Some corrections -
The Ken Stone ASR does not require a "pulse out" to daisychain ASRs
together.
The "Pulse Out" was simply the only possible way to get the ripple-
effect ASR to work. Each cell in the chain is transferred to the next
in succession. Each voltage therefore is passed between as many cells
as there are steps, losing accuracy along the way.
In the Ken Stone unit, each incoming voltage is stored in a single
cell for for the duraction of its life. The only time it is ever re-
sampled would be in the case of daisy-chaining, as it moves from one
unit to the next. There is no Pulse Out - because it is not needed.
Instead all voltages are effectively processed at exactly the same
time - achieved simply by having one more cell than outputs. So to
daisychain the Ken Stone ones, they simply run from the exact same
pulse source.
I have been told that the Ken Stone one, when using LM3140 instead of
the suggested LF356, and with a couple of other minor parts changes,
rivals the MOTM sample and hold for stability.
As for the difference between old and modern genuine Serge ASRs, I
expect the difference is merely component quality. Old Serges used a
lot of surplus parts, ceramic capacitors etc. I very much doubt the
circuit itself has changed, other than perhaps the addition of a
couple of bypass capacitors across the power supply rails.
--- In SergeModular@yahoogroups.com, Skot Wiedmann
<computer_jones@...> wrote:
______________
The Ken Stone ASR does not require a "pulse out" to daisychain ASRs
together.
The "Pulse Out" was simply the only possible way to get the ripple-
effect ASR to work. Each cell in the chain is transferred to the next
in succession. Each voltage therefore is passed between as many cells
as there are steps, losing accuracy along the way.
In the Ken Stone unit, each incoming voltage is stored in a single
cell for for the duraction of its life. The only time it is ever re-
sampled would be in the case of daisy-chaining, as it moves from one
unit to the next. There is no Pulse Out - because it is not needed.
Instead all voltages are effectively processed at exactly the same
time - achieved simply by having one more cell than outputs. So to
daisychain the Ken Stone ones, they simply run from the exact same
pulse source.
I have been told that the Ken Stone one, when using LM3140 instead of
the suggested LF356, and with a couple of other minor parts changes,
rivals the MOTM sample and hold for stability.
As for the difference between old and modern genuine Serge ASRs, I
expect the difference is merely component quality. Old Serges used a
lot of surplus parts, ceramic capacitors etc. I very much doubt the
circuit itself has changed, other than perhaps the addition of a
couple of bypass capacitors across the power supply rails.
--- In SergeModular@yahoogroups.com, Skot Wiedmann
<computer_jones@...> wrote:
>______________________________________________________________________
> just some thoughts concerning ASR's
>
> although the ken stone design is a clone of the
> function of the serge unit, there are some significant
> differences that are of note. one aspect of sample
> and hold devices is that they droop over time, that
> is, the hold is not infinite. the modern serge ASR
> has very good droop characteristics. the ken stone
> unit is actually designed to amplify the droop. this
> is an attempt to compensate for the limitations of the
> cheap multiplexer chips that he is using. with this
> design you have the choice of limited voltage range,
> or amplified droop. the modern serge design does not
> have these limitations. admittedly these limitations
> do not affect simple patches where a 5 volt lfo or
> similar is sampled, but when mixing various voltage
> sources, or playing a wide range of pitches from a
> keyboard, this can come into play. depending on your
> use of these modules, the similarities and differences
> in performance may be more or less evident. also if
> you replace a real serge ASR with the ken stone one,
> you will loose the "pulse out" which allows you to
> chain multiple units together for longer shift
> registers.
>
>
> --- Fernando de Izuzquiza <fdi@...> wrote:
>
> > Hi Bakis, it would be extremely difficult to find
> > Serge schematics.
> > Since it is functionally identical (and seem to have
> > better performance) this would be a
> > very good option:
> > http://www.cgs.synth.net/modules/cgs34_asr.html
> > The board is 6'' long, as original Serge's
> >
> > Fernando
> >
> >
> > --- In SergeModular@yahoogroups.com, Bakis Sirros
> > <synth_freak_2000@> wrote:
> > >
> > > hello,
> > > i'd like to find the schematics for a Serge dual
> > > analog shift register (early 80's module). i need
> > > these to give them to my tech to repair the second
> > > unit of a dual ASR module i have. in this module,
> > only
> > > the first unit works and also the aux pulse out of
> > the
> > > first unit seems not to work.
> > > any help please?
> > > thank you very much in advance,
> > > best regards, :-)
> > > Bakis.
> >
> >
>
>
>
>
>
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