The Discrete Core Ladder VCF shines with crisp sound, a very low noise-floor and a multitude of technical gimmicks. The module features a three-channel input mixer with saturation capabilities. Four outputs provide audio material filtered with -6 dB, -12 dB, -18 dB and -24 dB edge steepness. Each connector is phase-shifted by 90 degrees compared to the prior socket. Cutoff and resonance are voltage controllable. While self-oscillating, the filter can be played chromatically. This means, that the Discrete Core Ladder VCF is usable as a quadrature VCO as well. Thanks to a boost knob, the bass fundament can be kept intact at high resonance settings. A high-pass filter in the feedback path allows users to alter the resonance behaviour. Compared to Moog's classic Ladder design, the sound of the ACL circuit is considerably rougher. Saturation effects lead to roaring results. Tip: Be sure to try out filter FM patches!
Sometimes an envelope generator doesn't have to be function-ladden, but just reliable, solid and good. This is what ACL achieves with the Envelope X3 module. The technical quality originates in precision components, as used in measuring instruments for instance, in order to keep the parameters exact, always the same and to keep you happy.
Three identical, classic Attack-Decay-Sustain-Release envelopes are integrated; function-wise rather simple with a gate input and one positive and one inverted envelope output each. The gate inputs are normalized (1 -> 2 -and 1 -> 3; with input 1 as master) which minimizes the amount of patch cords. Normalizations can be disrupted by patching a cable.
Each envelope generator has a time range switch with two positions to select between short and long envelope times.
The LEDs for visualisation were omitted to keep the power consumption low.
The VCO is capable of delivering that without sacrificing tracking precision and low temperature drift.
Available waveshapes are saw, inverted saw, triangle, sine and PW rectangle, which uses the saw wave from the waveshaper as a carrier for the PWM. It can be varied by CV and manually within a range from 0 percent to almost 100 percent.
The possibility to play VCO in low, middle and high modes, together with the 10 turn precision Tune pot results in a very convenient "on the fly" way of tuning the module. Its core can be frequency modulated exponentially from two inputs, both CV controlled. When fully open the input attenuators are calibrated for 1 V/Oct. There is one more input - for linear modulation with manual amount control, AC coupled and configured like differentiator. In this way it is sure no detuning caused by DC, will take place when modulation signal is presented at the FM Input, but only frequency modulation, centred around the already played tone.
Syncing the core to outside source makes a whole lot of difference, when there is the additional option to vary continuously by CV and manually the threshold of synchronization from no sync, soft sync and hard sync. This input is configured as attenuverter for even more flexibility. Note when the Threshold pot is fully CW there will be no sound output anymore. The reference wave source for the soft sync is the saw from the oscillator. Sync input itself reacts to every repeatable waveform with amplitude higher than 1.2 Vpp.
The module has two exponential response VCAs with voltage and manually controlled gains, input level attenuators and overload indicators.
When no jack is connected to IN 2 and CV 2 inputs, they are normalized to IN 1 and CV 1 inputs respectively. Some of the possible configurations with this arrangement allow the gain of both channels to be controlled together with one CV, while processing different audio signals, or both channels to be operated individually, if needed. The gain balance between both VCAs and hence the panorama position of a stereo signal is manually and voltage controllable. The common gain of the two channels is also manually adjustable with a single pot.