CubuSynth VCFA – Manual PCB V1.2 Sept 2022
VCFA
Multimode VCF with LP,HP and BP outputs and
integrated VCA
Manual
PCB V1.2 Sept 2022
Written and Illustrated by Ruben Sponar
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CubuSynth VCFA – Manual PCB V1.2 Sept 2022
1. Introduction
The CubuSynth VCFA is a multimode VCF with LP,HP and BP modes with integrated VCA,
CV control over Frequency, Resonance and Volume. The CV input for the Frequency
features 1V/Oct scaling over about 2~3 octaves. So you can even create plucky melodies
with the resonance in "ringing" mode.
The Gain control can reach a nice, soft saturation.
2. Specifications
Size: 10HP / 50mm
Depth: 34mm (measured from the front panel)
Current Draw:
+12V: +14mA
-12V: -14mA
3. Key features
3 simultaneous Outputs for Low Pass, Band Pass and High Pass
Integrated VCA at the input stage
CV control over Volume, Frequency and Resonance
"Ringing" mode on upper Resonance setting
1 V/oct tracking over 2~3 octaves (with Freq CV attenuator on 100%)
Saturation on incoming signal (VCA stage) on upper Gain setting
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CubuSynth VCFA – Manual PCB V1.2 Sept 2022
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CubuSynth VCFA – Manual PCB V1.2 Sept 2022
Limited Warranty:
CubuSynth guarantees this product to be without defects in materials and workmanship for a period of one
year from the date of purchase (proof of purchase/invoice needed).
Malfunctions due to improper supply voltages, incorrect or reversed Eurorack power cable connection,
misuse of the product, removal of knobs, changing faceplates, or other causes determined by CubuSynth
are the user's responsability and are not covered by this warranty.
During the warranty period, all defective products will be repaired or replaced, in the CubuSynth
workshop with the customer paying the shipping costs to us.
CubuSynth takes no responsibility for any damage to persons or equipment caused by the operation of this
product.
Please contact [email protected] with any questions, authorization for return to manufacturer or any
needs and comments.
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CubuSynth VCFA – Manual PCB V1.2 Sept 2022
VCFA
PCB V1.2 Sept 2022
Written and Illustrated by Ruben Sponar
The CubuSynth VCFA was designed by Ruben Sponar, from first prototype in January 2021 to the finished module in
September 2022.
A few honorable mentions:
The main Filter circuit is based around the VCF-3 from Sculls&Circuits
The VCA part was originally designed by Tom Wiltshire (electric druid) and modified for the Input VCA stage and the
Resonance feedback path.
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