TK Audio BC2-ME User Manual
TK Audio Audio
TK AUDIO BC2-ME
Stereo Buss Compressor - Mastering Edition
Congratulations on buying the mastering version of one of the most transparent stereo buss compressors ever made;
manufactured and hand-assembled in Sweden and thoroughly tested before leaving the factory.
The BC2-ME provides smooth buss compression associated with one of the most famous buss compressors from the
mid 80’s. Mixing engineers call it the magic ‘glue’ when transparent compression strengthens mixes without
compromising clarity.
The BC2-ME provides just that kind of compression bringing cohesion and punch; equally useful for drum buss and
instrument compression. All controls of the new unit are now stepped for easier recall. Push buttons are also
illuminated. The main signal path is more or less the same as in the BC1mk2 but we have added a switchable
transformer balanced class-A output stage and also a function that adds extra even-harmonics to the signal.
The built-in blend control makes it easy to apply parallel compression by adjusting the mix of dry and compressed
signal. A mute-switch is provided for muting the dry signal making it possible to adjust the compression without
changing the blend control.
A switchable side-chain filter with 5 frequencies makes the BC2-ME less responsive to low frequency energy. The
external side-chain input makes it possible to have the BC2-ME pump to an external source. The BC2-ME will add the
magic ‘glue’ and make your mixes sound punchy and coherent.
THE PARAMETERS:
THRESHOLD: -20dB to +20dB in 41 steps. The threshold adjusts the level above which the signal is reduced. A lower
threshold means a larger portion of the signal will be treated. For optimal results make sure that the input level is high
enough.
RATIO: 1.25:1 / 1.5:1 / 2:1 / 4:1 / 10:1 / Hard. The ratio determines the input/output ratio for signals above the
threshold. For example, a 4:1 ratio means that a signal overshooting the threshold by 4 dB will leave the compressor 1
dB above the threshold. At the 1.25:1 / 1.5:1 and 2:1 setting a relatively subtle soft-knee compression is applied. At
4:1, the compression becomes more obvious, and at 10:1 the BC2-ME is basically a peak limiter.
ATTACK: UF (ultrafast) / 0.1 / 0.3 / 0.6 / 1 / 3 / 10 / 30 / 60 / 120mS. The attack setting defines the time it takes for the
compressor to decrease the gain and reach the level determined by the ratio. Faster attack settings means better
control of the transient part of the sound, but if set too fast the compressor might cut away more transients than
wanted. A good starting point is 10ms.
RELEASE: 50 / 100 / 300 / 600ms / 1.2S / Auto. The release setting defines the time it takes for the compressor to
increase the gain to the level determined by the ratio, once the level has fallen below the threshold. Higher release
settings will result in a less intrusive compression with lower distortion, but if set too high the compression might not
be effective enough. A good starting point is 100ms or Auto.
AUTO-RELEASE: Makes the release function time dependent on the duration of the signal peak. In practise it's a fire-
and-forget setting that behaves the same way as a classic British buss compressor used by many since the 80ies.
HPF: A 6dB/octave high-pass filter at 75Hz, 100Hz, 125Hz, 150Hz or 250Hz is applied to the internal or external side-
chain signal, making the compression less responsive to low-frequency energy.
IN: True bypass switch. The inputs will be feeded directly to the outputs via relays.
EXT SC: Engages the external side-chain input on the back of the BC2-ME. By using the external side-chain another
signal can control the behavior of the compressor; most commonly used by DJs for ducking - lowering the music
volume automatically when speaking. It’s also effectively used for ducking the bass track or background whenever the
kick drum hits by sending the kick track to the external side-chain input. For more information please read the section
about side-chain compression.