200e

> you could say that the second case is true, in that there is a
> computer in there with realtime memory. in the 250e, it is
> continuously updating this realtime memory (and the cv output) based
> on the knob position of the *current stage,* or based on something
> else like an external cv input if it's in that mode.

OK, this makes sense, of course.  But as I only care about the voltage
as each stage is reached, this is a moot point: presumably for normal
function this updating must be pretty damn quick after the stage is
addressed.


> the current behavior of the 250e is that it's supposed to read the
> physical knob positions when it powers up, but it's slightly buggy
> because of a conflict with the interpolation algorithm (which i'll get
> to in a second) and because the knobs aren't all scanned at once but
> rather at each stage of the sequence (which allows each knob to be
> scanned at a much faster update rate). so it's tricky, and right now
> the accuracy at startup depends on the difference between the stored
> values and the phyiscal values. one of our programmers is working very
> hard on making it better. at the moment i'm afraid the best way to get
> consistent behavior is to use the thing in conjunction with a 225.
> it's somewhat of a trade-off, but i personally consider it more
> convenient than old drifty analog sequencers.

OK, but if the knobs haven't moved at all since I set the stored
values, the interpolated value at runtime will presumably be the same
as both the knob position and the stored value (if x=y and
z=ax+(1-a)y, where 0<a<=1, then z=x=y).  Or is there a resolution
issue here that I haven't thought of that could throw things off? 

To be honest I don't really care about multiple presets: the only
reasons I would get a 225e would be (i) syncing to MIDI clock, (ii)
making use of MIDI performance interfaces, and (iii) remembering the
sequencer settings. From what you've said, I *think* I can still wait
with the 225 until I upgrade to the 12-cabinet next year.

 
> a behavior that i maybe like better is to have the 250e alwasy load
> preset zero at startup, so you can have some control over the
> "default" behavior, and to make it amenable to the autonomous preset
> storage behavior that we implemented in the 210, 291 and others. even
> this is kind of difficult because of the realtime updating that i
> mentioned before, but fixing it is a high priority.

Not sure I like the sound of that (for me, right now).  That would
REALLY force you to have a 225e.

> 
> > This makes me think of a more general problem with discrepancy between
> > pot positions and stored values in the 200e as a whole: how is the
> > conflict resolved? If you touch a knob after loading a preset, does
> > the value jump to the new pot position, or is there a 'latch' mode
> > like on some other synths (not sure which is better / worse, I don't
> > really like either)?
> 
> neither do we. the 259e was the first module in the series and it used
> a latch, but don has since designed a quite elegant algorithm to
> smoothly interpolate between the physical knob positions and the
> stored parameter values at all times. basically the knob range is
> rescaled until its position matches the stored position, at which
> point it resumes its default scaling with no perceivable transition.
> this is true for nrealy all of the knobs in the system.
> 

Now that sounds cool.  Never encountered that before.  So let me get
this straight: suppose the stored value is 0 (min) and knob is at 10
(max), then when you turn the knob, nothing will happen until you hit
zero.  Whereas, if stored is at 5 (midpoint) and knob is at 10, when
you turn the knob, you'll start decreasing from 5 at a rate that is
constantly changing until (at some point), you 'catch up' and knob
position becomes absolute (rather than relative).  I guess the only
problem is if the knob is at 10 you can't increase above 5 without
going down a little first (in fact, do you have to pass through the 5
position to be able to go up from there?).  Have I got that right?  In
practice I'm sure it works well ... 


> > Is there a way to force a module to use its front panel settings
> > rather than whatever is stored in patch memory (I can imagine, for
> > example, pressing and holding 'remote enable' for a few seconds, to
> > toggle between the front panel values and the stored values).
> 
> that's a nice idea. the remote enable button is already overloaded but
> it's a nice idea. currently you can make sure you are reading the full
> range of each knob by sweeping it between its extremes.
> 
> forcing each module to re-scan its panel with a switch might be cool,
> but it also might be less useful than you think. the patch recall is
> really kind of magical, and all knobs always respond smoothly and
> pretty much as expected.
> 

I can believe that.  On the other hand I use this function all the
time with my Creamware Minimax. 

> > Sorry for all these questions, I just want to make sure I order
> > exactly what I need. By the way, quantization doesn't really bother
> > me: many of my other analogue sequencers don't even have it. As long
> > as you can adjust the sequencer CV's finely enough to hit the sweet
> > spot, I don't care.
> 
> cool. accurate pitch is of course a crucial and difficult problem
> because of the incredible resolution of the ear in the frequency
> domain. the buchla solution has always been to allow arbitrary scaling
> of frequency modulators. this means that it is possible to trade range
> for accuracy at will, or vice versa. i think it is still a good system
> that works quite well, and has managed to accomodate a wide variety of
> technical limitations and tolerances in the last 35 years.
> 
> i might as well freely admit that the 250e is not an analog sequencer,
> it has a digital brain and an analog-style interface layer. in some
> respects its character is noticeable, but in other respects it kind of
> transcends such discriminations with a truly freaky set of
> capabilities...
> 

Oh I know it's not analogue.  Never made much sense to me to use
analogue for stored voltages anyway.  What I do care about is
directness of the interface, and being able to control it with CVs and
gates.



> > Thanks a lot!
> 
> no prob
> 
> -eb
> 
> > --- In 200e@yahoogroups.com, "ezra buchla" <ezra.buchla@> wrote:
> >>
> >> that's right. getting autonomous preset storage in the 250e is a
> >> priority but it's proven difficult. next firmware rev.
> >>
> >> fort now, you must use a 225.
> >>
> >> On Wed, Aug 20, 2008 at 1:24 AM, JB <ringmodulator@> wrote:
> >> > This is something i know Ezra has been working on implementing
in all
> >> > modules, but im not sure if the 250 has this feature yet. I would
> >> > recommend getting the 225e though, being able to switch presets is
> >> > very valuable if you plan to use the system live, its a great
feature,
> >> > i use it all the time.
> >> >
> >> > 2008/8/20 kkonkkrete <kkonkkrete@>:
> >> >
> >> >>
> >> >> How much does the Arbitrary Function Generator remember at power
> > down?
> >> >> If you don't have a 225e to store the settings, does the 250e
recall
> >> >> all data for the current settings, or do you have to reprogram it
> >> >> every time you power up (or load the program from the 225e if you
> > have
> >> >> one)?
> >> >>
> >> >> Sorry for this basic question ...
> >> >>
> >> >> Thanks,
> >> >> KKonkkrete
> >> >>
> >> >>
> >> >> ------------------------------------
> >> >>
> >> >> Yahoo! Groups Links
> >> >>
> >> >>
> >> >>
> >> >>
> >> >
> >> >
> >>
> >
> >
>