Buchla - 257e Control Voltage Processor

The 257e is an eightfold CV-Processor. It contains transfer function from the 256e twice as well as six slew processors. Two of the slew processors share a parameter set, but have independent inputs and outputs. If you think of other known slew processor circuits because oft he parameters being named „positive slew“, „negative slew“ and „auto-pulse“, you should be careful. E.g. „auto-pulse“ is not an "LFO" mode, but generates pulse signals as soon as the direction of the incoming control voltage changes. The task of the 257e is to process CV -ignals and generate pulse signals. In combination with 281e you have a big adventure playground...

The upper two CV processors correspond to the transfer functions of the 256e. Here you can scale, move and invert CVs. As with the 256e, an additional breakpoint in the function can make them more complex.

Below are six Slew processors, each sharing a parameter set in pairs, but with independent inputs and outputs. Each CV processor has a CV input as well as a pulse and CV output. Falling control voltages can be processed with the voltage controllable parameter "Neg Slew" in their fall time. Increasing control voltages are processed with voltage controllable parameter "Pos Slew" in their rise time.

The curve characteristics of "Time" and "Rate" can be selected via switches. While "Rate" leads to more dynamic control voltages with faster input signals, "Time" works linearly and can enable smoother slews.

If the "auto-pulse" function is activated, a trigger is generated at the pulse output as soon as the CV of the output changes its direction. Since the changes at the output are relevant, the slew parameters also influence the generation and distribution of the pulse signals.

While other slew processor circuits are known to work as envelopes or LFOs, this is not the case here or only to a limited extent. Of course the 257e can be used to process any CV signal, but within the 200e system the 281e module is a particularly strong partner.

All settings of the module can be saved and recalled with the preset manager of the modules 206e and 225e.

Please note: Buchla 200e products may have lengthy waiting times, as they are manufactured in small quantities only.