A quick update about my String Filter project
(
http://www.jhaible.heim.at/string_filter/jh_string_filter.html ):
Filter section of one board (20 channels) tested.
The new filter topology works great!
And trimming these filters works like a charm.
They are stable, with TL072 chips.
You can use 10% capacitors here, and still you have almost one turn of the
multiturn trimmers to walk along the peak of the BPF transfer function.
Still have to build the VC resonance and the Stereo Spread function, and the
on-board PSU. If this works, I'll order a second board to build a complete
40-band prototype.
JH.
Now Playing: Mike Oldfield, Ommadawn