Solid State Logic | SSL VHD+ | 500 Series Microphone Preamp

The Solid State Logic VHD+ Pre is an incredibly versatile 500 Series mic preamp that delivers ultra-clean SSL SuperAnalogue sound — with a twist. Its all-analog signal path is outfitted with SSL’s Variable Harmonic Drive (VHD) system. As you increase VHD input gain, the VHD circuitry introduces either 2nd or 3rd-order harmonic distortion (or a blend of the two). At lower gain settings, it adds gentle tube-like warmth or a touch of transistor-style edge. As you increase gain, the more extreme the distortion becomes, all the way to trashed-transistor grunge. From pristine clean to full-tilt overdrive, this gives you immense flexibility to forge signature sounds that make your recordings really stand out. 

What the controls do

The top section of the VHD+ Pre is fitted with three rotary controls: Gain, Drive, and Trim. The Gain control (labeled “dB”) sets the input level from +20dB to +75dB. The Drive control lets you select 2nd or 3rd harmonic distortion or a continuously variable mix of the two. The Trim control adjusts the output level for optimal level matching with downstream devices in your signal chain. This is important, as the VHD circuit can boost signal levels significantly. The bottom section of the VHD+ Pre module provides a switchable 15Hz–500Hz highpass filter, a hi-Z switch for mic impedance matching, switchable 48V phantom power, a Pad to for line-level signal processing, and a Polarity invert switch.

• Uniquely versatile mic/line preamplifier
• Ultra clean SSL SuperAnalogue preamp
• Front panel DI/Lin In input
• VHD system adds blendable 2nd or 3rd harmonic distortion
• Switchable highpass filter (15Hz–500Hz)
• hi-Z switch for high-impedance microphone use
• 48V Phantom Power with status LED
• Pad for use with line-level source material
• Polarity invert switch
• Requires compatible 500 Series chassis