TK Audio BC501-GR 500 Series Stereo Compressor

500 Series compressor
The BC501-GR is a stereo bus compressor equipped with virtually all the features found in the large TK flagship BC1-THD. The BC501-GR adds a few extra features taken from the BC2-ME mastering compressor, such as extra ratios, a THD switch that adds harmonic distortion to the signal, and three HPF settings (80 Hz, 150 Hz, 220 Hz). All controls are "stepped" for easy and accurate recall. A dedicated Dry/Comp control allows mixing between the dry and compressed signal, and an external side-chain input (accessible via stereo 1/8" mini TRS jack) provides additional options.

Specifications
Power requirement: +110mA / -90mA (total)
Frequency response: 20Hz to 20kHz +/- 0dB
Frequency response: 20Hz to 80kHz + 0dB / -0.1dB
THD + N @ 1kHz: less than 0.005%
Signal to noise ratio: 95dB
Cross talk: -90dB
Input impedance: 24 kohm
Output impedance: 50 ohms
Max input level: + 26dBu
Max output level: + 27dBu

Threshold: -20dB to + 20dB in 41 steps
Makeup: 0 to + 20dB in 41 steps
Ratio: 1:25, 1.5: 1, 2: 1, 4: 1, 6: 1, 10: 1
Attack: 0.1, 0.3, 0.6, 1, 3, 6, 10, 30, 60, 120mS
Release: 50, 100, 300, 600mS, 1.2S and Auto (50mS / 2S)
HP Filter: 80Hz, 150Hz and 220Hz (-6dB / octave)
External sidechain input via a stereo 3.5mm TRS
THD circuit that adds even harmonics
Blend control from dry to compressed in 21 steps