Thermionic Culture THE PHOENIX HG15 High Gain Valve Compressor - Manual (Page 9)

©Thermionic Culture Ltd, October 2013 8
5 Operational Hints
The HG15 is designed specially as a vocal compressor,
though it’s very much at home also as a track compressor,
using 2 together for stereo buss. Also great for individual
instruments.
When recording direct from a mic source, the MIC setting is
fine for most microphones, whether condenser (valve or
FET) or moving coil dynamic. However, PAD can be used for
high output mics that like a higher impedance input.
The TIME CONSTANT switch controls both attack and
release and settings are very much the preference of the
individual user. To start with, 3 is good for vocals, 1 for
violins, 6 for percussive instruments. Please let us know
your own preferences by email as this section may be
expanded or the settings changed.
The OUTPUT TRIM should be used at or close to max (0dB)
for cleanest results when going to a standard Line input. Set
lower if you’re driving the HG15 harder for some harmonic
distortion, or just to trim the level when compressing heavily.
The SIDE CHAIN feature on the HG15 has a significant
effect on the frequency response of the compression and
also the time based response.
It's commonly known that lengthening attack times on
compressors will allow transients to pass through whilst
triggering the compression less if desired. However part of
this effect is that low frequency impulses will also tend to
pass through un-compressed and this is partly what makes
slow attack times so popular. Low frequency impulses
contain a lot of energy which will trigger the compression
more easily than higher frequencies and they tend to decay
slowly as well. This can make the release time of the
compressor feel very slow and sluggish.