PSN-L Email List Message

Subject: RE: Preamp-Filter Modification
From: jmhannon@........
Date: Mon, 11 Sep 2000 08:26:13 -0500 (CDT)

I did a little reverse engineering on the A Loomis filter. It is a 4 pole
Butterworth filter with a 3dB cut off of 1.59 Hz. You can easily change it
to a 15.9 Hz 3dB cut off by changing the 4 1MEG resistors to 100K. Any
other frequency can be chosen by appropriate scaling of the 4 resistor
values. You might also want to look at Larry's 10 Hz filter at 

Jim Hannon


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Larry Cochrane <cochrane@..............>