MOTM

I have a question about the MOTM-300 sync feature.  (Not that I own one to
play with, just tossing about ideas in the knoggin.)  It's a pretty basic
question, really... how is it used?

My current concept of sync'ing oscillators is based on the Nord Modular
oscilators.  There are master oscillators with a sync out, and slave
oscilators with a sync in.  The slave oscillator's frequency is some
multiple of the master... 2x, 0.5x, 1.005x, etc.  The inputs and outputs are
clearly differentiated.

On the MOTM-300, however, the sync is marked "I/O".  How does it know which
oscillator is the master and the slave?  Do you plug the Sync I/O jacks into
each other, or you you send the oscillator outs to the sync in?  And what's
the functional difference between hard and soft syncing?  Or do I have
completely the wrong idea of what the sync feature does?

--PBr, blabbering again...

> From: "Brousseau, Paul E (Paul)" <PaulBr@...>
> 
> On the MOTM-300, however, the sync is marked "I/O".  How does it know
which
> oscillator is the master and the slave?  Do you plug the Sync I/O jacks
into
> each other, or you you send the oscillator outs to the sync in?  And
what's
> the functional difference between hard and soft syncing?  Or do I have
> completely the wrong idea of what the sync feature does?

Well, here is my take on it.  Basically, the sync I/O on the MOTM is the
ONLY place to connect sync input.  You then use the switch to select hard
or soft sync.  Soft sync is more what you described of the slave oscillator
being a multiple of the master oscillator.  Hard sync is another story.  A
few months back right after the 300 came out, there was a lot of discussion
in this subject and a minor modification was made to the soft sync
function.  Hard sync forces the slave oscillator to the same frequency as
the master, which can result in significant distortion of the slave
waveform, AND a very well recognizable sound.  Once you hear hard syncing,
you will say "oh yeah, I have heard that on <insert list of recordings
here>.

You can use a waveform output of the master oscillator as the signal source
to connect to your sync input of the slave oscillator.  However, you can
ALSO use the sync I/O jack as the output of that signal.  When using the
sync I/O as an output, you should set the sync switch to soft.  Using the
sync I/O as the source of your sync from your master allows you to not tie
up one of the waveforms (although I guess you could use a multiple).  I
find I always use the sync I/O as my output signal source from my master
osc.  I guess that will change when the micro-VCO comes out since it may
not have sync.  It will need to always be the master with the 300s getting
their sync source from one of the micro waveforms.

Now, one of the more experienced modular guys will have to speak to which
of the available waveforms makes the best sync source.

Larry (stooge still learning modular) Hendry

In a message dated 12/27/99 11:21:54 PM, jlarryh@... writes:

>Now, one of the more experienced modular guys will have to speak to which
>of the available waveforms makes the best sync source.

Where the hell is Bradley (Mr. Emu soft sync man) when you need him (or Crow 
or Doug Kraul for that matter -- Crow and Crawl? Wasn't that an old Motown 
hit by Howard , Fein, and Howard?)! I'm pretty sure hard sync happens ANYTIME 
you plug a rising edge waveform from one oscillator (a master oscillator) 
into the sync input of a second (slave) oscillator -- it doesn't matter 
whether the (input oscillator's) sync switch is in HARD or SOFT position. 
BTW, you can set the master VCO's sync switch to SOFT and it will output a 
pulse train which can be used as a hard sync source for the slave VCO, so you 
don't need a multiple.

I've never had a good understanding of soft sync since the only VCOs that I 
have which offer soft sync are my 3340 based VCOs and the panels they are in 
are unlegended, and I long ago for got which input was hard sync and which 
was soft. As I understand the MOTM soft sync, there is apparently no 
master/slave relationship. Any VCOs that are within 5% of resetting will be 
forced to reset but any outside this range will continue their normal period 
until they are within the 5% margin.

And let me second the recommendation of Horowitz and Hill's book "The Art of 
Electronics" which is a bit expensive but well worth it as both a text and a 
reference. The only book which I might recommend more is Hal Chamberlin's 
"Musical Applications of Microprocessors" which is out of print, but 
available from both Chamberlin (photocopies), and Jeff Dec who has scored 
several brand new copies, and sells them at what I believe to be a reasonable 
price -- I can give you his e-mail if you're interested. The first third of 
Chamberlin's book covers analog synths and interfacing with micros with 
schematics for VCOs, VCFs, and VCAs.


JB

> >Now, one of the more experienced modular guys will have to speak to which
> >of the available waveforms makes the best sync source.
>
> Where the hell is Bradley (Mr. Emu soft sync man) when you need
> him

Vacationing at home all this week not answering email and playing with my
new 320s, that's where!

Hard sync imposes the frequency of a "master" VCO onto a "slave" VCO by
forcing the slave to reset at the master's frequency. The well known
characteristic hard sync sound is achieved by listening to the slave output,
and tuning it much higher than the master. The master sets the basic pitch,
but the frequency of the slave determines the biting overtones present.
Sweeping the pitch of the slave also with an EG gives you that sound you
hear in the Cars' "I Love the Nightlife Baby".

Soft sync is a much more gentle means of drawing the pitch of 2 or more VCOs
together so that they don't beat in frequency, without fundamentally
altering their sound. Just makes them play in perfect tune. There is no
master - slave relationship.

The 300s are set up like this: patch all VCOs to be synced together at their
sync jacks. If you set all sync switches to soft, you get soft sync. If you
switch one VCO to hard, it becomes a master and you get hard sync. If you
switch every VCO to hard, you don't get any sync because none of them are
"listening" to each other.

BTW, I had one of those small proud moments when I opened my "Art of
Electronics" book yesterday and discovered the identical circuit for a flash
ADC that I had come up with independently a few weeks ago. Not terribly
impressive maybe, but it's nice to know that a few brain cells remain from
when I was a practicing EE 9 years ago.

Moe

> From: Dave Bradley <daveb@...>
> 
> Vacationing at home all this week not answering email
> and playing with my new 320s, that's where!

Good plan !!

> The 300s are set up like this: patch all VCOs to be synced
> together at their sync jacks. If you set all sync switches
> to soft, you get soft sync. If you switch one VCO to hard, 
> it becomes a master and you get hard sync. If you
> switch every VCO to hard, you don't get any sync 
> because none of them are "listening" to each other.

Great explanation Dave.  However, I am putting the slave osc switch on hard
sync.  Am I violating the ever-so-evasive rules of modular?

Larry H