Synthesizers. com Rack Mount Systems

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User Rating is a company in the USA that makes classic styled custom analog modular systems and sells them over the internet! They offer pre-built systems such as the QSR8 and QSR24 (pictured above). The QSR8 is the basic setup, an 8.75" high frame which can hold 8 single-width modules. The QSR24 is just three QSR8's in a simple wood rack enclosure. They come with a selection of modules plus an optional QKB15S 5-octave studio keyboard which uses and converts MIDI to CV/Gate. You can also customize your own System by choosing which modules you want them to install for you.

The form factor is the same as Moog Modulars but with an upgraded power supply system. The systems offer hyper-modularity which allows any module to be placed anywhere without rewiring, including power modules. modules will fit into Moog modulars and the signal levels are compatible. A wide variety of modules offer a raw, analog sound, including stable oscillators that will track over many octaves, a 24dB ladder filter, a state variable filter, and a 14-bank fixed filter. The 24-step analog sequencers can be daisy-chained for more stages and offer unique control features not found on your typical sequencers.

The QSR Rack Mount Systems use the same traditional patching, routing, knob fiddling and scientific tinkering of old-school modular synthesizers, with all the benefits of today's technology! The user interfaces of most modules include reversible attenuators and mixers to minimize patch cable clutter, and to make patching more intuitive. These synths are perfect for anyone interested in learning to use analog synthesizers in their traditional form. These systems are expandable and affordable compared to those old and unreliable vintage systems! Also available in Portable and Studio systems.

Modules from

QSR8 Modules

  • 1) Q137 Power Control/Interface
  • 1) Q106 Oscillator
  • 1) Q107 State Variable Filter
  • 1) Q108 Amplifier
  • 1) Q109 Envelope Generator
  • 1) Q118 Instrument Interface

QSR24 Additional Modules

  • 1) Q104 MIDI Interface
  • 1) Q105 Slew Limiter
  • 2) Q106 Oscillator
  • 1) Q108 Amplifier
  • 1) Q109 Envelope Generator
  • 1) Q110 Noise Source
  • 1) Q112 Mixer
  • 1) Q116 Ring Modulator
  • 1) Q117 Sample & Hold
  • 1) Q124 Multiples
  • 2) Q125 Signal Processor

Other Modules

  • Q102 AC Power Interface
  • Q111 Pan/Fade
  • Q112 Mixer
  • Q113 8-Channel Mixer
  • Q115 Reverb
  • Q119 Sequencer
  • Q120 Connector Interface
  • Q121 Banana Jack Interface
  • Q122 Mini Jack Interface
  • Q123 Standards
  • Q124 Multiples
  • Q125 Signal Processor
  • Q127 Fixed Filter Bank
  • Q128 Switch
  • Q130 Clipper/Rectifier
  • Q131 Blank Single Panel
  • Q140 Fixed Filter Bank Aid
  • Q141 Oscillator Aid
  • Q142 Pedal Interface
  • Q143 Presets
  • Q146 Normalization
  • Q147 Distributor
  • Q150 Tran Ladder Filter
  • Q161 Oscillator Mixer
  • Q162 Filter Mixer
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Demos & Media

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Polyphony - Monophonic / Polyphonic
Oscillators - Q106 - Analog Oscillator with Sine, Triangle, Saw, Ramp and Pulse waveforms. QSR8 has one, QSR24 has three.
Q110 - Noise Source makes White, Pink and Low Freq. Noise
LFO - Q106 - Analog Oscillator with Sine, Triangle, Saw, Ramp and Pulse waveforms
Q117 - Sample and Hold
Filter - Q107 State Variable Filter - 12dB/oct Low/Band/High Pass and 6dB/oct Notch modes. Q116 Ring Modulator - combine two input signals
VCA - Q108 Amplifier - Gain controls with multiple input options
Q109 - Envelope Generator - Attack/Decay/Sustain/Release
Keyboard - 5-Octave Studio Keyboard (optional). Monophonic and Duophonic operation. Outputs pitch control voltage, gate, velocity control voltage, and a trigger pulse.
Memory - None
Control - Q104 - MIDI Interface (MIDI IN, Gate Out, Trigger Out, Pitch Out, Velocity Out)
Date Produced - Since 2000


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