200e

hi

> As far as I understood it, the main conceptual difference between the
> 259e and the 261e is that the 259e's sound generation path is all
> digital (modulator osc, principal osc and waveshaper are digital),
> whereas in the 261e has a hybrid sound generation path with the
> modulator and principal oscillator still being digital and the
> waveshaper being analog. Please correct me if I am wrong.

you're right

> I tried out the 261e at NAMM–I know, this is most certainly not the
> best environment to do the qualities of any instrument justice–

right again

and
> noticed that when FM'ing the modulator with the principal, and
> gradually increasing the modulator pitch to its top registers, the FM
> result at the principal output turned into some sort of digital noise
> in the upper registers of the modulator. I guess this is a result that
> is to be expected given the digital nature of both modulator and
> principal being digital, right?

not really. i am sure you were using the audio output jack of the
modulator osc and the FM input jack of the principal osc. this,
unfortunately, produces massive jitter due to the low sampling rate of
the FM input. i don't like it either.

however, the more logical approach to using the mod osc for FM is to
use the internal pitch modulation routing. in this case the modulation
is performed directly in the computer, rather than sending to a DAC,
amplifying, resamplng, and scaling. with internal modulation the new
frequencies are computed on the same processing cycle as the oscs, no
jitter whatsoever. so the digital nature of the sine generation is not
the problem per se; the problem is as usual the interface between the
two domains.

> Reading Thomas' original post made me recall this NAMM experience.
> Now, if both modulator and principal oscillators were analog, I guess
> (a) the FM result were different (no digital noise), and
> (b) the ranges of the fundamentals of the oscillators were not limited
> to 7040 Hz. (Assuming that the resolution of the 200e's storage system
> can be scaled to accomodate a wider oscillator frequency range).

that would be a radically different instrument. don's logic when he
designed the 200e was that there are plenty of pure-analog oscillators
available in the world already; he very much wanted the perfect recall
capabilities of the new system with the ability to interface with the
CV world. if you want a 258 clone or a 259 kit or a zeroscillator,
they are obtainable.

> If I now take at Cuari7's comments about the quantizing errors at the
> waveform generator's frequency control inputs into account, which led
> to him buying 259 (not 259e) waveform generators, it looks to me that
> there might be a need in the 200e community for yet another Buchla
> waveform generator, one with not only the waveshaper being analog, but
> also the principal and modulator oscillator being analog.


see above