GMS-301MU VC Oscillator

Low cost precision oscillator

The GMS-301 Voltage Controlled Oscillator uses a precision, temperature compensated  triangle core oscillator with 1V/Octave, linear FM, and exponential FM control inputs. The base frequency is set using a ten octave course control and a +/- 1/2 octave fine control. In addition to the triangle wave output, the oscillator outputs sine, saw, and rectangular pulse wave. Output levels for all waveforms are 10 Volts peak to peak. 

A panel switch selects the basic frequency range of 1 Hz to 20 kHz or the LFO range of 0.01 Hz to 400 Hz. The linear FM input has an attenuator input and an AC/DC coupling switch to simplify removing DC offset from modulating signals.

The exponential FM input also features an attenuator. The rectangular pulse waveform can be pulse wdth modulated using the PWM IN connector and the level of modulation can be controlled with a attenuator. An LED on the front panel is connected to the oscillator output to indicate waveform activity. It is also useful for setting up the LFO frequency.

Technical Specifications

Course Frequency Range
10 Octaves beginning at 16Hz

Fine Frequency Range
+ or - 1/2 Octave

LFO Frequency Range
0.015 Hz to 400 Hz

Waveform Voltage Range
10 Volts Peak-to-Peak

Frequency Control Voltage Standard
Exponential 1 Volt per Octave

Typical Input Impedance
100K Ohms

Typical Output Impedance
1K Ohms (short circuit protection)

Module Power
+15 Volts 35 mA., -15 Volts 35 mA.

Module Size
Panel height - 8.75 inches (222 mm);
Panel width - 2.125 inches (54 mm);
Depth (behind panel) 2.1 inches (53 mm)



We produce electronic synthesizer modules in the two most popular formats, MU (Moog compatible 5U) and EU (Eurorack compatible 3U). A wide range of voltage controlled modules including oscillators, amplifiers, mixers, envelope generators, special effects units, wave generators, filters, power systems and cases allow users complete freedom to configure any desired electronic music instrument.


Grove Audio builds microphones, preamplifiers, equalizers, compressors and other professional audio equipment for performance and studio use. We build units in popular formats such as 19 inch rack mount and 500 series 3U modules. We can also produce custom designs on request. Contact us for a consultation.


You can explore all of our products, download spec sheets, and purchase our products in the Grove Audio Synth Store. You can also learn about our periodic specials and new product introductions. Click the button below to go directly to the store.

Follow Us!

Grove Audio Help
  • Email:
  • Phone: 608 886-6503


Grove Audio has been manufacturing professional recording and modularized electronics for musicians and performers since 1995.