Oakley VC LFO

MOTM format, 1U

kits are available in the v2 issue pcb, and the v3 issue pcb

From Oakley: "This is a versatile yet easy to use voltage controlled low frequency oscillator module that can also be used as an audio VCO over a useful range.

The unit features sinusoid, sawtooth, ramp, triangle and square outputs. All are available simultaneously. A sync input is available to reset the waveforms to a fixed point.

The module features two CV inputs. One is fixed at 1V/octave. The other CV input is controlled by a single pot on the front panel. When the pot is turned right of its central position, the pot acts as a normal attenuator; increasing the sensitivity of the CV input to a maximum of 0.5V/octave. Left of centre, the pot will act in inverting mode. Fully anti-clockwise the input will respond to -0.5V/octave.

A tricolour LED indicates the output status.

For DIY builders of this module it is possible to purchase the Sock8 circuit board which is available separately. This little board speeds up the wiring of the eight 1/4" sockets and reduces the chances of any wiring errors.

Power (+/-15V) is provided to the board either by our standard Oakley 4-way header or Synthesizers.com header. Current consumption is approximately 40mA per rail.

The board size is 104 mm (high) x 104mm (deep).

Specifications

The VC-LFO has an operating range of lower than 0.002Hz (one cycle every eight minutes) to over 14kHz from the front panel controls. The range can be extended with external CV inputs. The maximum frequency of the VC-LFO is well over 25kHz.

Range of Frequency control: 17 octaves

eg. When the fine control is central the frequency pot can vary the output from 0.016Hz (one cycle per minute) to 1.7kHz.

Range of Fine Frequency control: 6 octaves

eg. When the main frequency pot is central, the fine control will vary the rate from 1Hz to 64Hz.

These frequencies can be altered over a limited range by the onboard trimmer, or more significantly by a change in the master timing capacitor.

When used as an audio rate VCO the usable range that conforms to 1V/octave (to +/-2cents) is over six octaves from approximately 32Hz to 2kHz. This is none too shabby for a low frequency oscillator. For accurate musical use over 2kHz we recommend that you use the Oakley VCO.

Sync input requires a fast rising gate exceeding 4V when active, or at least 2V peak pulse or sawtooth waveform.

more information here: oakley vc lfo