SGA1566 is a freeware vintage tube preamp emulation in VST/AU plugin format for Windows and Mac based digital audio workstations, released by Shattered Glass Audio.
The plugin emulates a vintage single channel tube preamplifier, featuring two 12AX7 tube amplification stages and a two-band Baxandall equalizer which can be placed either at the input or the output stage. The plugin also features two different CPU modes, offering improved stability and compatibility with older and less powerful machines. The low CPU mode is less CPU intensive, at the cost of a slightly less accurate simulation of the tube circuit. Check the entire BPB review here.
Check out the SGA1566 audio demo:
SGA1566 is available for free download via Shattered Glass Audio (1.12 MB download size, EXE installer, 32-bit & 64-bit VST/AU plugin format for Windows).