The VHD+ Pre 500 Series Module takes the uniquely versatile VHD based preamp design from SSL's industry leading studio console, Duality, and puts it into a housing to be used in studios of any size. Immensely flexible for recording and processing, the VHD+ Pre Module can deliver super clean SSL SuperAnalogue‚Ñ¢ grade recordings, but also boasts a switchable VHD mode. SSL's patented VHD system uses a totally analogue signal path to impart signals with rich harmonic saturation. By increasing the VHD input gain, the Variable Harmonic Drive process introduces 2nd or 3rd order harmonics, or a blend of both, to the source signal. At lower settings, the saturation can be gentle and valve-like, or give a subtle and slightly edgy transistor character. Increasing the gain makes the distortion more extreme, until at the highest settings, plunges in to all-out trashy transistor distortion. Whether you're looking for traditional, super-clean SSL preamplification, looking to add subtle colour, or all out transistor smash, VHD will change your outlook on studio mic preamplification. With the VHD+ Pre Module, you get unparalleled flexibility from a studio-grade preamp. Key features SSL SuperAnalogue‚Ñ¢ grade preamp 2nd order harmonics (valve warmth to extreme distortion) 3rd order harmonics (transistor edge to totally trashed) Absolute control via 2nd and 3rd order harmonic blend Variable Harmonic Drive (VHD) in/out switch Switch-able LF Filter +48V phantom power Phase invert switch PAD switch Hi-Z switch