TK Audio BC2-ME User Manual

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 leav ing the factory.
The BC2-ME provides smooth buss compression associated with one of the most famous buss compressor s 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 se ttings 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 fire­and-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 side­chain 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 use d 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.

L+R: When engaged the side-chain signals are summed to mono before hitting the threshold detectors meaning that
the compressor will be 6dB more sensitive to the centre information of the mix. That usually means kick drum, snare
drum, bass guitar and lead vocals. In most cases L+R should not be used.

THD: Adds extra even-harmonics to the signal. (around 0.5%)
CLASS-A: Selects the transformer balanced class-A output stage for a more vintage tone like a fat, punchy low-end

response with more mid character.
STRAIGHT MUTE: When engaged the uncompressed signal is muted; useful when doing parallel compression and

just want to listen to the compressed signal.
GAIN-REDUCTION METER: 20 LED’s shows the gain reduction in 0.5dB steps.
MAKE-UP: 0 to 10dB in 41 steps.
BLEND: Straight to compressed sound in 23 steps. Turning the knob clock-wise will mix the original signal with the

compressed signal. For more information please read the section a bout parallel compression.

STARTING PRESETS
MIX BUSS
The main purpose of the BC2-ME is to act as a bus compressor and it does it very well.
AUTO-RELEASE MAGIC
One of the true unique features of the BC2-ME is the auto-release setting and its ability to glue the mix together. The

auto-release is a good starting point when setting up the compressor for 2 buss duty. Adjust the Threshold until 2 to 3
dB of compression is shown by the meter. It's all it takes to glue the mix together.

Ratio: 1.25:1, 1.5:1, 2:1 or 4:1
HFP: 150Hz
ATTACK: 10 ms
Release: Auto
Blend: Comp

POP MIX COMPRESSION
For more obvious compression a fast release should be used. Adjust the Threshold until it shows about 3 to 4 dB of

compression on the loudest parts of the song.
Ratio: 4:1
HFP: 150Hz
ATTACK: 10 ms
Release: 100 or 300 ms
Blend: Comp

DRUM
The BC2-ME can go from subtle to pretty slamming compression on a drum buss and here are a few good starting

points. Make a habit of adjusting the Make-up gain until the compressed signal is equally loud as the uncompressed
signal, and toggle the Comp in button to listen what's actually happening to the drums when they are compressed.

A TOUCH OF DRUM COMPRESSION
The effect should be very subtle and just make the drums come together without adding altering the kick or snare

drum. Adjust the Threshold until the compression meter shows abo ut 2 dB of gain-reduction.
Ratio: 2:1
HFP: 150Hz
ATTACK: 3 ms
Release: AUTO
Blend: Comp

TIGHT DRUM COMPRESSION
To tighten up the drum buss without altering the drums too much a low ratio should be used. Adjust the Threshold until

about 3 or 4 dB of compression is done.
Ratio: 2:1
HFP: 150Hz
ATTACK: 10 ms
Release: 100 ms
Blend: Comp

HARD DRUM COMPRESSION
Applying hard drum compression will alter the sound of the snare drum and cymbals but in a dense mix that might be

the right thing to do. Adjust the Threshold until about 5 to 6 dB of compression is shown.
Ratio: 4:1
HFP: 150Hz
ATTACK: 10 ms
Release: 50 or 100 ms
Blend: Comp

VOCAL RIDING
Lead vocals usually need a bit of volume automation to cut through a dense mix - an important and time consuming

job. Due to its ultra transparent compression the same job can automatically be done with the BC2-ME. The trick is to
use a low Ratio and fast release, and set the Threshold until about 4 dB of compression is done.

Ratio: 1.5:1 or 2:1
HFP: 150Hz
ATTACK: 10 ms
Release: 50 ms
Blend: Comp