TagLine Here

DD1 - Modulator / Low Pass Gate


Sold Out
  • 0 Units in Stock
  • Shipping Weight: 0.1kgs

The DD1 is a dual module providing a Modulator (BalMod) and a Low Pass Gate (LPG) in a compact form. The new Rev.2 version has added a mode switch to the modulator section.

The Modulator section is built around the AD633 Precision Multiplier chip. The main application is Ring Modulation (RM) where two input signals are combined to generate the sum and difference frequencies. The RM is DC coupled and can also be thought of as a VCA but with the ability to invert the signal under voltage control. For example, feed a VCO signal into one side and then a DC control into the other input - raising the DC control from 0V upwards will give typical VCA response while taking the DC control below 0V will give a VCA response but with the polarity inverted.

The AM mode can be thought of as a little bonus - it does not behave as a true VCA, but gives a very different sound to the RM mode.

The Low Pass Gate was created by Don Buchla and imparts great effects on audio signals as a combined VC Filter / Amplifier. The key to the LPG is the Vactrol - a variable resistive element, driven by an LED, which changes the intensity of the audio processing. It is the slightly slow response of the Vactrol that gives the audio effects such a natural feel and is the wonderful strength of the module. The LPG can be run in three different modes - VCF, VCA or a middle mode that combines the two.

Input / Output: Modulator - DC coupled typical input ranges. LPG - AC coupled Signal input, DC coupled Mod input
Width: 1 FW
Current: +ve 15mA / -ve 25mA
User Adjustments: None

Added on Wednesday 31 December, 2008.