The Buchla 257e Control Voltage Processor Module, everything you need for manipulating, rearranging and modifying your CV signals in various ways. 257e is comprised of two parts that offer a variety of possible options for diversifying your CV signals and making them something completely new.

The top section is reminiscent of the 256e….well in fact it’s a actually two channels of said module. For those who are not familiar with the function, allow me to explain.

The top portion of the module provides control over incoming voltage selection, multiplication, addition, scaling, inversion and non-linear transformation of the voltages. You can easily apply simple mathematical changes to incoming control voltages that turn them from simple simplistic, like a slow moving envelope function into a more complex results.

The 257e provides cross fading applications for two CV’s, which are connected at input 1 and  input 2, the input selection between input 1 and input 2 can be manually controlled using the “in select” pot, or you can apply a voltage to sweep between the two incoming voltages. From there you can manipulate the CV using the “output @ 0Volt in” and the “output @10v in” pots, to create inversions (and much more) and by activating the breakpoint control, you can apply logic based changes to voltages.

The algorithms that are created on the module are represented on a dot matrix display, which give you a good estimation of the resulting function that’ll be produced by the module, bear in mind this is a simplistic display, but the resulting voltages are incredibly precise.

The bottom half of the 257e provides three channels of slew and portamento, each with two CV inputs. The Slew rates can be controlled from the slew CV input, where voltage can be applied to modify the slew rates or glide from one state to another.

There’s four channel of CV controllable slew, each with two CV outputs for the resulting voltages and a dual pulse outputs, which can be used to trigger other events in your system.

257e is one of those tools you don’t think you need until you actually do. The ability to drastically modify CV in various ways, quickly and more importantly with positive results shouldn’t be overlooked.

The main features of the Buchla 257e Control Voltage Processor includes

Dual mode CV manipulation tool

Provides two channels of transfer controls (ala 256e)

Three channels of voltage controlled slew

200E preset storage compatible