comcast.net
Sat Jan 27 22:33:57 CET 2018
Look at the Shruti state variable filter schematic. It's pretty much the
1) 3.6V zeners are used in Shruti verses 3.9V, not a problem.
2) Your R11 is 33K, Shurti it's 15K.
3) The BP out in the Shruti filter is feed back into the input (your U2B)
with a 330K resistor.
Have you put a meter/scope on FC to see what it is doing?
From: Synth-diy [mailto:synth-diy-bounces at synth-diy.org] On Behalf Of Tim
Sent: Saturday, January 27, 2018 8:28 AM
To: SYNTH DIY
Subject: [sdiy] Filter problems
Filters can be a pain. I've got one that is misbehaving. Here is a link
to the schematic:
At low CVs it filters fine, but as the freq cv hits around 2 volts the
behavior gets odd. I start seeing a rising DC bias on all the outputs.
At about 3 volts all the outputs rail positive.
Any help is appreciated. Thanks for playing!
timr at circuitabbey.com
Synth-diy mailing list
Synth-diy at synth-diy.org
More information about the Synth-diy