Specifications

Chapter 7: BF-2A 41
Chapter 7: BF-2A
The BF-2A is a vintage-style compressor plug-in
that is available in TDM, RTAS, and AudioSuite
formats.
Meticulously crafted to capture every nuance of
the legendary LA-2A tube studio compressor,
the Bomb Factory BF-2A provides the most au-
thentic vintage compression sound available.
How BF-2A Works
Designed and manufactured in the early 1960s,
the LA-2A achieved wide acclaim for its smooth
compression action and extremely high quality
audio signal path.
Originally designed as a limiter for broadcast
audio, a Comp/Limit switch was added to LA-2A
compressors after serial number 572. The subse-
quent addition of a Comp (Compress) setting
made the LA-2A even more popular for use in
audio production. However, the switch was in-
conveniently located on the back of the unit next
to the terminal strips and tube sockets in the
original version. In the BF-2A plug-in, the
switch has been placed on the front panel, where
you can make better use of it.
The heart of the LA-2A is its patented T4B Elec-
troOptical Attenuator, which provides the com-
pression action. The T4B consists of a photo-
conductive cell, which changes resistance when
light strikes it. It is attached to an electro-lumi-
nescent panel, which produces light in response
to voltage. Audio (voltage) is applied to the light
source, and what happens as the audio converts
to light and back to voltage gives the LA-2A its
unique compression action. (Yes, the Bomb Fac-
tory BF-2A preserves all the subtle characteris-
tics of this unique electronic circuit.) After com-
pression, gain brings the signal back to its
original level. The LA-2A’s gain comes from a
tube amplifier, which imparts further character
to the tone. In fact, it’s common to see engineers
using the LA-2A simply as a line amp, without
any compression applied to the signal.
One beautiful side effect of the LA-2A’s elegant
design is that it’s easy to hear the compression
action. When the BF-2A’s two knobs are set
properly, you know you got it right. It’s a great
unit for learning the art of compression!
BF-2A