The Prodigal uses 3 Torroidal Power Transformers
instead of the cheaper option of a single one where all the
output rails magnetically couple. This means that the VU and
relay circuits are completely isolated from the analog audio
circuitry - for super silent running. A third isolated
transformer is dedicated only to the P48 supply. Supply rail
voltages produced are:
T1: +48 phantom
T2: +15, +9, -9, -15 audio
T3: +5 digital metering, +12 relay switching.
Note the Star Ground Post on the rear panel,
which is the only point where Safety, Analog, Digital,
and Chassis Grounds meet. From any point in the
Prodigal's circuitry, there is only one path back to
here, which eliminates internal ground-loops and current noise
from neighbouring circuit nodes. This simple idea can be
challenging to implement, but is a big factor in creating the
Prodigal's scarily quiet noise floor. The Monitor Section alone
boasts a signal to noise ratio of 104dB!
Keen observers will also notice there is no electric fan
to annoy you during mixing. Fans in audio gear, well, blow. The
Prodigal is designed to run cool, and only needs the four small
black heatsinks for the audio rails, to which an additional
cooling fin will be added later in the build process.