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A colorful and unique analog bus processor that’s perfect for the modern studio

Review by Paul Vnuk Jr.

Since 1969, England’s Solid State Logic (SSL) has reigned as one of the world’s most respected manufacturers of high end recording consoles. It’s only a slight exaggeration to say that SSL is largely responsible for the sound of recorded music from the 1980s onward. In addition to their legendary large format consoles, over the past decade SSL has been catering to the growing project studio market, launching tabletop products such as the compact X-desk and the even smaller SiX mixer (announced March 2019). SSL also offers straight-up microphone preamps and signal processors housed in traditional 19″ rack mount units as well as 500 Series modules.

SSL Fusion debuted at AES New York 2019. Fusion is a bit of a departure for SSL as it’s filled with fresh designs in a ground-up build. I’ll tell you right up front: this device ranks high on my Best of AES short list.

Meet the new SSL Fusion!

Fusion is a stereo analog bus processor that packs six distinct functions into a single 2U 19″ enclosure. The unit was designed in the UK like all SSL products, and manufactured in China.

Fusion is designed for stereo processing. A single set of controls affect both the left and right channels equally. You can of course process a mono source if you wish, but you cannot alter the left and right signals independently.

All connections are made on the backside of the unit, where there are two pairs of balanced XLR I/O connectors. One is for the main stereo ins and outs, and the other addresses a flexible insert point (explained below).

Fusion presents a synergy of six processes: Highpass Filter, Vintage Drive, Violet EQ, HF Compressor, Stereo Image, and Transformer. Processes typically have no more than one or two controls each. A grand total of 13 colored knobs, 8 backlit push-buttons, and a stereo LED meter are conveniently arranged on a good-looking brushed gray metal faceplate.

The Fusion signal path moves from left to right, beginning and ending with I/O level controls detented at the 12 o’clock position, each providing 12dB of gain. A stereo input level LED glows when input peaks exceed +27dBu.

Highpass Filter

The input stage is followed by a stepped highpass filter on an 18dB per octave slope, with settings of Off, 30, 40 and 50Hz.

Vintage Drive

According to SSL, Vintage Drive is a “non-linear harmonic enhancement circuit” that adds harmonic distortion and saturation to the signal. Two knobs, Drive and Density, control the effect. The Drive knob controls the overall amount of the process. The Density knob at twelve o’clock sets a balanced blend of high and low frequency enhancement. Clockwise favors higher frequency harmonic content, and counter-clockwise adds thickening and weight. This section has its own saturation clip LED as well as a bypass button.

Vintage Drive can absolutely deliver overloaded analog circuit-style saturation if you want it. However, this is not your usual heavy handed, make-it-fuzzy kind of process. It’s more EQ-like and sonorous, adding varied degrees of harmonic sheen and weight. Vintage Drive is an addictive process. Once engaged, you won’t want to turn it off—somehow the mix just sounds better—more gelled, more exciting. Engaging the process causes a volume boost; use the I/O controls to rebalance the signal, and use the bypass button to level-match dry and effected signals.

The New SSL Violet EQ

It can be argued that SSL’s single greatest accomplishment lies in the field of console EQ. The debate over which EQ is better: the Black or the Brown, resulted in most modern SSL consoles offering a choice of both! Fusion introduces SSL’s first new EQ design in 25 years, the Violet EQ, a phase coherent, two-band shelving EQ. The low shelf control is purple and the high shelf comes in fusion-fuchsia. The shelves offer stepped choices of 30-50-70-90Hz and 8-12-16-20kHz respectively, each with ±9dB of attenuation. The sound is gentle overall, but Violet can still add a fair amount of low thump and glorious air. Bypass button provided.

High Frequency Compressor

Fusion’s HF Compressor section is not your typical bus compressor. Rather, this simple dual-control process performs compression of high frequency material only, to smooth out harshness and bite. It can even offer tape machine-style high frequency rounding. Its two orange controls are a ±10 threshold and a variable crossover spanning 3-20kHz. An LED indicator lets you know if maybe you’re getting a bit too heavy handed with the effect! A bypass switch lets you compare and contrast. Note: there is no make up gain control. In use, HF Compressor works great for taking just a little off the top. HF Compressor works hand-in-glove with Violet EQ’s high shelf, to craft the perfect top-end signature for your mix.

Stereo Image

The last full section on SSL Fusion is Stereo Image. Again, this is a two-control, bypassable section that uses mid-side (MS) processing to alter the perceived width and depth of your tracks. The blue knob on the left is ‘space’, which boosts or cuts low frequency information from the side signals ±12dB. The blue knob on the right alters the width of your image by adding or subtracting the side signals ±6dB. This is my second favorite feature after the Drive section, and just like with Drive, a little bit goes a long way.


The last tone shaping control on Fusion is a 600Ω, 1:1 transformer that can be added last in the chain with the push of a button. Use this to add classic low-end punch, harmonic richness, and a bit of sparkle to your sound.

Insert and Master Bypass

Fusion’s insert allows you to patch
external hardware into the process chain, such as the famed “Magic Box” SSL XLogic G Series bus compressor. In my studio, I use the A-Design HM-2 Nail tube compressor (reviewed October 2011) for  all my master bus work. The HM-2 integrates perfectly with Fusion. The insertion point can be placed pre-Violet EQ or post-HF Compressor, and it can also be set for MS use. A master bypass control for all processes is available with two modes: bypass all, and bypass everything after the input level control.

Fusion Conclusion

In today’s world of increasingly in-the-box work, SSL Fusion checks all the right boxes for adding analog mojo to your master bus. Easy to use and possessed with a broad throw of tonal sweetening capabilities, this is a very impressive piece.

Price: $2495

More from: Solid State Logic, www.solidstatelogic.com/fusion