We at DSPdoctor helped Dan at Great River design the MM20, so we have a bit more experience getting the unit intergrated into a studio enviroment than other dealers. We can easily design the patch bay and cabling layout for you! We are really good at removing all the guess work on how the MM20 will fill the centerpeice slot in your studio. Each situation is different, so give us a call or write an email to info@dspdoctor.com. We're here to help make your buying experience easy!  


The MixMaster 20 is a comprehensive analog centerpiece for your DAW based recording system. Tracking, editing, and mixing are all facilitated with this unit.


The MixMaster 20 includes four transformer coupled high gain low noise microphone preamplifiers that work with any type of microphone, ribbon, dynamic or condenser. Polarity and phantom power switching is provided on the front panel.


Line and instrument duties are handled by transformer coupled input bridging amplifiers with wide gain ranges, suitable for anything from keyboards to tape machines.


Each of the four input channels has a balanced insert point as well as four auxiliary output mix sends. Each channel may also be fed to the main stereo mix bus.


Mixing duties are handled by the four input channels plus the 16 transformerless line input channels. Each of these channels has fully controllable level and pan settings to the stereo mix bus. Mix settings can be stored and recalled via the USB port and a GUI compatible with most digital recording programs is in development to make the MixMaster 20 an automated analog mixer.


The mixing is done passively, with the summing gain provided by transformer coupled mixing amplifiers. The balanced output of this stage is available as a patch point for the insertion of compressors, equalizers or other signal processing equipment. The return is also transformer balanced and feeds the Penny & Giles stereo fader and output line amplifier, also transformer coupled.


Control room monitoring functions are also provided. These include a versatile solo system, multiple speaker system selector and level control, mix replay monitoring and talkback. Talkback feeds the cut outputs and dims the main monitoring system to aid communications and minimize feedback.


Input Channels 1-4 feature four newly designed ultra high resolution, ultra low noise microphone preamplifiers as well as:
    •    Insert patch Engage/Bypass control
    •    Mic / Line switch
    •    Mic / Line level controls
    •    Phantom power
    •    Post-insert direct outputs
    •    Solo and Mute controls
    •    Output level control
    •    Two auxiliary output [A/B] level controls with Engage/Bypass
    •    Pan
    •    Transformer coupling on the inputs and the outputs

Input channels 5-20 are fully featured on the Channel Select Matrix. These inputs feed a pair of transformers before the Master Stereo Amplifiers. They are completely accessible through the units Digital Encoder and Matrix Select. There are horizontal meters for Pan and for Level indication on the matrix selected channel.

Other features of the MixMaster 20 include:
    •    Completely transformer coupled master stereo bus
    •    Transformer coupled inserts
    •    Patch Engage/Bypass control
    •    Tape Return Engage/Bypass control
    •    Alternate Speaker [A/B] output selector
    •    Full monitoring output section with cue output and Talk Back which feeds the cue output.
    •    Master Bus features a full throw Penny & Giles fader with VU meters.

In development is a GUI plug-in that will allow digital control and recall of MixMaster mix settings from popular DAW software packages.