Archive of the former Yahoo!Groups mailing list: MOTM

Yea! Here are some AP plots of the MOTM-450 filter section.

www.synthtech.com/misc

it's a small 12K 2pg PDF file.

If you've heard of an 'elliptical response, but never seen on, now is your chance :) It's on the
HPF stage. Things to note:

I need to verify that on the Moog 907/914, the frequency indication is for the ∗center frequency∗
or the -3dB point. Looking at the graphs, it's the -3dB point. I'm not sure that's "accurate" or
not.

The particular circuit topology used is ∗very∗ low noise. Look at the noise floor on the FFT
plot! Its down over 130dB (in the nanovolt range).

I still have to "gain balance" the filters. Note the LPF is unity gain, the BP is like -15dB down
(around a gain of 1/6th), This is just resistor tweaking.

Next I'll add the 10 pots (groan) and make more pretty pictures. Yep, it's a Sat. night geekfest
(pathetic).

Paul S.