MOTM

how similar is the motm cs80 filter to the filter used in the lesser
cs models - cs5/15/etc?

tx

Hi.

I recently engineered a record for a band that used LOTS of cs-30 and cs-15. The filters
were very different from the cs-80, which I play frequently.

I don't know the topology, but they are more resonant and moog-like. They are "lesser" in
size, but I found them quite capable.

The motm-480 is a very accurate reinvention of the cs-80 filter, but is also capable of a
much wider spectrum of sounds due to its modular format.

Max

--- In motm@yahoogroups.com, Jason Proctor <jason@r...> wrote:
> how similar is the motm cs80 filter to the filter used in the lesser
> cs models - cs5/15/etc?
>
> tx

For the CS-15: the same basic filter circuit is used here as in the
CS-80, but there is only one filter per "channel" that is switch
selected to be HP, BP or LP instead of the 80's hardwired HP->LP pairing.
Like the CS-80, the CS-15 has two voice channels, just one pair instead of
eight. There are some other differences in the EG routing, too.

For the CS-30 the filters are very similar to the way they're
implemented in the CS-15. The main difference in the CS-30 (vs. the
CS-15) are that the filter EG is back (3 EGs total) and a sequencer is
also installed. The key filter difference is that the filters can be
patched in series.

An MOTM-480 is two 12dB/octave filters with HP/BP/LP simultaneously
available internally, and with a spare 1U module panel and several 1/4"
jacks the remaining ones could be brought out.

480 is like this:

+---> BP out
|
(HPF) | (LPF) (HPF) LPF
inputs--+---+---+ /---+---+---+---> LP out
| BPF | (BPF)
| |
+-----------/

(filter #1) (filter #2)


The "BP out" isn't on a CS-80 voice, it was added because there was
panel space and it is a useful signal. However, it is simple enough to
bring the four remaining (HPF#1)(LPF#1)(HPF#2)(BPF#2) signals out to
jacks, and it is also (relatively) easy to use a switched jack to break
the filter#1->filter#2 path for both audio in and CV in, creating two
completely independent filters.

Crow
/**/

On Thu, 16 Dec 2004, rreprobate wrote:

> I recently engineered a record for a band that used LOTS of cs-30 and
> cs-15. The filters were very different from the cs-80, which I play
> frequently.
>
> I don't know the topology, but they are more resonant and moog-like.
> They are "lesser" in size, but I found them quite capable.
>
> The motm-480 is a very accurate reinvention of the cs-80 filter, but is
> also capable of a much wider spectrum of sounds due to its modular
> format.
>
> Max

That's interesting! Now that I know this about the MOTM-480, I may have
to buy a kit and put a custom panel on it.

-Richard Brewster (buying a bigger house to make more room for MOTM)

The Old Crow wrote:

> An MOTM-480 is two 12dB/octave filters with HP/BP/LP simultaneously
>available internally, and with a spare 1U module panel and several 1/4"
>jacks the remaining ones could be brought out.
>
> 480 is like this:
>
> +---> BP out
> |
> (HPF) | (LPF) (HPF) LPF
> inputs--+---+---+ /---+---+---+---> LP out
> | BPF | (BPF)
> | |
> +-----------/
>
> (filter #1) (filter #2)
>
>
> The "BP out" isn't on a CS-80 voice, it was added because there was
>panel space and it is a useful signal. However, it is simple enough to
>bring the four remaining (HPF#1)(LPF#1)(HPF#2)(BPF#2) signals out to
>jacks, and it is also (relatively) easy to use a switched jack to break
>the filter#1->filter#2 path for both audio in and CV in, creating two
>completely independent filters.
>
>Crow
>
>
>
>