MOTM

OK, I'm not a Buchla expert, but I can see an immediate reason it was hard to do "Carlos music"
on them.

The VCOs have NO straight 1V/Oct inputs! On the dual 258s, there are 2 exponential FM ins (both
on reversing attentuators, with a coarse AND a fine adjustment) and on the linear FM. just a
straight attenuator.

I suppose the thinking was to use the combination of Coarse/Fine attenuators to get to 1V/Oct,
but this is a doomed operation.

The actual circuitry is a straight-forward 726 heater expo converter, a hand selected
hi-frequency track resistor (about 3M) with LM741 CV mixers (ugh).

It's obvious from looking at 1/2 of the modules that Buchla loved the military surplus stores :)
The boards are a hodge-podge of decent 1% RN resistors mixed with carbon comp. The VCO trimmers
are not precision, but cheesy ones. Every board uses different transistors. Trimmers are use in
some modules (the frequency shifter has like 8 of them), but I guess I'm not into the 'West Coast
Sound'. I think a 1V/Oct input with a 10-turn trim would be nice.....and knowing Don, he probably
did this *on purpose* to cause 'interaction' to 'find your own center of VCO happiness'. Whatever
:)

I would have use a switched pot, so that you had a choice of fixed or variable tracking. Guess
they were out that day when he went shopping :)

Paul S.
break time

--- In motm@yahoogroups.com, "Paul Schreiber" <synth1@a...> wrote:
> OK, I'm not a Buchla expert, but I can see an immediate reason it
was hard to do "Carlos music"
> on them.

Right!  Remember what he was trying to do AND for whom.  The East
coast experimental musicians had grown somewhat tired of their musique
concrete and oddball recordings-Varese' had done it all before!  On
the West coast, though, the was still a mood of "better living through
technology".  Subotnik and his followers were still getting audiences
with their compositions (though some of this was probably due to the
abundence of mind altering substances available at the time)and when
they requested the services of Don Buchla, Don initially thought they
were proposing a buisness venture!  

Both Buchla and Moog were supplying artists with the ability to create
sounds without the ordeal of splicing tape.  One control protocol
offered the ability to conform to music as it was expected, while the
other demanded experimentation and the abdication of control at times.

Given a choice, what should real synthesis be?  Given the above, would
Don have used a 741 or a TL071?  I wouldn't think twice about my answer...

Chub-out of control and proud of it!

Where I went to school in the '70's, we had Buchla and ARP synths, 
and I always found the contrast between those to be quite marked. 
The ARP was like a lab instrument for EE's: precise, logical, 
calibrated, does exactly what you tell it to, nothing more and 
nothing less. The Buchla was, in a word, funky. You didn't tell 
the Buchla what you wanted. You kinda put it in the general 
neighborhood of where you wanted to go sonically, and it went the 
rest of the way on its own. The Buchla was capable of a lot more 
surprises than the ARP.

I'd be real careful about trying to improve the Buchla with EE
fixes. I don't suppose lower noise op-amps would hurt anything,
but even trying to improve VCO drift might have damaged its karma.

-BobC

-----Original Message-----
From: osthelder [mailto:osthelder@...]

Both Buchla and Moog were supplying artists with the ability to create
sounds without the ordeal of splicing tape.  One control protocol
offered the ability to conform to music as it was expected, while the
other demanded experimentation and the abdication of control at times.

Chub-out of control and proud of it!

> I'd be real careful about trying to improve the Buchla with EE
> fixes. I don't suppose lower noise op-amps would hurt anything,
> but even trying to improve VCO drift might have damaged its karma.
>

What I stress is *understanding* where the "karma" comes from. I claim that 99.99% of 'musical
karma', especially when dealing with electronics, can be understood AND explained.

There is both intent and luck in Karma Engineering. An example of intent is the use of Vactrols
as control elements. In the MOTM-410, several solutions were available for the CV of the bandpass
filters, but a Vactrol was chosen on purpose. It just has a certain response that people like.

The Moog filter is 100% luck :)

The same is true on the Buchla: has anyone noticed there are no VCAs??!? That's because the ARE
no VCAs in a Buchla. There is a Quad Lowpass Gate module that is Vactrol based, that is used as a
VCA (or cheesy LPF). This prevents 'snappy' envelopes, so the sound is "mushed up" like an
Oberheim Xpander is (the Xpander has SW envelopes that are infamous for non-snappy-ness).

Also, PWM is non-existent. This is a shame, as I am a fan of PWM.

I agree 100% that some people enjoy the fact the Buchla is (being kind) "non-repeatable".
However, that's not my *personal idea* of what make a "great" modular (to me, it makes a great
pain-in-the-ass modular).

Paul S.

>
>The same is true on the Buchla: has anyone noticed there are no VCAs??!? 
>That's because the ARE
>no VCAs in a Buchla. There is a Quad Lowpass Gate module that is Vactrol 
>based, that is used as a
>VCA (or cheesy LPF). This prevents 'snappy' envelopes, so the sound is 
>"mushed up" like an
>Oberheim Xpander is (the Xpander has SW envelopes that are infamous for 
>non-snappy-ness).

There is a certain "sound" that comes from the Buchla Lowpass Gate that 
allows some very interesting percussive sounds.  I wouldn't call them 
mushy.  Subotnick got some very nice percussive tones out of the Buchla so 
I don't think that is quite it.  Yes, the Vactrols can be slow but there is 
a non-linearity there that makes it happen.  Perhaps it is a type of 
compression that occurs because of the Vactrols.  I certainly wouldn't 
compare it to the Xpander envelopes!


>Also, PWM is non-existent. This is a shame, as I am a fan of PWM.

Take another look at the wave control on those oscillators.  The complex 
oscillators have a variable "timbre" control that does some very different 
wave shaping.  For square waves, this is a bit of PWM.  It is quite a 
different sound that I haven't heard elsewhere (hint hint).

>I agree 100% that some people enjoy the fact the Buchla is (being kind) 
>"non-repeatable".
>However, that's not my *personal idea* of what make a "great" modular (to 
>me, it makes a great
>pain-in-the-ass modular).

It all depends on where you are going.   When I know exactly what I want to 
get, I go for MOTM and MOTM-like modulars.  When I want to explore and 
perhaps let the synth lead me to sonic places I haven't been before, I go 
for things like Buchla and Serge.  Of course, this isn't black and white 
and there are times when the opposite is true.

         Eric

> The same is true on the Buchla: has anyone noticed there
> are no VCAs??!? That's because the ARE no VCAs in a Buchla.
> There is a Quad Lowpass Gate module that is Vactrol based,
> that is used as a VCA (or cheesy LPF).

Cheezy?  Gotta disagree here!   I've got a Cynthia Quad LPG here and it's
anything but...

First, it makes a fine VCA - even for control signals (don't think the
Buchla did this) and the filtering is actually something special. Just can't
quite get the sound out of anything else that comes out of this. The
Vactrols really add a certain character and the slight "ringing" that you
get when you hit it with a very narrow pulse or trigger signal generates
some very interesting timbres, very useful for percussive textures.  I
believe that Cynthia also purposely used "unmatched" (you'll have to ask
her!) Vactrols so each gate would have a slightly different character.

Actually, I can't wait to get my hands on her Quad Band Pass!

I haven't heard the Buchla in comparison to the Cynthia module, but Cyn
based it on the Buchla 292, so it should be pretty close.

I'll take scope photos of the waveshaper as you turn the knob. It's a hybrid of a true fader
(like on the '310) with a sliding DC offset to "squish" the duty cycle *some* to get "PWM-like"
effects. It is unique in the industry. But JH's Interpolating Scanner can do that :)

Paul S.

Hi all-

That'd be interesting to see, both on the sine>square and the sine>saw.
Er, is the interpolating scanner going to show up as an MOTM ever, btw, or
should interested parties try to roll their own?

Frank

-----Original Message-----
From: Paul Schreiber [mailto:synth1@...]

I'll take scope photos of the waveshaper as you turn the knob. ...

> Er, is the interpolating scanner going to show up as an MOTM ever, btw, or
> should interested parties try to roll their own?

Yep, JH has submitted first-pass schematic :)

When? Nov-Dec.

Paul S.

I would agree with Paul that karma or mojo can be 99.99% explained.
To those purists who say replace all the parts with "original 
replacements" I would point out that the caps very likely have 
degraded over time and since many of the parts used were surplus the 
caps used may have already been significantly degraded by the time 
this particular unit was built.  I would replace everything with 
upgraded parts except in those cases where this changed the 
designers intent, for example if Don Buchla was relying on the 
terrible slew rate of a 741 for a particular effect then that part 
should be replaced by a 741 or similarly bad opamp.
I used to play on a Buchla quite regularly although it wasn't mine 
and it was a learning experience although I never would have bought 
one for the many reasons that have been previously mentioned.  I 
much preferred my minimoog although I eventually sold it as well.  
It sounded great but required tuning after every song.  It was one 
of the first.  The later ones were more stable but did not sound as 
good either.  
We have the best of both worlds with the MOTM which both sounds 
great and stays in tune. 
I used to rebuild synths many years ago and I would agree that no 
one in that business ever charges enough, in part because it always 
ends up taking you at least 3 times as long as you originally 
estimated and by the time you get a real handle on it you are 
committed.