Constructional difficulty: Easy to moderate. Some simple setting up required.
The suggested layout of the VC-LFO module in a 1U wide panel.
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 limited range.
The unit features sinusoid, sawtooth, ramp, triangle and square outputs. All are available simultaneously. A sync input will reset the waveforms to a fixed point when the input voltage exceeds 2V.
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 bicolour LED indicates the output status. An optional range switch determines whether the unit is to be run in audio or very low frequency mode. A large degree of overlap is available for really wide sweeps.
The new PCB is 4.1" x 4.1" in size.
Specifications
The VC-LFO has an operating range of 0.002Hz to 11kHz via the CV inputs.
Using the front panel frequency pot alone the following frequencies are obtainable:
Hi Range: 0.016Hz (cycle time of 1 minute) to 2kHz.
Lo range: 0.002Hz (cycle time of 8 minutes) to 150Hz.
These frequencies can be altered over a limited range by the onboard trimmer, or more significantly by a change in the master timing capacitor.
As an audio VCO the usable range that conforms to 1V/octave (to +/-3cents) is over four octaves from approximately 32Hz to 750Hz. For accurate musical use over this frequency we recommend that you use the Oakley VCO.
Project Downloads
Use 'save as...' button to download and view the file. IE users need to right hand mouse click and then choose 'save as'. Links to schematics are available to purchasers of the PCB or module and will be sent via e-mail when the board(s) are shipped.
Front Panel database
A Schaeffer front panel can be made for a MOTM compatible 1U wide VC-LFO. The database for the module can be found be clicking here.
To read these files you will need a copy of 'Frontplatten designer' from Schaeffer. The program also features on-line ordering, so its now even easier to buy your panels from Scheaffer.
The company are based in Berlin in Germany and will send out panels to anywhere in the world. Delivery to the UK normally takes around ten days. For North American users you can also order your Schaeffer panels from Front Panel Express.
Prices
VC-LFO issue 1 PCB
........................................ 18UKP
VC-LFO pot kit
.................................................... 6UKP
VC-LFO pot bracket kit
...................................... 2UKP
The VC-LFO pot kit contains two high quality Spectrol 148 pots only. The pot bracket kit contains two Oakley Spectrol pot brackets and two extra nuts to mount the Spectrol pots to the board. No knobs are provided.
All other parts can be purchased from you usual electronic component supplier.
See the prices page for ordering information, shipping charges and payment methods.
All prices include VAT at UK rates. Shipping/postage is additional to these prices. See also the FAQ page.
Back to projects page