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255

2008-06-17 by JB

I have been thinking (again) about the 255. On the Buchla Modular list
Reed wrote the following a couple of years ago:

"Sorry to be so pro-255, but it's one heck of a useful module, or, as
David Kean calls it, "a Swiss Army knife." Fire a pulse into one of
those holes and it's an envelope generator. With any Buchla stuff
it's good to have extra attenuators & inverters lying around (and if
you have any 100-series modules it's a godsend). Not to mention the
luxury of being able to pepper the tiniest soupcon of lag to smooth
clicks out of certain patches. I wish it had Schmitt triggers,
though."

From this description it sounds like a very useful module; attenuation
and inversion of CV, extra envelopes when 281 is occupied with other
tasks, lag.

I assume the following:

1. With multiplier knob at 12 o'clock no CV is passed through.
2. With multiplier knob at fully CW input and output is identical
(assuming no lag applied)
3. With multiplier knob at fully CCW output is a fully inverted
version of input* (assuming no lag applied)
4. +Lag is lag on rising CV, -Lag is lag on falling CV.
5. When lag knobs are set fully CCW no lag at all is applied to CV out.

*) I assume inverted in this case means voltages goes below zero. How
does 200e modules react to negative voltage? The 256e seems to have a
different form of inversion where i believe the voltage is inverted
within the positive range.

Am i right? Can someone who has one please reply?

(If there are enough "yes" answers to these statements i might be
interested in trading a 259e for one of these + cash, anyone
interested)

Thanks
Johan

Re: [200e] 255

2008-06-17 by ezra buchla

yeah, inversion is funny.

let x = input in [0, 10]
and y = knob value in [-1, 1]
z = output

if y >= 0, z = y * x
if y < 0, z = (y * x) - (y * 10)

or something like that.

this "inversion" means that the negative range of the knob, with no
input, produces whatever 0-10v output you like, with lag: handy.

also, the lag doesn't ever go completely down to zero, but gets very short.

it's a fully analog module, so there is some variation in the
components. different stages might have slightly different lag times
or scaling.

everything else you say is true.

i should point out that when reed talks about using a lagged pulse as
an envelope, he's probably using an old 200 series pulse. the 200e
pulses are so short that they are attentuated by the minimal upward
lag in the 255. it is still a useful thing if you need a quick,
attenuated percussive envelope (like for pitch on a "kick drum" patch)

-eb

Show quoted textHide quoted text

On Tue, Jun 17, 2008 at 4:42 AM, JB <ringmodulator@gmail.com> wrote:
> I have been thinking (again) about the 255. On the Buchla Modular list
> Reed wrote the following a couple of years ago:
>
> "Sorry to be so pro-255, but it's one heck of a useful module, or, as
> David Kean calls it, "a Swiss Army knife." Fire a pulse into one of
> those holes and it's an envelope generator. With any Buchla stuff
> it's good to have extra attenuators & inverters lying around (and if
> you have any 100-series modules it's a godsend). Not to mention the
> luxury of being able to pepper the tiniest soupcon of lag to smooth
> clicks out of certain patches. I wish it had Schmitt triggers,
> though."
>
> From this description it sounds like a very useful module; attenuation
> and inversion of CV, extra envelopes when 281 is occupied with other
> tasks, lag.
>
> I assume the following:
>
> 1. With multiplier knob at 12 o'clock no CV is passed through.
> 2. With multiplier knob at fully CW input and output is identical
> (assuming no lag applied)
> 3. With multiplier knob at fully CCW output is a fully inverted
> version of input* (assuming no lag applied)
> 4. +Lag is lag on rising CV, -Lag is lag on falling CV.
> 5. When lag knobs are set fully CCW no lag at all is applied to CV out.
>
> *) I assume inverted in this case means voltages goes below zero. How
> does 200e modules react to negative voltage? The 256e seems to have a
> different form of inversion where i believe the voltage is inverted
> within the positive range.
>
> Am i right? Can someone who has one please reply?
>
> (If there are enough "yes" answers to these statements i might be
> interested in trading a 259e for one of these + cash, anyone
> interested)
>
> Thanks
> Johan
>
>

Re: [200e] 255

2008-06-17 by JB

2008/6/17 ezra buchla <ezra.buchla@gmail.com>:
> this "inversion" means that the negative range of the knob, with no
> input, produces whatever 0-10v output you like, with lag: handy.

Interesting, could be useful.

> also, the lag doesn't ever go completely down to zero, but gets very short.

Is that short as in "almost inaudible short" or just short when
applied to pitch for instance?

> everything else you say is true.

Thanks for clearing it up Ezra.

> i should point out that when reed talks about using a lagged pulse as
> an envelope, he's probably using an old 200 series pulse. the 200e
> pulses are so short that they are attentuated by the minimal upward
> lag in the 255. it is still a useful thing if you need a quick,
> attenuated percussive envelope (like for pitch on a "kick drum" patch)

Ok, good to know. I won't expect that to work then. If it still does
in some sense it will be a bonus :)

Show quoted textHide quoted text

> -eb
>
> On Tue, Jun 17, 2008 at 4:42 AM, JB <ringmodulator@gmail.com> wrote:
>> I have been thinking (again) about the 255. On the Buchla Modular list
>> Reed wrote the following a couple of years ago:
>>
>> "Sorry to be so pro-255, but it's one heck of a useful module, or, as
>> David Kean calls it, "a Swiss Army knife." Fire a pulse into one of
>> those holes and it's an envelope generator. With any Buchla stuff
>> it's good to have extra attenuators & inverters lying around (and if
>> you have any 100-series modules it's a godsend). Not to mention the
>> luxury of being able to pepper the tiniest soupcon of lag to smooth
>> clicks out of certain patches. I wish it had Schmitt triggers,
>> though."
>>
>> From this description it sounds like a very useful module; attenuation
>> and inversion of CV, extra envelopes when 281 is occupied with other
>> tasks, lag.
>>
>> I assume the following:
>>
>> 1. With multiplier knob at 12 o'clock no CV is passed through.
>> 2. With multiplier knob at fully CW input and output is identical
>> (assuming no lag applied)
>> 3. With multiplier knob at fully CCW output is a fully inverted
>> version of input* (assuming no lag applied)
>> 4. +Lag is lag on rising CV, -Lag is lag on falling CV.
>> 5. When lag knobs are set fully CCW no lag at all is applied to CV out.
>>
>> *) I assume inverted in this case means voltages goes below zero. How
>> does 200e modules react to negative voltage? The 256e seems to have a
>> different form of inversion where i believe the voltage is inverted
>> within the positive range.
>>
>> Am i right? Can someone who has one please reply?
>>
>> (If there are enough "yes" answers to these statements i might be
>> interested in trading a 259e for one of these + cash, anyone
>> interested)
>>
>> Thanks
>> Johan
>>
>>
>
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