Re: BeatSync (was vortex info)

[Anthony Bowyer-Lowe <anthony@amudarya.demon.co.uk>]

>The question is about the type of clock generated by old analog
>arpeggiators and sequencers, from before midi. Does it send a pulse each
>beat? A pulse at each bar? At the beginning of the sequence? Or does it
>send many pulses for each beat, the way midi clock works?


Okay people...

Well, sync24 is the most common vintage method of synchronising analogue
equipment, as found on old drum machines (Roland TR808, TR606) and
synths/sequencers (eg Roland MC-202).

As it's name suggests, it consists of 24 voltage pulses (normally +5v, for
around 5ms) per quarter note. Yup, just like midi clock...

Also found is sync48, which is used by some old Korg drum machines, and
consists of 48 pulses per quarter note. I just sync my Korg DDM220 to 
standard
Roland sync24 (also known as Din Sync as it uses a 5 pin DIN plug, easily
confused with midi), and program the Korg in double time... To confuse
matters further, sync48 also uses a 5 pin Din plug.

Most analogue sequencers and arpeggiators just have a trigger in/out which
advance the sequence by one step. Usually just a positive going pulse 
(+5v),
although some equipment used a negative going pulse (-5v), or a short to
ground (S-Trig).

>It would be fun to figure out how to sync the old analog stuff up to 
>modern
>loopers.

I figure it'd be a great project (for people like us) to build a little
sync utility box. It'd have a bunch of converters to convert between the
varying types of pulse, and a clock divider which output a trigger every
x input pulses...

More information of this kind can be found through the analogue heaven
mailing list (www.hyperreal.com/music/machines/) or synth-diy.

Questions?

Analogue freak, and budding looper,
ynohtnA.
--
Anthony Bowyer-Lowe.
The Essence Of Anthony.
http://www.amudarya.demon.co.uk/