24Db VOLTAGE CONTROLLED DUAL MODE FILTER
MODULE 9004

FEATURES:

  • THE PHATRON LADDER FILTER
  • RESONANCE FUNCTION EXHIBITS A DISTINCTIVE MINIMOOG-LIKE BRILLIANCE
  • UNIQUE DESIGN RESULTS IN NO LOSS OF GAIN AS RESONANCE IS INCREASED
  • UTILIZES A COPPER SHIELDED, C.M.S. SUB-MODULE FOR LOW NOISE OPERATION
  • LOW D.C. OFFSET AND CONTROL VOLTAGE FEEDTHROUGH FOR "THUMP FREE" OPERATION
  • BI-MODE DESIGN ENABLES SIMULTANEOUS LOWPASS, HIGHPASS
  • COUPLER FUNCTION LINKS 2 MODULES FOR 24Db BANDPASS AND NOTCH (PHASING)
  • 4 ATTENUATED FM INPUTS
  • 4 INPUT AUDIO MIXER
  • ACCURATE EXPONENTIAL FREQUENCY SCALE

CONSTRUCTION:

  • ERGONOMIC, FLOWCHART STYLE GRAPHICS
  • LARGE COMMUNICATION KNOB FOR MAIN CUTOFF FREQUENCY
  • HIGH QUALITY ELECTRONIC COMPONENTS, HAND ASSEMBLED AND TESTED
  • MILITARY GRADE HARDWARE, POTENTIOMETERS, JACKS, KNOBS
  • HI RESOLUTION, BRUSHED, BLACK ANODIZED FRONT PANEL
  • HAND SELECTED, LOW NOISE. LARGE GEOMETRY TRANSISTORS
  • SUB-MODULAR DESIGN PROVIDES EASY SERVICE, UPGRADES

C.M.S. MODULE 9004 IS A HIGH PERFORMANCE VOLTAGE CONTROLLED FOUR-POLE DUAL MODE FILTER DESIGNED FOR SUBTRACTIVE SYNTHESIS AND HARMONIC ENHANCEMENT IN THE C.M.S. MODULAR SYSTEM. EXTENSIVE C.M.S. RESEARCH WITH VINTAGE SPECIMENS AND YEARS OF EXPERIMENTATION WITH COUNTLESS VARIATIONS ON THE MOOG TRANSISTOR LADDER HAVE RESULTED IN A FILTER EXHIBITING A REMARKABLE VINTAGE SOUND. 24Db HIGHPASS WITH RESONANCE AND 24Db LOWPASS WITH RESONANCE ARE SIMULTANEOUSLY AVAILABLE. AN INNOVATIVE DESIGN ENABLES RESONANCE TO BE ENGAGED WITHOUT SACRIFICING LOW END OR VOLUME, A FIRST FOR THIS TYPE OF FILTER ARCHITECTURE. ALSO THIS IS THE FIRST FILTER MADE THAT EXTRACTS A HIGHPASS RESPONSE FROM A MOOG STYLE TRANSISTOR LADDER, PRODUCING A VERY COLORFUL, BRILLIANT RESONANCE.

REMARKABLE RESONANT TEXTURES CAN BE REALIZED WHEN A 9004 IS COUPLED WITH A 9005 TO ENABLE 24Db BANDPASS AND 24Db NOTCH RESPONSES WITH SEPARATE RESONANCE SETTINGS ON EACH SLOPE. WHEN A COUPLER SWITCH IS ENGAGED ON THE 9004 MODULE, THE 9004 MAIN CONTROL ADJUSTS THE CENTER FREQUENCY AND THE 9005 MAIN CONTROL ADJUSTS THE BANDWIDTH . BANDWIDTH AND CENTER FREQUENCY CAN ALSO BE VOLTAGE CONTROLLED. THESE RESPONSES CONTRIBUTE GREATLY IN AUDIBLY DEFINING THE C.M.S. MODULAR SYSTEMS UNIQUE SOUND.

VOLTAGE CONTROL OF FREQUENCY IS A STANDARD 1V PER OCTAVE WITH A FRONT PANEL CALIBRATION PORT. THE CONTROL INPUT MIXER HAS 4 INPUTS, THE RIGHT MOST BEING PRE-WIRED TO THE KEYBOARD CV BUSS. A 4 CHANNEL AUDIO MIXER HAS BEEN PROVIDED AT THE INPUT OF THE FILTER. THE FILTER WILL PRODUCE AN ULTRA PURE SINE WAVE WHEN SET TO SELF OSCILLATION AND WILL TRACK THE KEYBOARD ACCURATELY REGARDLESS OF TEMPERATURE OR HUMIDITY.

ELECTRICAL SPECIFICATIONS:

INPUTS:

  • FREQUENCY MODULATION: EXPONENTIAL - 1V PER OCTAVE
  • NOMINAL AUDIO INPUT: 10 V P-P +/-10V MAXIMUM
  • AUDIO INPUT IMPEDANCE: 100K OHM
  • CONTROL INPUT IMPEDANCE: 100K OHM

OUTPUTS:

  • CUTOFF FREQUENCY: 30HZ - 35KHZ
  • LOWPASS OUTPUT: 24Db WITH RESONANCE
  • HIGHPASS OUTPUT: 24Db WITH RESONANCE
  • GAIN: UNITY - NOMINAL 10V P-P, +/-10V MAXIMUM
  • ALL IMPEDANCES: 1K OHM

 

e-mail: filter@discretesynthesizers.com

Phone: 912-727-2195
©2004 Phil Cirocco