MOTM

A collection of various Moog filters, and the soon upcoming MOTM-490 is at:

www.synthtech.com/misc/ap_test_moog.zip

these are 3 small MS Word documents. These are presented "as is" without explanation or
elaboration. Interpretation of the "meaning" of these graphs is up to the viewer. They mean a lot
to me, but may mean nothing to your cat.

Thanks to the folks that let me borrow these various filters.

Paul S.

No explanation required, Paul.  You are the engineer's engineer!

Sincerely and humbly,

Chub

I'm a touch confused.  (Gar, *that's* a surprise, right?)

Oddly, if you just look at the graphs, it looks like the Doepfer is most Moogly.  The MOTM vs. ModCan THD+N (what's N?) graph doesn't clearly indicate which line represents which filter (or I don't know how to read it), and neither line looks like the MOTM line in other graphs (no sharp dip at 5k, for example).  Also what's the magenta line in the 2nd graph in the freq_2 document (in which the MOTM line doesn't look like other MOTM lines either)?

Were all these filters fed *exactly* the same source?

Ultimately, though, lines don't mean as much as what your ears tell you, anyway.  :)

--PBr

-----Original Message-----
From: Paul Schreiber [mailto:synth1@...]
Sent: Tuesday, May 21, 2002 8:57 PM
To: MOTM listserv
Subject: [motm] Moog filter plots


A collection of various Moog filters, and the soon upcoming MOTM-490 is at:

www.synthtech.com/misc/ap_test_moog.zip

these are 3 small MS Word documents. These are presented "as is" without explanation or
elaboration. Interpretation of the "meaning" of these graphs is up to the viewer. They mean a lot
to me, but may mean nothing to your cat.

Thanks to the folks that let me borrow these various filters.

>
> Oddly, if you just look at the graphs, it looks like the Doepfer is most Moogly.  The MOTM vs.
ModCan THD+N (what's N?)

Noise

> graph doesn't clearly indicate which line represents which filter (or I don't know how to read
it),


Modcan on top, MOTM on the bottom


>and neither line looks like the MOTM line in other graphs (no sharp dip at 5k, for example).

This was due to setting the MOTM-490 to be as close to the gain/resonance/frequency response of
the Modcan as possible. This holds true for all the graphs.



> Also what's the magenta line in the 2nd graph in the freq_2 document (in which the MOTM line
doesn't look like other MOTM lines either)?

The technical term is "Paul hit the wrong icon." Or in Tandy-speak "The fault was a loose nut
behind the keyboard."

>
> Were all these filters fed *exactly* the same source?

Yep, a 0.000015% THD +N sine out of my Audio Precision at 1V RMS (about 3V pk-pk).

>
> Ultimately, though, lines don't mean as much as what your ears tell you, anyway.  :)
>
True, but I can "hear" these graphs as well :)

Paul S.

noise@... writes:

>>Oddly, if you just look at the graphs, it looks like the Doepfer is most 
Moogly. Ultimately, though, lines don't mean as much as what your ears tell 
you, anyway.<<

And to most peoples ears the Doepfer isn't as Moogy sounding as it should be.

-Elhardt

> >>Oddly, if you just look at the graphs, it looks like the Doepfer is most
> Moogly. Ultimately, though, lines don't mean as much as what your ears tell
> you, anyway.<<
>
> And to most peoples ears the Doepfer isn't as Moogy sounding as it should be.
>

I will say that the FFT shows similar *distortion* artifacts (the input to an FFT is a 1.000Khz
sine wave with harmonics down 152dB). However, that is not the "telling" graph :)

Paul S.