Z2040 VC-Filter + Z2040 LP-VCF GAIN VC-GAIN VC-RES IN 0db MIN CLIP MIN MAX RESONANCE FREQUENCY OUT CUT 24db FM PASS FM VC-FM + MIN MAX MIN MAX VC-FM Tipt p A u d i o
Z2040-VC-Filter Design - Gur Milstein Special Thanks Shawn Cleary Sean Coulter Matthew Davidson Michael McGrath Yigal Mesika Mark Pulver Rene Schmitz Andreas Schneider Bobby Voso MADE IN THE USA Tiptop Audio 2009 All Rights Reserved
Welcome. This quick start guide provides an introduction to the operation of the Z2040 VC-Filter. The Z2040 4-Pole VCF is an enhanced version of the famous SSM2040 filter chip. Both the Z2040 and the SSM2040 are based on a discrete circuit design covered by a US patent assigned to Oberheim Electronics in the 70’s. Although the Z2040 is inspired by this design, the Z2040 is not designed to be an exact reproduction of the SSM2040 sound. The Z2040 significantly extends the capabilities of this vintage sound.
HD2 2 1 RESONANCE VC-RESONANCE HD3 VC-GAIN IN 24db LP filter VCA OUT 1 2 3 HD1 FREQUENCY GAIN VC-FREQ VCA VC-FM VC-FM FM FREQUENCY Fig. A HD2 RESONANCE VC-RESONANCE HD3 VC-GAIN GAIN 24db LP filter IN VCA OUT 2 1 1 2 3 HD1 FREQUENCY VC-FREQ VCA VC-FM VC-FM FM FREQUENCY Fig. B (cont. on pg.
Please Note: When the VCA is configured to filter output it will block the sound, only by applying a CV to the VC-Gain input will it open the VCA for sound to pass through. The front panel Gain knob functions totally independent of the VCA and only sets the input Gain regardless of the VCA position (VCA on Input or output). When the VCA is configured to the Input then the audio from the VCA and from the Gain Knob are mixed together.
0db: In this spot the unique resonance-gain-compensation circuit will kick in, providing a gain compensation of the input signal as the Resonance is increased. This gain compensation loop dramatically reduces the drop in volume of the input signal when the Resonance is increased, in turn, producing resonating sounds with additional “punch.” Just past 0db - MAX: This range causes the Z2040 to behave in a non-linear fashion which can result in some very interesting sonic results.
Understanding the VC-FM: Most VC-filters have a CV input to sweep/modulate the cut-off frequency, in the Z2040’s case this input is labeled FM (Frequency Modulation). The Z2040 adds a unique feature providing the ability to modulate the magnitude of the FM signal by another signal, this is done by placing a VCA on the FM line. This simple yet effective structure provides a variety of modulation tricks.
Self Oscillating: The Z2040 can be used as a pure Sine wave Voltage Controlled Oscillator. With no signal on the input and the Resonance knob at maximum the Z2040 will oscillate a very low distortion sine wave. Although the Z2040 does not provide an exponential 1V/Oct input, the Z2040 will track precisely over about 7 Octaves using MOTU Volta calibration. Modulating the VC-Resonance and/or the FM inputs in self oscillation will transform the sine wave and add harmonics.
VC-FM / VC-FM IN The VC-FM knob attenuates the VC-FM IN Input impedance: 22K Ohm Input Range: +/-2.5V* Gain / VC-Gain Gain knob sets the input gain to the filter regardless of the VCA position. Input impedance: 30K Ohm Input Range: +5V* * Input range is not limited and can exceed these values Impedance: Audio In: 35K typical, 10K at maximum gain Audio out: 220 Ohm Power : +/-12V +/-15V * * Powering the Z2040 from +/-15V is supported, some slight variation in control range may occur.
Enjoy, make music.
