Welcome to the Buchla & Tiptop Audio 200 series project. In this project Buchla has teamed up with Tiptop Audio to resume the production of Don Buchla’s 200 series and convert it to Eurorack standards. These extremely rare pieces of equipment made almost half a century ago will once again be available, and this time to a wide audience.

Model 257 Dual Control Voltage Processor consists of two identical sections, each of which permits several applied control voltages to define a single output voltage according to the equation:

(Va * K) + ((Vb * (1-M)) + (Vc * M)) + Voset = V_out

The algebraic manipulations possible with this module include addition, subtraction, scaling, inversion, and multiplication. Also incorporated is the capability of using one control voltage (M) to transfer control from one applied voltage (V_b) to another (V_c).