I'm from an Emu modular background, so you'll probably get tired of me
suggesting things from that point of view in the coming months. However, Emu
DID have an elegant modular sequencer system which we could steal a lot of
ideas from, and improve on. BTW, I have a 1978 Emu Technical catalog that is
a wonderful resource for info about their entire line. If there is enough
interest, I could maybe find some time to scan and post the sequencer pages.
For sequencing newcomers, I've included a discussion below on uses of analog
sequencing. Forgive me if I'm preaching to the choir<g>!
Someone mentioned the Emu 4060 keyboard sequencer in a discussion about "why
analog sequencing?" I own one now (which is shortly going to Dave Kean's Emu
synth museum), and also worked with a maxed out 4060 w/ disk drive in a very
large electronic music studio years ago. You used these types of
"recording" devices like you would a MIDI sequencer today - basically play
stuff in real time and build up complexity in multiple recording passes.
This was a system capable of 16 tracks back when synthesizers had barely
gone polyphonic! Because each track was output to a separate signal chain,
you had intimate control over the sound of each channel. Sounds like a
modern multitimbral synth, right? I remember sequencing some Aaron Copeland
stuff in the late 70's on analogs that would fool you into thinking it was
an orchestra. The ability to edit notes on this system was present in a
primitive fashion in a special software version commissioned by Patrick
Gleeson (prominent 70's synthesist), but was nowhere near the level of even
the most rudimentary software MIDI sequencer today. The 4060 type of
sequencer is IMHO obsolete today.
However, the analog step sequencer is a different kind of beast. Yes, you
can use it for manually generating short phrases, but it's not the tool you
would choose to do things that were better played in from a keyboard. Think
of it as a pattern generator, which can control pitch, yes, but also
anything else. A flexible system will have inputs and state outputs to allow
it to be self modifying in interesting ways, probablistic and otherwise.
Clock it at high speed and you have wavetable synthesis. Set up 3 filters
under sequence control, slap some lag on the step outputs, and you have
moving formants. Etc etc...
Back to MOAS, here for reference is how the Emu modular system was broken
out. I'm doing this from memory, so I may make a mistake or two:
1. Voltage Controlled Clock module. Flexible, includes PWM, and can be gated
to 2 different outputs. Has an inhibit input.
2. 8 Stage Address generator module. No pots. This is the counter / shift
register piece. Clock Up, Clock Down inputs. Each stage has a gate output, a
Set input that forces that stage active (very important IMO), a lamp
indicating when the stage is active, and a manual Set pushbutton, again to
force that stage active. You can force any stage to follow another by
patching its Set input from the gate out of the other. Multiple address
generators can be chained together by using a Carry output and a Borrow
input (note the counter terminology). The current state is output in binary
form on 3 jacks (binary 1-8 == 000-111). Interestingly, it has no random
stage select capability like we see in other designs.
3. 8x4 Pot Matrix module. Has 3 jack binary input to connect to address
generator. 1 output per row, and an inhibit input forces all voltage outputs
to zero.
4. Misc logic modules - OR gates, inverters, etc. Quad analog switch module,
can be used to convert 8x4 voltage matrix to 32x1.
5. Digital memory module. 256 locations (I think), each can record a voltage
and a few gate signals. Has a clock input and a record enable input.
6. Digital address programmer. Connected to one or more digital memory
modules, has an octal address display (awkward by today's standards). You
set the address you want to program, enable record on the memory module you
want, input the voltages and gates to the programmer, and blast it in.
Well, I've blathered long enough - I'll leave the connection possibilities
to your imagination.
Dave Bradley
Principal Software Engineer
Engineering Animation, Inc.
daveb@... > >Paul Schreiber wrote:
> >> Here is a brief outline of the direction I am going:
> >>
> >> 1) It's modular
> >> 2) Has full MIDI control, but all outputs are analog
> >> 3) Patch memory
> >> 4) I can be BIG. I mean ∗REALLY BIG∗ - 256 stages x 64 rows
> >> 5) The modules are tied to a local LAN than reconfigures the
> modules, ie
> >> Plug-&-Play.
> >> 6) This being MOTM and all, no cheesy pots. We're talking
> optical encoders,
> >> baby!
> >> 7) uP will be in C programming, with "open source code" posted on the
> >> website.