C673-A Dynamic Range Compressor
The C673-A served as the initial prototype for the concept of the world's first programmable analog processor.

Based on McDSP's C670 and C671 modules from the McDSP 6000 series plug-ins, the C673-A model pushes the envelope further with all analog dynamics processing and a custom saturation circuit.

The C673-A Compressor brings the McDSP variation of the Fairchild 670 back into the analog domain. Like its predecessors, C673-A offers faster signal tracking to accommodate modern production styles, while still imparting a ‘warmth’ into the audio output.
  • All analog compression and saturation stages

  • Side chain processing

  • Sample accurate automation of analog processing

  • Included with APB hardware purchase
  • AAX Native, AU, VST3
Any electrified stringed instrument brings plenty of mixing challenges. Why not start out with a great tone and managed levels? Enter the C673-A compressor! Setup a threshold that is showing 6 to 12 dB of reduction on the VU meter (be sure the GR option is selected) during a louder section of the track. Dial the Time Constant to somewhere between 350 and 550 msec. Adjust Output to obtain a desired level.
If you are looking for a compressed vocal sound that does not sound compressed, the C673-A could be the ticket. Try to keep maximum compression amounts around 9 to 12 dB, and the Time Constant under 400 msec to insure you do not inadvertently ‘duck’ the vocal by causing a loud segment to not allow the compressor to recover an errantly compress a quieter section. Usually one does not seek saturation for a lead vocal, but if the singer gets too loud, the saturation from the C673-A might give the track the edge you were looking for.
Need to take the top off a mix? Just not the right vibe? Give the C673-A a try. Setup the threshold for 1 to 3 dB of reduction, vary the Time Constant value as needed, and apply a slight level adjustment with the Output control. Sit back and take in the orange and black awesomeness !!!
Compression action can be triggered by the input channel (IN) or a side chain channel (KEY). The signal triggering compression action is commonly referred to as the key input.
Signal level at which analog compression action begins.
The C673-A offers a 3-way VU meter that can show signal level input (IN), signal level reduction caused by the compressor (GR), and signal level output (OUT).
Compressor output (COMP) or compressor key input (LISTEN) may be monitored at any time. If monitoring compressor key input, it will be the audio channel selected by the Side Chain control (IN or KEY).
Time Constant
Rate at which compressor recovers from signal peaks that have exceeded the compressor threshold level.
Amount of gain applied to the signal post compression, but pre saturation circuit.
“I love the fact that I can automate analog compression, think about that - that’s like a dream come true!”
Tony Maserati
Grammy award winning mix engineer
Sound Examples
Drums 1
Drums 2
Electric Bass
Female Vocal
Male Vocal
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