Detail 01
Feed-forward or feedback VCA
Feed-forward reacts to the incoming signal and grabs faster; feedback reacts to the output and sounds softer, more gradual.
Product detailSKU #1302806632244
Rupert Neve DesignsPortico 543: 500 Series Mono Compressor
1/2
Independent shopping perspective
The Korena take
Feed-forward/feedback 500 Series VCA compressor with continuously variable controls. For engineers who already have a 500 rack and want hands-on, non-stepped compression.
Strong match
Who this is for
- Tracking vocals or bass where you set compression by ear
- Engineers who want to A/B feed-forward against feedback response on one source
- Mix bus or stem duty where slow release matters
Consider the trade-offs
When to look elsewhere
- Anyone without a 500 Series rack and power supply
- Stereo work — this is one mono channel
- Engineers who need recallable stepped controls for session recall
What matters in use
The specifications, translated
Catalog numbers tell only part of the story. These are the details most likely to change how this product feels, sounds, or fits into a setup.
Detail 02
Ratio 1.1:1 up to 40:1
Goes from barely-there level shaping to a hard limiter, so one unit covers glue and peak control.
Detail 03
Attack 20ms to 75ms
Even the fastest setting lets transients through, so picks and consonants stay intact rather than getting flattened.
Detail 04
Release 100ms to 2.5 seconds
Short release pumps with the rhythm; the long end holds gain down smoothly across a whole phrase.
Detail 05
Threshold -36dB to +22dB
Wide enough to compress quiet room mics or hot line-level stems without an external gain stage.
Detail 06
Separate input level and gain reduction meters
You can watch how hard you are hitting it and how much it is working at the same time.
Final check
Know before you order
- 01No rack, no power supply, no cables — a 500 Series chassis is required
- 02One mono channel; buy two and link-match settings by hand for stereo
- 03Distortion rises from 0.0006% bypassed to 0.02% engaged — audible character, by design
Product questions
Before you decide
Straight answers to the questions shoppers most often ask about this product.
01Does this work on its own or do I need a rack?
It needs a 500 Series chassis. The module has no power supply or connectors of its own — the rack provides power and the input/output jacks.
02What is the difference between feed-forward and feedback mode?
Feed-forward detects the signal before compression, so it responds faster and more precisely. Feedback detects after, giving a slower, more forgiving curve. Same unit, two behaviors.
03Can I use two of these in stereo?
You can run two as a matched pair, but you set each one by hand. Channel-to-channel crosstalk in a rack is better than 90dB at 15kHz.
04Is the attack fast enough for drums?
The fastest setting is 20ms, so transients get through. Good for adding body and sustain to drums, less suited to hard peak-catching on individual hits.
Reference
Full specifications
The complete catalog record, organized around the decisions musicians make when comparing gear.
1 detailsSound
- Frequency Response
- Main output, unity gain @ 150 kHz -3dB
2 detailsConnections & power
- Main Output Compressor Bypassed
- Better than 0.0006%
- Main Output Compressor Engaged
- Better than 0.02%
1 detailsSize & weight
- Noise Measured At Main Output Un Weighted 22hz 22khz Terminated 40 Ohm
- With gain at unity, compressor disengaged: better than 103dBu; with Gain at Unity, Compressor engaged: better than 92dBu
8 detailsOther
- Attack Range
- Continuously variable from 20mS to 75mS
- Crosstalk Measured Channel to Channel
- Better than 90dB @ 15kHz
- Ratio Range
- Continuously variable from 1.1:1 to Limit (40:1)
- Ff Fb
- Feed-Forward or Feedback VCA control
- Gain Range
- Continuously variable from 6dB to +20dB
- Release Range
- Continuously variable from 100mS to 2.5 Seconds
- Threshold Range
- Continuously variable from 36dB to +22dB
- Meters
- Monitor INPUT LEVEL and GAIN REDUCTION
