Yahoo Groups archive

MOTM

Index last updated: 2026-04-28 23:35 UTC

Thread

String Filter PCB progress

String Filter PCB progress

2008-04-05 by JH.

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

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.