IGS Audio Multicore is a three-band analog VCA compressor with an adjustable active crossover at 6 dB/oct slope — designed as a stereo dynamics processor for mix bus and mastering applications. The signal path uses only THT (through-hole technology) components; passive elements are matched in pairs for optimal L/R correlation; Carnhill VTB transformers on input (10 kΩ) and output (600 Ω). Dynamic range of 104 dB(A), THD+N of 0.08%, SNR of 90 dB(A) — mastering-grade parameters at 22 W power consumption.
6 dB/oct Crossover and Independent Per-Band Compression Without Phase Issues
The choice of 6 dB/oct crossover slope is deliberate. Steeper slopes (18 or 24 dB/oct) minimize band overlap but introduce phase shifts that are audible in the summed output. The gentle 6 dB/oct slope preserves phase coherence at the cost of a wider transition band — meaning each band picks up some content from adjacent frequencies, and the compression effect is smoother and more musical across the crossover region. Each of the three bands (Low, Mid, High) has an independent set of controls: Threshold, Ratio (2:1/4:1/10:1), Attack (0.1/0.3/1/18/30 ms), Release (0.1/0.4/0.6/0.8/1.6 s or Auto), and Gain. A Mute/ON/Bypass switch per band allows silencing two bands to monitor the content and bandwidth of the third in isolation — essential when setting crossover frequencies on complex material. Maximum gain reduction is –20 dB per band at operating level +4 dBu with headroom to +28 dBu.
Applications: Mix Bus, Mastering and Individual Tracks
On the mix bus, the Multicore controls dynamics per frequency range without inter-band influence — quiet midrange sources don't force low-band compression, and aggressive bass content doesn't pump the high end. On vocals, the High band compressor handles sibilance (4–10 kHz) without affecting the low and midrange dynamic — functionally similar to a de-esser, but with full control over the compression characteristics. On acoustic material (piano, strings, ensemble), per-band independent compression preserves the instrument's natural dynamic balance while evening out frequency extremes. Carnhill VTB transformers on both input and output contribute the subtle transformer coloration associated with Neve-class hardware.
KEY FEATURES
- Three-band analog VCA compressor — Low, Mid, High
- Adjustable active crossover, 6 dB/oct slope — no phase problems at band summing
- Independent compressor per band: Threshold, Ratio, Attack, Release, Gain
- Ratio: 2:1, 4:1, 10:1 (switched per band)
- Attack: 0.1 / 0.3 / 1 / 18 / 30 ms (switched per band)
- Release: 0.1 / 0.4 / 0.6 / 0.8 / 1.6 s / Auto (switched per band)
- Mute/ON/Bypass per band — isolation and monitoring of individual band
- Max gain reduction: –20 dB per band
- Carnhill VTB transformers on inputs and outputs
- THT signal path — through-hole components, passive elements matched in L/R pairs
- Input impedance: 10 kΩ (balanced)
- Output impedance: 600 Ω (balanced)
- Max input and output level: +28 dBu
- Dynamic range: 104 dB(A)
- Power: internal, 115/230 V AC, 22 W
- Shipping weight: 10 kg; made in Poland
TECHNICAL SPECIFICATIONS
- Type: three-band stereo VCA compressor
- Crossover: active, adjustable, 6 dB/oct slope
- Input impedance: 10 kΩ (Carnhill VTB transformer, balanced)
- Output impedance: 600 Ω (Carnhill VTB transformer, balanced)
- Operating level: +4 dBu
- Max input level: +28 dBu
- Max output level: +28 dBu
- Dynamic range: 104 dB(A)
- Max gain reduction: –20 dB
- Ratio: 2:1, 4:1, 10:1
- Attack: 0.1 / 0.3 / 1 / 18 / 30 ms
- Release: 0.1 / 0.4 / 0.6 / 0.8 / 1.6 s / Auto
- Frequency response: 10 Hz – 30 kHz, +0.3 dB / –0.3 dB
- SNR: 90 dB(A)
- THD+N: 0.08%
- IMD (SMPTE): 0.03%
- Crosstalk: 88 dB
- Power: internal, 115/230 V AC, 22 W
- Shipping weight: 10 kg
- Made in: Poland
