SSL G383 Logic FX Dual Mic Amplifier and Equaliser
SSL's G Series console sound, pulled out of the desk and racked into a single space of 19-inch steel.
Overview
The G383 is one half of SSL's Logic FX line, the company's late-1980s attempt to sell its G Series console electronics as standalone outboard. The companion G384 took the compressor. The G383 took the front end: two identical mic amplifier and equaliser sections in a 1U rack unit. SSL's own advertising pitched it as a way to "simulate the legendary SSL sound" on consoles made by other manufacturers, and to let existing SSL rooms extend their E or G Series capabilities without buying another desk.
Each of the two channels starts with a transformerless balanced input and an unusual feature for the era: a variable input impedance control sweeping from 600 Ω up to roughly 8.5 kΩ. That range changes how a ribbon mic or a vintage dynamic behaves depending on where you set it, and it's the detail most owners mention first. Gain runs from +6 to 72 dB. There's 48 V phantom power, phase reverse, insert send and return points on the rear panel, and a six-element LED level display reading the signal at the insert send.
The EQ is the other reason people seek these out. It's a four-band parametric. The outer bands are 12 dB/octave shelving sections with variable cut-off frequencies - the HF shelf tunes anywhere between 1.5 kHz and 16 kHz - plus boost/cut controls. The LMF band has continuously variable bandwidth, gain, and centre frequency. A -3 button divides that band's frequency range by a factor of three so it can work down in the LF region. A switchable variable highpass filter is included, and the whole equaliser can be taken out of the signal path entirely. There's also a Split button that lifts the filter stage from its normal pre-EQ position and re-inserts it immediately after the channel input.
One quirk to know before you buy: the EQ gain controls carry no cut/boost markings. Mix (July 1990, p.72) called SSL about it and learned the two centre bands are ±22 dB while the outer bands are ±20 dB - considerably wider than the reviewer's guess of ±15 dB. The same review warned that the EQ is smooth enough to lull you into over-boosting, and praised the preamps' sonic transparency on acoustic guitar in particular. That same Mix critique (July 1990, p.70) also noted that the internal circuit boards had been shrunk to fit the 1U chassis, but found the layout extremely clean and reckoned servicing should be no problem.
Solid State Logic built the Logic FX units at Begbroke, Oxford, and sold them through New York and Los Angeles offices in the US. The company's advertising from the period framed the range around four use cases: recording engineers and mixers making Logic FX standard rack gear, SSL studios extending their consoles, other studios chasing the SSL sound, and live sound mixers wanting studio-grade processing on the road.
On the used market the G383 turns up in studio clearance listings with some regularity. A 1994 Studio Sound classified offered one described as used once at £1,750, and the same unit appears at the same asking price in listings from 1996. It also shows up in album gear credits; a Mix-era session writeup lists an "SSL FX G383" alongside a Speck ASC-T and Massenburg DesignWorks EQs in a contemporary production rig. The model is often listed simply as "SSL Logic FX G383 dual mic amp eq," so searches using the Logic FX name will surface more than "G383" alone.
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