Are your synths on a diet? Is that thin drum sound bothering you? If you feel the need to fatten up your tracks a little (or even turn them into straight up noise) here is a list of our favourite “high cholesterol” analog warming and distortion devices.

Stereo saturation, “fattening” and distortion processors are surprisingly uncommon; producers, keyboardists and electronic musicians don’t have so many options when it comes to add those precious harmonics to their sources. This all seems really funny to me because, as an ocassional guitarist -well, more of a string breaker to be honest-, it’s oftentimes easy to encounter the opposite feeling once you go to the music store: if there’s one type of effect pedal where supply infinitely exceeds demand that has to be overdrive (and all of it’s close cousins: distortion, fuzz…). Overdrive is usually just a form of soft clipping, while the other two are more heavy handed variations of the same theme. In essence all of these three effect categories share a common characteristic: a very useful sound design ingredient called harmonic distortion -they’re just using different shades and amounts of it-.

In the days of tape recording, distortion was not really a feature, it was more of an unavoidable drawback that producers, musicians and engineers pretty much had to live with (just like noise, filtering or many other non-linearities were back in the day). Sure, distortion could be used as an effect sometimes, but when not wanted -for example, in classical or jazz genres- it was impossible to avoid in it’s entirety. In a similar way to recording mediums, the most common playback systems where based on technologies that also added distortion, filtering and noise -like vinyl records, cassettes or 8-track tapes-. Because of this, by the time that the music reached the final listener, the amount of added harmonics had increased exponentially so many times over the recording, duplication and reproduction processes, that the sonic imprint of the finished product was quite different from the original sound sources.

Today we have a very different situation altogether. Most -if not all- of the recordings we consume are recorded directly to a digital format in the first place. Many of them don’t even involve an analog mixer (which would add to the amount of distortion present in the final master) nor the tape medium, instead hitting an AD converter’s input very early in the creative process -and being stored as data from then on-. These files can now even be mixed and mastered totally in the DAW, without ever needing to go back to the analog medium again, other than for listening and monitoring. Low distortion and high sound-to-noise ratio chips and opamps are more affordable today than they ever were. And to top it off, everybody has a fairly high quality audio converter in his laptop or phone, with enough memory to hold the equivalent of an enormous LP collection, but without the added playback distortion and surface noise problems -and with a medium that doesn’t degrade the recording with each reproduction cycle-.

It’s quite a big change in such a short span of time and, to some people, a few of those former disadvantages of analog mediums and tools are now seen as something desirable. Our ears have become accustomed to these characteristic “drawbacks”, as they’re now part of the spirit and sonic aesthetics of 20th century recordings. While many artists and producers have embraced the clean sound of digital without fear, retro-mania is here to stay and the thirst for that old-school sound is as big as it ever was. Sure, there are many digital plugins that can achieve similar “sweetening” effects, but they often add other non-analog problems in the process (such as aliasing). Also they’re not the best if you need a hardware setup for live performance or a processor to compliment a mixer-centric studio.

So, if you want to add some of that old-school analog edge to your tracks -but would prefer to stay in the physical realm- or if you want to go even further with those harmonics (industrial, anyone?) here are our top picks for the best hardware distortion, saturation and warming tools currently available in the pro-audio market.



French firm OTO is no stranger to track sweetening devices. Their first product, the now classic Biscuit, tried to reproduce the bit-crushing and filtering present in old sampler AD and DA stages, bringing back to the present the sound of classic early digital devices like the Fairlight, the Akai MPC-60 or the EMU SP-1200. After their later take on retro digital reverb and delay processors -with their BAM and BIM fx units respectively- they more recently completed this trilogy with their first product featuring a full analog signal path: the mighty BOUM. 

Described as a “warming unit”, BOUM is a stereo desktop module that includes four saturation and distortion flavors from subtle to extreme: a soft clipper, an mosfet based circuit (producing tube-like asymmetrical distortion) and two variants of hard clipping/fuzz. But that’s not all! The unit also includes a very cool sounding compressor (with even negative ratios like some classic DBX units), a noise gate, plus lo and hi cut filters -to maybe tame those extreme harmonics a little-. And the coolest part is that all of this is totally recallable! Although 100% analog (processing-wise) the BOUM is digitally controlled, so it has presets -36 of them no less!- and it can also be automized via MIDI. It’s also the most affordable in this list! What’s not to like?

If you want a BOUM you can get one here!

PS: (Stay tuned, we might do a full BOUM review in the near future!)



After working for digital fx specialists Eventide as an engineer, Dave Derr created the Distressor in 1994 as the first product of his own pro-audio company, Empirical Labs. This versatile studio compressor could mimic legendary LA-2As and 1176s, with all that power packed in a modern 1u rack interface. It has since become a modern classic, found in studios all over the world.

The “Fatso” (Full Analog Tape Simulator and Optimizer) was Dave’s second product and its purpose this time was to emulate the desirable qualities of analog tape recorders. Although its height is only one rack unit too, the Fatso is stereo (unlike the Distressor which is mono) and it packs a lot of processing inside. It’s a compressor (that works by selecting between a few preset settings, perfect for recall and no-frills, “set and forget” operation), a soft clipper, a “harmonic enhancement” tool (via its selectable transformer out option) and a “warming” processor -its “warmth” section cuts the highs dynamically, achieving some of the same HF limiting effects that tape is known for-. Now in its newest version (EL7x), it even packs a new comp setting -called “Eleven”- that emulates an 1176 in 20:1 ratio. Given its price and rack form-factor Fatso is more of a studio piece, but if you want something relatively subtle and quite versatile, this is definitely an excellent addition to any control room.




You got to love Elysia. These germans are engineering innovators of the highest caliber. Instead of focusing on cloning the Neves, APIs and Universal Audios of the past -like most other pro audio firms do today- Elysia has always been very forward thinking while still keeping the analog ethos in their work. After designing SPL’s famous Transient Designer, Ruben Tilgner joined Dominik Klaße to form the company in 2005, and they’ve been creating amazing futuristic analog designs -in both rack and 500 series formats- ever since.

And Karacter is no exception. While a saturation or distortion unit is nothing new, the way these guys have implemented the idea is very clever. You have three types of distortion (soft clipping, fet distortion and “turbo boost”), filtering, a wet/dry mix, and the options for stereo, dual mono or mid/side operation. Also, if you have the rack mount version it even has a CV input to control the drive and mix parameters with -for example- your modular synth gear!




Don Hume, the man behind Niio Analog loves old-school bits of kit that tend to mangle and shape the signal in unorthodox ways, and his Niio Iotine -now in its fourth version-, is a testament to machines like the Paia Overdrive, Roland’s SIP-300 guitar preamp, classic console EQs or the input stage of some selected vintage samplers.

The Iotine can be some many things in one that we’re afraid to leave something out in its description: it’s a filter bank (containing 3 state variable 12dB/oct circuits), a saturator (with a choice of 16 different distortion circuits!), a compressor, expander, EQ and it even boasts a triggerable envelope and an envelope follower to modulate some of the parameters. It’s a bit more leftfield than some of the others processors in this list, and its feature set reminds me of the legendary Ebbe Und Flut from Schippmann. So, if you want something experimental, this one is for you!




The gnarly Analog Heat was recently revamped by the friendly chaps at Elektron Sweden, featuring a new oled screen, backlit keys and tougher, more durable encoders. Similar in concept to the Boum, Elektron’s Heat is a desktop unit with digital control, presets, and a selection of various distortion circuits (8 different ones!). It also features envelopes, following, LFOs and, last but not least, a very powerful multimode filter with 7 different shapes!

It also can be controlled and recalled via Elektron’s Overbridge technology from your DAW of choice, for perfect integration within a modern studio environment. The Heat is probably the machine that’s capable of the most extreme sonic destruction in this list, so if you wan’t to make a record inspired by Throbbing Gristle, Nitzer Ebb or Nine Inch Nails this is definitely a good choice to start with.


About the author: José -Pepe- Coca  is a musician, producer and audio engineer from Zaragoza (Spain). He has a PhD in Art and teaches Sound Systems, Synthesis and Mastering courses at CPA Salduie and SEAS. He has also worked as a sound designer for companies such as Elektron, Befaco or HelloSamples.