The front panel provides inputs for channels 1 and 2 (with selector switches) and controls for each of the 8 mic preamps:
(2) 70-80's era mic preamps, with pad and 48V switches.
(2) 80-90's era mic preamps, with pad and 48V switches.
(2) 90-00's era mic preamps, with pad and 48V switches.
(2) Trion mic preamps, each with pad, 48V, instrument mode, and "FIX" gain preset.
An innovative addition is the "FIX" button on each of the two Trion preamps. The "FIX" button engages a preset gain trim (user-adjustable via a trim pot). The combination of the front-panel input switching and the "FIX" buttons allow you to switch the first two preamps between one use (such as 2 calibrated overhead mics in the studio) and another ( such as a vocal chain setup) without having to re-set the input gain in-between.
The rear panel includes 8 microphone preamp inputs and a DB25 connector carrying the 8 line outputs. The unit is constructed with a robust power supply and uses high-quality components that are assembled and tested at our factory in Nashville, Tennessee, USA.
Our design staff, some of whom have been at the company since the mid-70s, researched our archives and re-created these designs using the accumulated knowledge of their analog design expertise. These circuits represent the "designers choice" among dozens of consoles that we have developed through the years. The details of each preamp were tweaked to capture (and sometimes accentuate) the character of the original mic preamps using modern components. In each case, the original intent was to provide the most transparent design possible with the available technology. On some recorded sources the differences will be subtle, while on others the differences will be quite noticeable.
TRION This preamp is based on a premium Lundahl transformer in an unconventional but inspired design that provides 70dB of clean gain. It also has the additional features of front panel inputs, instrument (hi-Z) selection, and an alternate "FIX" gain preset. With unmatched sound and configurability, this pair of preamps provides the backbone for any recording studio. They provide subtle character for lead vocals, clean gain for DI instruments, transformer saturation on close-miked drums, and recallability (using the FIX mode) for matched drum overheads. The TRION mic preamps are the culmination of decades of optimizations to accommodate sources with widely-ranging requirements. You can't throw anything at these preamps that they can't handle.
70s-80s A parallel discrete input stage provides 60dB gain using a static bias scheme. This preamp has an EIN measurement at the edge of theoretical limits, and is perfect for quiet sources where noise performance is an absolute priority. Paradoxically, this same preamp provided the hard-hitting sounds of 70s rock and R&B that put Harrison on the map. A true classic.
80s-90s This model is based on a single discrete input stage (63dB gain) using an active bias scheme. Providing slightly more gain and headroom than the 70s models, but with a similar character, this preamp is a "workhorse" design that has powered many incarnations of Harrison analog products over the years. This is an excellent low-noise, high-gain preamp that will transparently capture any source.
90s-00s Incorporating a single discrete input stage (63dB gain) and using a passive bias scheme, these preamps also incorporate FET-compensated headroom extension. This unusual design powered some of Harrison's later digitally-controlled analog consoles, and it is highly regarded for preserving the character of individual drums, acoustic guitar, and other percussive, harmonically-rich sources that need to "cut through" a mix. This circuit also differs from the others by using a parallel electronically-balanced output which we found was needed to preserve the original's character.