Eurorack filter based on CEM/AS3320 used in modular Synthesizers.
Table of Contents
This eurorack-modul is designed for modular-synthesizers as substractive filter.
The filter is build around that IC: AS3320, a clone of that old CEM3320.
All parts are common available and DIY-friendly designed.
- Modul Frontpanel
- Modul Backside
There are five 3.5mm jacks available for patching audio- and CV-signals.
Jack-Name | Function | Comment |
---|---|---|
IN | audio-input | Level adjustable between 0 ... 2 |
ResCV | CV-input for resonance control | Level adjustable between 0 ... 10 (only positiv voltages are used, negativ voltages are clipped) |
Mod. | CV-input for modulation control | Level adjustable between - 0 + |
OUT | audio-output for HP/LP/BP mode (12dB/octave) |
audio-output attached to switch HP := High pass mode LP := Low pass mode BP := Band pass mode |
LP24 | audio-output for LP mode only (24dB/octave) |
Low pass only audio-output with 24dB/octave (simultaneously usable with 'OUT') |
There are six potentiometers with following functions:
Poti-Name | Function | Comment |
---|---|---|
Frequency | Cut-Off frequency 20Hz to 20kHz | Filter cutoff frequency, range: min := < 20 Hz max := > 20kHz 12 o'clock position := 440Hz |
Track | Keyboard-CV tracking potentiom. | Keyboard-CV tracking adjustable 0 := None 1 := 1V/octave |
Res. | Resonance potentiometer | Resonance adjustment 0 := None 10 := maximum, self oscillation 12 o'clock position := starting oscillation |
IN | Audio input-level attenuator | Level adjustable between 0 ... 2 0 := No audio signal from IN-jack 1 := audio signal Out-level is 1 * IN-level 2 := audio signal Out-level is 2 * IN-level |
ResCV | Resonance-CV attenuator | Resonance-CV attenuator 0 := None 10 := maximum |
Mod. | Modulation-CV attenuverter | Modulation-CV attenuverter, controlling the amount and polarity of modulation - := negative modulation + := positive modulation 0 := no modulation |
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size:
width: 8HP
depth: 40mm -
power:
5Volt, 0 mA
+12Volt, 25mA
-12Volt, 25mA -
frequency range: 20Hz to 20kHz.
-
frequency CV scale: 1V/Oct.
-
signal input, AC-coupled signal path.
-
modulation inputs, DC-coupled signal path.
-
signal input impedance: > 50kOhm.
-
signal output impedance: 470 Ohm.
-
CV-Input impedance: 100kOhm.
Hardware:cc by-nc-sa 4.0 (details)