Buchla 200e series, User Manual

Page: 76 / 78

Spectral transfers
By analyzing the spectrum of a sound applied to the “
odd” input, and applying
the spectrum to the signal from the “ even” input, we can perform a sort of
vocoding. To conserve several patchcords, choose “ odd > even” in the
“ SPEC-TRUM XSFER” section. The necessary connections will be
accomplished internally, the appropriate green LED will light, and the signal
emerging from the even output will have (approximately) the spectrum of the
odd signal input imposed on it. Note that the intermediate operation of
simultaneously illuminating both the “
odd > even” and the “ even > odd” LED’s
exchanges the spectra of the two inputs, potentially resulting in some
ridiculous sounds.
You’ll have to use some patchcords to map further correlations. Use the
envelope outputs to drive VCA inputs in whatever pattern you conceive.
If you’re fortunate enough to possess two 296e’s, you can perform a more
accurate spectral transfer, eliminating the inaccuracy introduced by the
odd/even business. The second 296e will analyze the sound applied to its
input, and apply the spectrum to an internal bus. To complete the operation
illuminate the “
ext > all” LED in the first unit.* The spectrum will now be
transferred to the signal applied to the input, resulting in a vocoded signal at
the “
all” output. For some even more non-predictable sounds try
simultaneously engaging the “ ext > all” mode on both 296e’s.
The math is tricky, but the controls work.
*Note: Connecting two 296e’s to each other requires use of a non-standard
“reversed” 3-pin cable inserted in the “296e UART LINK” header.
Sampling envelopes
Pressing the “
freeze” switch or applying a pulse will freeze the output
envelopes, but in different manners, depending on the setting of the “DISP”
LED’s. If either the “ A levels” or “ B levels” LED is illuminated, the envelopes
will be displayed for the duration of the freeze signal, and will become the new
A or B spectral response on its release. In other modes, the envelopes will
simply be frozen for the duration of the applied pulse or switch closure, but
they will not be stored.
All of the 296e’s data, with the exception of the gain and “
PRE-EMPHASIS”
control settings, may be stored as part of a preset. A preset manager (206e or
225e) is required for this trick.