Audiophile Circuits League Discrete Core Ladder VCF is a beautifully
liquid sounding Moog-inspired transistor ladder design filter, with four
outputs (6dB, 12dB, 18db, and 24db). We believe ours sounds fantastic,
but there are many great sounding filter modules available, so we wanted
to do something new, and designed a filter that addresses traditional
limitations and offers new possibilities.
Our VCF features a 'BOOST' control. In most ladder VCF designs, the
lower frequencies get attenuated (i.e the bass is lost), when you dial
up the resonance. BOOST restores the low frequencies, boosting them at
high resonance settings, allowing you to play extreme squealing
basslines that are still... basslines.
Furthermore, our Discrete Core Ladder VCF features four separate
buffered outputs for 6dB, 12dB, 18dB, and 24dB/octave sloped filters.
This offers many many advantages over a simple switch selecting one
slope setting or another.
Each of the outputs taps consecutively into the signal path as it is
progressively filtered, and all of them can be routed and used
separately... and simultaneously. Things get interesting then, because
each stage is phase shifted by 90° from the previous. This offers very
creative possibilities for combining these signals, as when you combine
phase-shifted signals, some frequencies are cancelled. When combining
them using a mixer that allows you to invert the waveforms of some of
these, you can create fascinating bandpass filters, and everything in
between low- and high-pass filters. It is similar to Oberheim's Expander
Filter, but with its own unique character, since our filter is modeled
on a Moog design.
We have not limited ourselves to features, of course: Signal path is key
to making a filter sound fantastic. A fully discrete, low noise, low
distortion audio path is used throughout the circuitry. And we designed
it to saturate at exactly the point our experience has taught us
responds best, and works well with other modules. When approaching 8V PP
(Peak-to-Peak), the filter will create an awesome creamy and compressed
sound that bends and evolves ever more as you push the input signal
harder. And yet at lower signal levels, low distortion discrete buffers
ensure the overall distortion of the signal is quite low, enabling a
very clean sine wave when the filter is self-oscillating a little.
The end result offers the lush characteristics of a Moog filter, but
with creative and practical possibilities unique to our VCF.
