C544 User Manual



The C544 is a mono four slots colour processor. The C544 is fully compatible with the DIYRE Colour Format and The DIYRE Colour Modules.

The C544 is designed to process the line level signals from the DAW system or the other line level source.

Each colour slot has independent Drive/Trim control knob section and the Colour Module bypass switch – C1, C2, C3, C4.

Colour modules are connected in series. No parallel signal routing is possible. Signal will be affected first by the Colour Module 1 and passed to the next colour module inserted in the following colour slot.

The Master Output section has the +/-6dB master output trim, master bypass switch and the LED indicator.



2. The Drive/Trim Operation – Each Colour Module

Each Drive/Trim Colour Module section has the independent active Drive circuitry with +20dB gain which can be used to saturate the colour module. The Trim part of the section is placed after the colour module.

The Drive/Trim is using one dual gang potentiometer. If the Drive gain increases the Trim reduces the signal from the colour module by the same dB value. As a result, the absolute output signal level remains equal to the input signal.

Some colour modules can clip the signal due to the limited headroom or the used components – clipping diodes. In such case, the output level from the colour module may be lower than the input level.

The Drive should be used with caution. Some colour modules cut off the signal if driven too hard. In severe case, a high signal level may damage the colour module.

First Use of C544:

  • Set all Drive/Trim knobs to a minimum.
  • Set Master Output knob to 12 o’clock – 0dB
  • Set all switches downwards (C1-4, BP)
  • Make sure that input and output is connected to correct sockets on the back of the 500rack
  • Play the test signal or track and confirm that the signal pass from input to output
  • Switch the BP upwards; the LED indicator should be ON
  • Confirm that the signal pass from input to output
  • Switch the C1-4 upwards, if the colour modules are inserted the signal should be present
  • Use the Drive/Trim knob to achieve the desired level of saturation.
  • Use the C1-4 switches to A/B the signal
  • Use the BP switch to A/B the C544 operation
  • In case of difference in level use the +/-6dB Master Output knob to compensate for the level difference.


To be continued…