Discrete VCF

A multimode filter made with discrete transistors

The Stoel Music Systems Discrete VCF is a vintage-inspired voltage-controlled filter that uses several matched transistor pairs arranged in two sequential filter blocks. It sounds completely different from the famous east coast “Ladder” filter design. There are no integrated circuits or op-amps in this design. It has a gentle slope of 12dB per octave and features low pass and bandpass modes for added versatility.

There are two CV inputs for modulating the filter frequency. CV input 1 is full-scale for keyboard tracking purposes, and the amount of CV input 2 is adjustable with a knob. The resonance will self-oscillate except at very low frequencies. This filter is excellent for leads, basses, and percussion sounds.

All Stoel Music Systems modules feature aluminum front panels with a durable high-gloss white finish. For a crisp appearance and exceptional durability, the front panel markings are digitally printed at high-resolution with UV-cured ink. Mounting holes are plated to significantly reduce screw rash. The power connection features polarity protection to prevent accidental damage to the module if it is connected backward.

Each module includes a 12” long 10-pin to 16-pin ribbon cable compatible with the Eurorack standard, M3 mounting screws, and a complimentary sticker.

Mode EM1201

https://www.stoelmusicsystems.com/eurorack/discrete-vcf