SGA1566 is a free virtual preamp VST/AU plugin from Shattered Glass Audio. It is based on a single channel vintage tube pre-amplifier schematic with some added tone controls and a stereo output. The pre-amp circuit is simulated in real-time to get an authentic analog sound so it hits the CPU quite hard, although there is also a lighter version available.
Use the SGA1566 plugin to get more warmth of your audio tracks or to saturate the audio with the tube overdrive.
It is available for PC and Mac in VST & AU format.
SGA1566 – Free Download