Description
The Modstar 4075 offers the Studio Electronics recreation of the classic 4-pole Arp 4072 low pass filter now made as a discrete analogue voltage controlled module for eurorack systems. Using 6 pairs of hand matched transistors and fixing the 12kHz design flaw of the original, the new 4075 offers unsurpassed sonic quality and a range of tonal options.
Based around a 24dB/octave cascaded transconductance low-pass filter, the 4075 is one of the most popular filters in the Boomstar range; and it’s no wonder because there’s nothing quite like it! With Frequency and Resonance as its main two controls, you can set your harmonics and push them past self oscillation for explosive low to mid-range power and depth.
The AMP, the 5089, and the 3003 are Class A circuits. They draw more current from the +12 rail than from the -12 volt rail. If the system power supply is under-sized, hum or buzz may be heard. In that case, larger filter capacitors and/or a larger power transformer will be needed. The 4075 draws equally from both rails, and is more immune to hum.
Specifications
Potentiometer Potential
Three attenuverter and four attenuation pots control the FREQUENCY, RESONANCE, FREQ CV 1, RESO CV, FREQ CV 2, INPUT and OUTPUT, delivering smooth, detailed and complex expression.
Switch it Up
Classic Minimoog FULL and HALF strength filter frequency keyboard/voltage tracking for rounder low end with brilliant highs.
Patch it Up
Seven patch points: 1 V/O, FREQ CV 1, FREQ CV 2, RESO CV, INPUT and 2x OUTPUT direct the deepest manipulation.
All Controls and Patch Points
FREQUENCY – Adjusts the frequency, or cut-off of the filter.
RESONANCE – Adjusts the resonance of the filter. *
FULL HALF TRACK – Switch between full and half keyboard/voltage tracking.
FREQ CV 1 – Frequency control voltage 1 input attenuverter.
RESO CV – Resonance control voltage input attenuverter.
FREQ CV 2 – Frequency control voltage 2 input attenuverter.
INPUT – Adjusts the audio input.
OUTPUT – Adjusts the audio output.
1 V/O – One volt per octave control voltage input.
FREQ CV 1 – Frequency control voltage 1 input.
FREQ CV 2 – Frequency control voltage 2 input.
RESO CV – Resonance control voltage input.
INPUT – Audio input.
OUTPUT x2 – Audio outputs.
Vitals
Size – 12hp
Depth – 39.7mm with ribbon cable attached
Power Usage – 23mA, 30mA (+12 / -12)
* From 7:00 (0) to 9:00 our “Negative Resonance Saturation” adds beefiness, boosting the waveform amplitude and taming waveform transients; set to 9:00 to achieve the cleanest tone possible.
