4-string Eurorack synthesizer with quadrophonic pickup - 122HP case
The ADDAC120QS is the Strings Quadraphonic system by ADDAC System, the most advanced version of the modular string ecosystem for Eurorack, housed in a 122HP case. It integrates a headstock and bridge, a handcrafted quadraphonic pickup, robotic plectrums, an automated mute, a rotary exciter, and an ebow slider, offering a truly versatile stringed instrument that can be played and controlled via CV, trigger, or MIDI, with independent outputs for each string.
The ADDAC120 forms the physical foundation of the system—a Headstock & Bridge module that accommodates strings with gauges up to .055. The strings are installed exactly as on a guitar: the user is free to choose their preferred string set and tuning. The headstock is equipped with 4 locking tuners to make string installation faster and easier; the string holes can also be enlarged to accommodate thicker strings.
The set includes a Bow Arch Attachment, which raises the two center strings, allowing a bow to reach each string individually, and Small Resonators, which are simple yet extremely effective at adding harmonics to the unwound strings. Each resonator added generates a new partial: as more are added, the timbre becomes progressively more complex, eventually producing results reminiscent of a bell’s sound.
The ADDAC122 is the system’s quadraphonic pickup, capable of capturing each string completely independently. Like the hexaphonic pickups developed in the 1980s for guitar synths, it avoids mono decoding of all strings together, offering more precise detection. The module functions as four independent pickups, each with its own preamp, dedicated volume control, and output jack; a post-volume Mono Mix output is also available, with all outputs at synth level.
Each coil is hand-wound by ADDAC System: these are stacked humbuckers with Alnico 5 magnets, wound with 20,000 turns of 44 AWG polyurethane wire, for a resistance of approximately 7.4 kOhm. The pickup height is adjustable via the mounting screws.
The ADDAC124 features a servo motor for each string, allowing you to pluck them independently via dedicated buttons, input triggers, or MIDI. In Pluck mode, the servo moves approximately 20 degrees for a full pluck; in Harmonic mode, the movement is reduced to approximately 10 degrees, lightly touching the string to bring out harmonics—by positioning the module at the midpoint, 2/3, or 3/4 of the string’s length. Up to 3 modules can be daisy-chained to pluck and generate multiple harmonics simultaneously. Twelve replacement picks are included.
Four 3-position switches allow you to control the module’s behavior: the top position disables triggers and MIDI, leaving only the buttons active; the middle position activates Pluck mode with all inputs functioning; the bottom position activates Harmonic mode, also with all inputs active. The height of the picks is adjustable via screws—lower for Pluck mode and raised by about 4 mm for Harmonic mode.
Inspired by the Mute system found on some Fender Jaguar and Bass VI guitars, the ADDAC125 uses a servo motor to raise and lower a sponge that, when pressed against the strings, slightly dampens their natural vibration, producing a tone different from a traditional palm mute. The module is passive and must be connected to an ADDAC124 Plectrums, either by replacing one of its servos or by operating in parallel using the dedicated splitter cable. For maximum effectiveness, position it as close to the headstock as possible.
The Rotary Exciter features a 7,000 RPM brushless motor that rotates a surface equipped with 4 magnets of opposite polarity, generating a rotating magnetic field. When the rotation speed matches the fundamental frequency or harmonics of a string, the string is forced to vibrate, creating sonic textures that would otherwise be impossible to achieve manually. A Speed knob and a CV input allow for nonlinear control of the motor speed.
The ADDAC127 features a sliding carriage for a standard ebow, which the user can slide back and forth under the strings. The included ebow features the “PianoBow” modification, with the feet filed down to get closer to the strings without touching them as it slides. The height of the Ebow is adjustable via four knurled screws. The Ebow can be removed and used elsewhere, although without the feet it is less practical on a traditional guitar.
Technical Specifications
€ 1.842,00 € 1.450,39 + VAT
Normally delivered in 10-15 working days
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