Vintage-topology Rackmount

Heritage Audio is pleased to announce its new range of rack mountable analog summing mixers. Comprising vintage quality sound with sophisticated routing options, they are the perfect partner for hybrid setups, integrating analog gear with your DAW.


The MCM-20.4 employs a unique configuration, offering 16 input channels arranged into 2 subgroups of 8, plus 4 more channels wired hard left and right in pairs. Each front channel features center detent Pan and Fader concentric controls plus balanced insert and mute switches.

4 auxiliary sends are provided; being AUX 1&2 mono sends, while 3 is Stereo. Sends can be done Pre or Post Fader. Master send levels are provided as well.

The insert send points always have the signal present, so they can alternatively be used as direct outputs for recording without additional patch bays.

Each group has its own stereo fader and balanced insert point and the 2 stereo subgroups are passively summed into the master bus. The gain is restored by means of a 73 style Class A, transformer coupled, mic preamplifier, featuring a total of 4 transformers (1input & 1output in each channel of the stereo bus).

The master section also has its own insert point on balanced gold plated XLRs.

All connections on the back are made by DB 25 connectors following the Tascam protocol, with the exception of the master bus connections, which are by dedicated gold plated XLRs.


The smart summing topology employed in the MCM series of mixers allows for an impressive headroom and surprising low noise figure for a 20 channel, vintage topology mixer. Special care has been taken on improving crosstalk and self-noise figures from those on vintage designs in order to accommodate the new MCM mixers into the digital era.

The transformer based Class A output stage is able to deliver a full +26 dBu output.

  • Channel Input Impedance: Greater than 20 kΩ.
  • Maximum channel input level: Greater than +26 dBu.
  • Maximum insert return input level: Greater than +26 dBu.
  • Maximum insert send level: Greater than +27 dBu, able to drive 600 Ω.
  • Maximum output level: Greater than +26 dBu into 600 Ω.
  • Frequency response: ±0.5 dB 20 Hz to 20 kHz.
  • THD + N: Not more than 0.07 % from 50 Hz to 10 kHz at +20 dBu output (22 Hz to 22 kHz bandwidth) into 600 Ω.
  • Noise, all faders up, all subgroups in, measured at the main output, better than -80 dBu.
Customer Ratings