At a glance, most of the Features of the TM112b are identical
to the TM112 Compressor; however, there
are certain differences. Like the TM112 the 'b' version has a long tradition
as dynamics section of input modules of large format consoles like the MAGNUM
V3 by adt-audio.
The regulation characteristic, huge control ranges,
and the extensive feature set make it possible to set up the TM112b from acting
like an aggressive FET compressor to a slow and cozy opto compressor and anything
in between. The module can replace many 'one purpose' devices and - like a versatile
dynamics section in a console channel is supposed to - can cover many applications
of a compressor.
Apart from handpicked ac/dc converters and faster response in the
PEAK setting of the Crest switch as well a longer integration time of the RMS
setting, the VCA compressor adds parallel compression in the module and the Auto-Release
function to the feature
set of the TM112.
In addition to many standard settings, the TM112b vca compressor can achieve
gain of 10 to 15 dB without loosing transients and natural sound performance.
By the extended range of the attack control, settings are possible that let the
peaks pass thru without regulation, while the 'breakdown' after the peak is compressed
effectively by a very short release time and deep regulation.
Crest Factor Settings
The TM112b is a feedforward VCA Compressor with
a variable AC/DC converter. The Crest switch modifies the characteristic of the
converter that determines the basic characteristic of the compression. The Peak
position selects operation as an extremely fast peak rectifier; in the RMS
position the RMS value of the input signal is calculated by an analog computation
circuit and used as control signal for the vca. With the peak setting, the compressor
regulation is controlled by the peak levels in the signal while in RMS
mode the loudness of the signal controls the compressor. In position M the
control signal combines the best of the two worlds; neither the hard response
of peak mode nor the slow reaction of the RMS setting are used but a
well designed balance in between.
Threshold, Ratio, Attack, and Release
Threshold, Ratio, Attack, Release are controlled independently. The Threshold control
that determines the begin of the regulation has a range from -32 dB to + 15 dB.
The Ratio control ranges from 1:1 to 20:1.
At 20:1 the compressor operates as a Limiter. The control range of the Attack
Time reaches from 0.1 to 30 ms; the Release
can be adjusted in the range from 50 ms to 3 sec.
Envelope for better Bass Compression
The Envelope control
makes it possible to compress low frequency signals with short release times
that avoid pumping. This is achieved by a special filter in the side chain combined
with dynamic modulation of the release time. Envelope reduces the problem of
low frequency distortion with short, pump-free release time settings that limit
the maximum compression.
Parallel Compression with SMOOTH and Soft Knee with SOFT
Both features are controlled by a single pot. The center position OFF disables
both functions. The Soft Knee range of the pot determines
the range of the transition around the threshold. Without Soft Knee, the compressor
applies the same regulation characteristic to all levels above threshold while with
a setting all to the left the regulation starts with a small ratio at the threshold
level and increases the ratio to the setting of the ratio pot over a range of
12 dB. While the effect of soft knee setting is low with small ratio settings, soft
knee makes possible to achieve higher compression with less side effects when
using high ratio settings.
The SMOOTH range of the pot adds the uncompressed input signal to the compressed
output. With high compression, the transients get more and more 'damaged' which
can be covered very well by adding the uncompressed - and therefore undamaged
- input signal. However, too much input signal reduces the loudness gain. All
to right the pot adds - 4 dB input level to the output. In most cases, a range
from -20 to -8 dB is the best choice.
Auto Release selects the automatic adaption of the release time to the density
of the program. The push-pull switch of the release pot controls this feature.
Auto release operates based on the release time setting and increases the release
with high density signals.
Autogain and Gain
Autogain is an analog computation circuit
that determines the gain reduction caused by the actual settings of threshold,
ratio and attack and adjusts the output gain to achieve constant output levels,
independent of the compressor's setting. The compensation is active if the theshold is below the internally adjusted autogain zero level. The factory standard setting is + 6 dBu / + 4 dBV. This value can be changed to your needs.
Autogain operates with less than 1 dB accuracy with fast attack times.
With longer attack times, the output level depends on the structure of the signal.
Since peaks pass thru the compressor without causing regulation with long attack time settings,
the peaks determine the output level, which cannot be calculated without establishing
another dynamic regulation parameter. The attack compensation is adjusted to
an experimentally ascertained value that results in a very good compensation
with almost all signals. Autogain can be switched off by the push-pull switch
of the ratio control. In addition, there is a manual gain control pot with +/-
Side Chain Insert
The switched Side-Chain Insert allows
using external equalizers and filters in the regulation loop of the compressor.
The push pull switch of the threshold pot activates the insert input. The signal
is always available on the insert output. Insert input and output are balanced
and can handle levels of + 30 dBu.
Since the TM112b as a feedforward controlled compressor, the side chain insert
input can also be used to control the compression by another signal. Feeding
the side chain insert input with the input signal of an equalizer that is installed
pre the compressor makes possible to use the side-chain function to switch between
'regulation post eq' and 'regulation pre eq'.
Gain Reduction Display
The gain reduction display is a LED chain with 5 LEDs and a display range for 20 dB. The first LED shows a gain reduction of 1 dB, followed by 3 dB, 5 dB and 10 dB.
The TM112 Compressor is a 2U ToolMod unit that fits into all ToolMod Frames. Horizontal and vertical versions are available.