Notes: CEMosc is here, a stable AS3340 based VCO which tracks beautifully, and is feature rich. Easy to build and calibrate too.
- Onboard voltage regulation for tuning and tracking stability
- A rotary octave switch as well as a fine tune knob
- Both manual PW as well as PWM are available
- Linear and Exponential FM inputs, each with attenuators
- Both soft and hard sync
- Sawtooth, Triangle and Pulse outputs
Notes: CEMvelope is based on the legendary ADSR section of the Sequential Circuits Pro-One monosynth, with minor adaptations to integrate it into Euro format. Smooth and snappy! It has a gate input as well as a trigger input, the trigger input works in conjunction with the gate input for multiple triggering from a suitable controller device.
Eurorack variable filter synth module based on Roland System 700 filter module - 10HP wide
Notes: Based on the Roland System 700 state variable filter module. Lowpass, bandpass and highpass outputs.
A big part of the sound of the State 700 is the way in which resonance is reduced as the audio inputs are driven harder. It won't self oscillate with a hot audio input, throttle back a little and you'll get squelchy ear bleeding resonances!
For audio demos, please visit - https://soundcloud.com/frequency-central
Eurorack filter synth module based on Roland System 100M VCF - 10HP wide
Notes: Frequency Central "System X Filter"
Frequency Central proudly announce the release of the 'System X Filter'. It's a clone of the Roland System 100M VCF, and uses 2 x LM13700. There's an additional 12dB/oct output which is 180 degrees out of phase with the 24dB/oct output. Mixing the two outputs will give bandpass.
First up, classic 24dB/oct LPF. The two VCOs are my Hearn Morley HMVCO1c, there is a little -1oct subosc added as FM of the VCF towards the end of the clip:
Eurorack multi-waveform syncable Low Frequency Oscillator (LFO) module based on Electric Druid TAPLFO2D family of code - 4HP wide
Notes: Wave Runner LFO:
Wave Runner is a multi-waveform sync-able LFO based on the Electric Druid TAPLFO2D family of code, but with some significant additions and improvements. The TAPLFO2D-FC PIC and code is exclusive to Frequency Central and was developed specifically for the Wave Runner, and is not compatible with similar modules.
- sample and hold
- stepped triangle/sawtooth/ramp
All waveforms can be skewed using the Distort knob, as well as control over pulse width of square, and distortion of the cyclic waveforms, this get you control over Noise freq as well as bitcrushing, bitcrush of S/H down to 1 bit for random triggers.
Tap sync input, for syncing to whatever. Wave Runner measures the last two incoming pulses and syncs itself to these. Multiply knob allows for Wave Runner to run at x0.5, x1, x1.5, x2, x3 and x4 of the incoming sync pulse. Freq is from stupid slow (0.025Hz) into low audio range (50Hz).
The latest version also features Level CV input to control the absolute output level of the LFO.
B-STOCK: Box opened, product in perfect working order
Notes: ***B-STOCK: Box opened, product in perfect working order***
The Frequency Central Wave Runner LFO is a 5U format low frequency oscillator with 8 waveforms and a range of sync and skewing options.
Wave Runner includes 8 waveforms that include saw, ramp, pulse, triangle, sine, noise, sample and hold and a selection of stepped options, for less blase modulation results. The modules frequency range is ridiculously wide range, going from 0.025Hz all the way into 50Hz audio range.
The module also includes an onboard distortion circuit which lets you bend and mangle the waveform to create less linear and more unpredictable modulations and sounds. This distortion section lets you effectively crush the waveforms and create new voltages.
Notes: Frequency Central's Whiteface is a new voltage controlled analogue filter for Eurorack based on the ARP 4023 filter, found in the "whiteface" Odyssey MK1 Synthesiser.
Besides the classic cut-off & resonance controls, it comes with two audio inputs as well as two CV inputs.
The rare parts have been engineered out (and the need for matched transistors for the CV input section) by using a Roland style circuit there instead - no change to the vibe though! The audio path remains pure ARP, with one exception. Built stock from the schematic, the resonance would clip above 3 o'clock, in a way which is neither musical or desirable. An inverting buffer has now been used, which adds a bit of gain to bring it up to modular levels. A nice side effect of the inverting buffer is that if you mix the input signal with the filter output, and find the sweet spot, you can do high-pass filtering too!