FATSO is an acronym for Full Analog Tape Simulator and Optimizer. When digital multitracking first became affordable, it took only one session using 16 tracks of ADAT to convince me that I didn't want a digital multitrack in my own studio. Last year, I found myself returning to the world of digital when I purchased a Tascam MX-2424 hard disk recorder, though I still like to track basics to an analog machine (see review in issue #22). But when the time comes for overdubbing, comping, and editing, the MX-2424's advanced facilities, ease of use, and pristine sound are compelling reasons for going digital. Unfortunately, that pristine sound isn't always the right thing. The beauty of analog tape is in its ability to tame peaks, round out the cutting highs, beef up the low end, and generally make harsh sounds more pleasing to the ear. All these things combined make up what we call "tape compression." It's an effect that sounds "right" to many of us. It makes things sound "warmer" and "bigger". It's something that many of us who've gone digital miss with our HD recorders. Instead, our digital recorders - however pristine they may sound - are "cold" compared to analog recorders. The FATSO is the first device I've heard that brings that wonderful sound of analog tape to the digital medium. It's a two-channel box that incorporates four processors per channel: 1. COMPRESSOR. 2. SATURATION AND DISTORTION GENERATOR. 3. WARMTH PROCESSOR. 4. TRANNY. As we all know, a normal compressor is designed to reduce the dynamic range of a track or mix - that's its primary function. But a compressor can also reduce the perceived high frequency content of the track or mix as a byproduct of this function. Here's how: Transients tend to be rich in high frequencies, so reducing the volume of these transients relative to the sounds around them makes the whole track or mix seem less high-endy. In other words, when a compressor clamps down on the transients, your ears focus less on the transients, and therefore you hear less high-end. Unfortunately, getting "musical" results out of a compressor usually means letting the initial peaks of these transient sounds get through. In other words, compressors tend to sound more natural when the attack isn't set too fast. With too fast of an attack, you end up with a lifeless track. But here's the quandary. When you let the leading edges of those transients get through while compressing what comes afterwards, you oftentimes end up with a track that sounds too "brittle." This is especially true when recording digitally without benefit of the band-limiting that occurs with saturation of analog tape. What you get is a "sharpening of the edges" as the leading-edges of the transients get through, with the "dulling" of everything else as the compression kicks in. This simultaneous sharpening and dulling is what accentuates the "bite" and results in the brittle sound. You could bring in an EQ to try to warm things up. By scooping out some of the high-end or even some of the high-mids, you can reduce the brittleness. Unfortunately, this usually results in the track sounding dark and muddy. Here's where the FATSO and its four processors come in.
The COMPRESSOR is a junior version of the much-acclaimed Empirical Labs Distressor. It features Buss, General Purpose, Tracking and Spank modes. You can choose any one of the four - or any one of the first three combined with Spank. That gives you seven mode options. Other than the mode selector, the only other control for the compressor is the input knob. The manual explains how to set up the compressor (along with the other FATSO processors) to emulate various classic compressors (LA2, 1176, dbx 160, SSL, etc.). The compressor sounds great, but if you wanted this box just for the compression, you'd be better off buying a Distressor with its many more controls. What comes WITH the compression is what makes the FATSO shine. The SATURATION AND DISTORTION GENERATOR adds lower- order harmonics, much like the sweet-sounding tube circuits in vintage gear. Analog tape is similar to tube circuitry in the way it distorts when saturated - 2nd and 3rd order harmonics are added. Because the output of the Compressor feeds the Saturation and Distortion Generator, the amount of distortion is dependent on how you set up the compressor. You can distort just the peaks or you can go all out and add significant amounts of "sweetness." The WARMTH PROCESSOR is most easily explained as a high-frequency limiter. Such a limiter would prevent the high-frequency content of a signal from going past a specified threshold. This behavior is akin to what happens when the high frequencies in a recorded signal react with the record-bias when the levels are too "hot," resulting in self-erasure of certain high frequencies. Despite this simple explanation, the user manual promises that the processor is much more complex than just a frequency-selective limiter. Listening to this circuit confirms this, as the sound seems to lose less high-end than the attenuation meters might imply. Also the processor seems to have an extremely fast response time - you don't hear any of the "clippy" attack that a normal limiter would pass before clampdown occurs. The fourth processor is the TRANNY, short for transformer. The transformer circuit emulates the transformers in vintage audio gear (NEVE, API, etc) and the tightly coiled wires inside tape heads. Transformers tend to add harmonics to low frequencies, making bass notes sound bigger, while rounding out extreme transients. With the Tranny inserted, extremely low notes that might have gotten lost cut through better, while the ear is still fooled into hearing the fundamental note. The Warmth Processor together with the Saturation and Distortion Generator emulate the unique band-limited response of saturating tape. After dialing in the Compressor, a bit of "warmth" and "sweetness" from these processors reduce the aforementioned "brittleness" you hear when those wayward leading edges of transients get through unhindered. The Tranny gives you additional round off and that rich low end that analog tape provides. As a package, these four processors make the FATSO an indispensable tool for making your digital recordings analog-warm without taking the life out of your tracks. Ever since getting the FATSO, I've tried it on just about everything I've tracked digitally (and on lots of things tracked analog), and most of the time, it's done wonders to the sound. Here are some of my favorite uses. On acoustic guitar, I use a teeny bit of Compression to bring out some of the sustain. A bit of Warmth tames the extreme string picks without reducing the air in the sustain, while Saturation still gives the string attacks enough clarity to cut through the mix. On electric guitar, I use a bit more Compression with lots more Saturation to give me that up-front sound that's so lacking with digitally-recorded guitar amps. For room mics, if I need to tame the cymbals while letting them and the other drums breathe out, I'll use the Compressor with a good amount of Warmth. This effectively tones down the cymbal strikes without losing the cymbal sheen or muddying up the drums. (I find this works best when I've got a separate set of overheads picking up the cymbals.) I recently worked on a song that had a spoken female vocal that needed to be mixed in with two spoken male vocals during the fadeout. The female vocal was getting lost. Using the FATSO, I added a ton of saturation to the female vocal. The resulting distortion was wonderfully thick and smooth, and it helped the female vocal stand out without it sounding odd. One additional point I want to make. Although the FATSO is marketed as an analog tape emulator, its uses are not limited to digital recording. Its various effects have a wide enough range (subtle, musical, extreme) that you may find it essential even if you are an analog- snob with nary a plan to record digitally. I paid $2012 for my FATSO. That may seem like a "fat" chunk of change, but I know of nothing else that can do the wonderful things this unit can do. Plus, you're getting two independent (but linkable) channels of magic. As soon as I can afford it, I'm buying one more... or maybe two more... or maybe... (www.empiricallabs.com)