TipTop Audio Buchla Model 296t Programmable Spectral Processor Eurorack Module (52 HP)

Programmable Spectral Processor Model 296t

The Programmable Spectral Processor is an elaborate set of filters with a number of different outputs and special functions. Perhaps its most obvious function is that of a sixteen band graphic equalizer. The sixteen bands are labeled in hex numerals (0 through F) at the top and bottom of the module and the center frequency of each band is indicated above each slider attenuator.

Attenuator Outputs

• The signal input jacks, in the bottom right, offer the choice of putting a signal into the eight even numbered bands, all sixteen bands, or the eight odd bands.
• The Attenuator Outputs on the right of the module also offer Even, Odd, or All signal outputs. With a signal patched into the All signal input and taken out through the All attenuator output, the module functions just as a sixteen-band graphic equalizer. An attenuator at the very bottom will completely cut off any signal in that frequency band.
• The signal output jacks directly above each attenuator offer the signal present within that frequency band at 0 dB. These outputs are not affected by the attenuator's positions.
• The Comb Filter outputs offer signals from either all the Even or all the Odd bands and are also unaffected by the attenuators and are set at 0 dB.

Control Voltage Outputs

The control voltage outputs labeled Envelope Outputs are envelope follower outputs for each frequency band. In other words, the voltages from these outputs represent the amplitudes of the signals present within each band. The switch in the upper right selects Long, Combo, or Short envelope decay times. These outputs are not affected by the positions of the attenuators.

Programmed Outputs

The spectral processor can be voltage controlled in a variety of ways. The results of any control-voltage manipulation are presented to the programmed outputs. It is possible to sweep through the various frequency bands (much like a bandpass filter can sweep the frequency spectrum) using the left knob on the program control section.

Spectral Bias

• The pair of knobs and switches labeled Programmed Spectrum Transfer have a function often associated with a Vocoder circuit. The left switch, when up, patches each Even envelope follower output into its neighboring Odd control voltage input. In effect this causes the spectral processor to analyze the signal present at the Even input and duplicate its frequency spectrum in the Odd bands. If the signal presented to the Odd input has a broad enough frequency spectrum itself, the Odd programmed outputs will match timbres with the Even signal. The right switch performs the same function going from Odd to Even.
• If a microphone signal is the signal being analyzed, a harmonically rich signal from an oscillator can be made to duplicate vowel sounds in speech (this is known as a Vocoder patch). For this to work best, the input signal requires special equalization, this is the purpose of the two knobs next to the switches. When turned to the right, they boost the treble range of the Even and Odd input signals respectively. Since they affect both the attenuator and programmed outputs, they should be turned down (to the left) unless setting up a vocoder patch

LEDs

The LEDs are driven from the Envelope Followers and help to indicate when a 10 V p-p signal (such as one from the 258t) hit right on the frequency of a specific band, pushing its envelope follower up to it's maximum CV value of 10V. When using a vocoder patch the output signal gain might be low, setting the VCO right at a center of a band using the LED helps maximize the gain output. These lights do not indicate distortion or overdrive.

Eurorack Ready

• 52 HP Eurorack format module
• Maximum depth: 2" (52mm)
• Includes power ribbon cable with Eurorack power headers
• Power consumption: +12V: 360mA, -12V: 350mA

TipTop Audio MODEL 296t Specs

Sound Generation	Analog
Audio I/O	3x 1/8" / 3.5 mm Unbalanced Mono Modular/Eurorack Input 16x 1/8" / 3.5 mm Unbalanced Mono Modular/Eurorack Output 8x 1/8" / 3.5 mm Unbalanced Mono Modular/Eurorack Output
MIDI I/O	No
CV/Gate I/O	16x 1/8" / 3.5 mm CV Output 18x 1/8" / 3.5 mm TS CV Input
Patch Points	40x 1/8" / 3.5 mm Output 21x 1/8" / 3.5 mm TS Input
Eurorack Current Consumption	360 mA on +12 V Rail 350 mA on -12 V Rail
Horizontal Pitch	52 HP

Item Type	Eurorack Module
Sound Generation	Analog
Expression Controls	5x Knob
Number of Pads	No
Built-In Effects	Yes
Built-In Speaker	No

Oscillators	No
Mixer	No
Amplifiers	No
Envelopes	No
Filters	No
LFOs	No

Sequencer	No
Arpeggiator	No

Audio I/O	3x 1/8" / 3.5 mm Unbalanced Mono Modular/Eurorack Input 16x 1/8" / 3.5 mm Unbalanced Mono Modular/Eurorack Output 8x 1/8" / 3.5 mm Unbalanced Mono Modular/Eurorack Output
MIDI I/O	No
CV/Gate I/O	16x 1/8" / 3.5 mm CV Output 18x 1/8" / 3.5 mm TS CV Input
Patch Points	40x 1/8" / 3.5 mm Output 21x 1/8" / 3.5 mm TS Input
Sync I/O	No

Power Requirements	Eurorack Power
Eurorack Current Consumption	360 mA on +12 V Rail 350 mA on -12 V Rail

Horizontal Pitch	52 HP
Included Accessories	No

Package Weight	2.34 lb
Box Dimensions (LxWxH)	11.1 x 6.3 x 3"