MOTM

MAM is making drum modules.
What you expect from an analogue/digital drum machine, but
in a big rackmount enclosure with many parameters for
each voice.

JH.


-----Urspr\ufffdngliche Nachricht-----
Von: <mark@...>
An: Tkacs, Ken <ken.tkacs@...>
Cc: <motm@yahoogroups.com>
Gesendet: Freitag, 19. Oktober 2001 18:11
Betreff: Re: FW: [motm] Re: Drum modules..


> At 11:35 AM -0400 10/19/01, Tkacs, Ken wrote:
> >
> >A lot of early analog drum circuits used cheapie filters with high
> >resonance. The effect you're describing is a damped oscillation caused by
> >the filter 'ringing,' and by tweaking the filter component values, you
can
> >get all sorts of drum sounds.
> >
> >I think PAIA had/has a board that lets you play with this kind of thing.
>
> Exactly :)  Roland calls it a "periodic damping oscillation".  The circuit
> looks like a filter (in the more general sense of the word -- it's not a
> VCF) as it has an RC network in the feedback path of an op-amp.  It has
two
> parallel elements in the feedback path: a resistor; and a T-network
> composed of two caps (parallel to the afformentioned resistor, and in
> series to each other) with a second resistor between the two caps going to
> ground.
>
> I wouldn't want MOTM to make anything "cheapie"!!  However, I'm thinking
> this damped oscillation idea could be incorporated into a more
> sophisticated  "trigger to audio converter".  Perhaps 1U, with trigger in,
> audio out, and a couple of VC inputs.
>
> I'm no EE, I'm just throwing around half-baked ideas :)
>
> > For drums, the TR-808 uses a "bridged T-network" in order to create a
> >waveform similar to an oscillator decaying in amplitude.  Rather than
using
> >the trigger to trigger EG's controlling separate VCO's and VCA's as in
the
> >606 and 909, it seems the trigger itself is transformed into the sound.
In
> >my limited understanding, it's like a VCO that runs out of steam.  Like
the
> >skin of a drum, it oscillates after being hit, then tapers off into
> >silence.  For the 808 toms, this circuit is modified with diodes such
that
> >the frequency decays as well.  Perhaps this technology could be rolled
into
> >a  MOTM module with increased flexibility such that it could produce more
> >than just drum sounds.
>
>
>
>
>
>
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