Definitive Analog Summing + Color


Diagram Gallery

Surpassing The Original

Dangerous Music invented the stand-alone analog summing mixer with the ground-breaking 2-BUS back in 1999, and now we’re redefining mixing yet again with the brand new 2-BUS+. With a redesigned analog summing circuit that exceeds previous specifications, the 2-BUS+ delivers unsurpassed imaging, dimensionality, punch and headroom. While the 2-BUS+ active summing sounds incredible on its own, it now includes three innovative custom color circuits that provide a vast array of flexibly routed tonal options. Harmonics is a euphoric odd- and even-order distortion generator; Paralimit is a hard-hitting FET-style limiter; and X-Former is a pair of Cinemag output transformers with an exclusive core-overdrive circuit. With it’s elegantly straightforward buttons and knobs, the 2-BUS+ puts endless combinations of robust analog sound at your fingertips. Meticulously developed by our hands-on team and brilliantly designed by the legendary Chris Muth, the 2-BUS+ embodies our dedication to sacrificing nothing in order to deliver the very best analog products available.

Unveil Your Sound With Active Analog Summing

Analog summing is a vastly misunderstood topic, but it doesn’t need to be. First, when multiple converters share the workload of getting your sounds from digital into analog, you’ll hear improved articulation and clarity across your mix. Once in the analog realm, these individual channels are electronically summed together with what’s called an “active analog summing circuit.” Unlike passive summing boxes that require huge amounts of make-up gain to restore the lost audio, or line mixers masquerading as “summing mixers,” the active electronics in the 2-BUS+ result in what Dangerous users describe as “a huge soundstage,” “holographic sound,” and “audible three-dimensionality.” Panning is wide and precise, reverbs spacious and deep, bass powerful and engaging, treble and mids articulate and interesting. The 2-BUS+ unveils all the details that bring your creations to life.

Emulation Impossible

Many analog processors – from delays and reverbs to EQs, compressors and more – have been beautifully modeled in the digital realm, but analog summing remains impossible to emulate digitally. We’ve all experienced the frustration of a mix collapsing when relying on a single digital master fader to handle it all. The middle gets crowded, panning becomes blurry, reverbs lose dimension, and soon the mix just lacks appeal. And despite promising ad campaigns, analog mix bus emulation plugins just add distortion to the master fader, actually making problems worse. By summing individual tracks or subgroups of tracks (often called “stems”) with the 2-BUS+, you get crystal clear sonic imaging and a wide-open soundstage. No matter how high your track count, all your recorded audio, software instruments, samplers, effects and plugins will sing with the detail, punch and clarity that only real analog summing can deliver.

Three Real Analog Tone Circuits

When it comes to adding analog color to your mixes, the design team at Dangerous has developed three totally original all-analog circuits: Harmonics, Paralimit and X-Former. Because these circuits are physically built into the 2-BUS+, you get a versatile selection of analog colors while never leaving the lush, open analog mixing environment.

Harmonics – Add the euphoric sound of an analog circuit on the edge of distortion to your whole mix, or to individual channel pairs. Carefully tuned to generate the perfect mixture of odd- and even-order harmonics, this effect runs parallel with the unprocessed signal so you can dial in just the right amount of tone. The top end subtly simmers, the bass gently growls, and the whole sonic image warms up in ways that only a real analog circuit can offer.

Paralimit – This is a FET Limiter set to stun. An original Chris Muth design inspired by the famous 1176 Limiting Amplifier “all buttons in” trick, you get an infinite ratio setting flooded with analog top-end. With its blend knob and assignment buttons, Paralimit gives you instant parallel compression, in stereo, in the analog domain, on the full mix or on a stereo stem – a flexible set-up that otherwise requires complex patching, careful level matching and significant amounts of analog outboard gear.

X-former – Last in line are a pair of customized Cinemag transformers with Chris Muth’s totally unique approach to driving the core. Switch them in for the solid, punchy sound that makes older analog consoles so loved, then turn up the X-Former knob to drive the core of the transformer in a way that’s totally unique to the 2-BUS+. X-former is all about dialing in just the right amount of classic analog console color whenever it’s called for.

Effortless Analog Parallel Processing

Because you can effortlessly assign Harmonics and Paralimit to the whole mix or to individual channel pairs, instantly flip their patching order, and blend them in with the original signal at the twist of a knob, the 2-BUS+ provides incredibly flexible parallel processing without any outboard gear or fussy patching. With the ability to switch in the on-board customized Cinemag transformers, as well as any outboard processors you like on the switchable stereo insert, you’ve got nearly limitless options all accessed from the uncluttered front panel. Whether you choose to run it pure and clean, blend in just a hint of delicious analog flavor, or push it into the red-zone, we’ve put the choice back in your hands when mixing.

Making The Analog Investment

When you buy analog equipment, you’re making a real investment that will hold its value for decades.  Analog technology is time-tested.  It wont need an expensive upgrade, become incompatible with your computer or DAW, or start crashing. No matter what music production system you’re using in ten, fifteen, twenty years, the superior summing capabilities and timeless analog tone processors of the 2-BUS+ will always be a relevant, compatible and valuable centerpiece in your studio.


  • 16 channels of the world’s best active analog summing, that even surpasses the original.
  • Three distinctive analog color options: Harmonics, Paralimit and X-Former.
  • Effortless routing and blending of analog color circuits via elegant user interface.
  • Switchable stereo analog insert for easy outboard gear integration.
  • Massive sounds, sacrificing no detail.
  • Crystal clear sonic imaging and three-dimensionality.
  • Endless headroom for modern digital signal levels.
  • Stepped output gain control for exact recalls.
  • Both XLR and D-Sub input connectivity.
  • Audiophile-grade components throughout.
  • Hand-assembled in the USA.

Note: Dangerous Music, Inc. publishes actual measured specifications, not theoretical numbers derived from data sheets published by chip manufacturers.

Max Input Level > +28 dBu

THD+N @+4dBu: 1KHz, unweighted, 22Hz to 22kHz < 0.0048%

THD+N @+22dBu: 1KHz, unweighted, 22Hz to 22kHz < 0.0026%

IMD @ +4dBu: < 0.0038%

IMD @ +22dBu: < 0.0021%

Crosstalk rejection: > 108dBu @ 1KHz

Noise at Unity Gain: 22Hz to 22KHz: < -86dBu
Noise at Nominal Mix Setting: 22Hz to 22KHz: < -91dBu

Frequency Response: Flat within 0.1dB from 10Hz -50kHz

Input Impedance: 25K Ohms Balanced

Output Impedance: 50 Ohms Balanced

Replacement Fuses: AMERICAS: 90-120VAC 2 Amp Slo-Blo fuse. EUROPE: 200-260VAC 1 Amp Slo-Blo fuse

Choosing Your Summing Amp:

Since the creation of the Dangerous 2-Bus many manufacturers have released “summing box” products. Choosing one can be confusing, but if you ask 2 questions it becomes easy.

1.  Is it really a summing amplifier, or is it a line mixer?

A true summing box designed to be a back-end for a DAW mixer will be “fixed gain and fixed pan,” because the fader and pan controls are in the DAW software mixer. You do not want to repeat these functions in the hardware domain because a) you lose your recall capabilities and b) you are running your audio through unnecessary electronics which will degrade the sound.

If it has pan pots and/or level controls on it, it is a line mixer, not a summing mixer, despite what the front panel might say. A line mixer is perfect if you need to sub-mix keyboards or a bunch of mic preamps to stereo, but is not the best option when mixing a track from your DAW.


2.  Do I want  a clean or colored signal path for my mixing?

The short answer is you want options. Many manufacturers have a signature tonal coloration to their sound, incorporating components like transformers or tubes into the design. These components can sometimes shape the sound in a pleasing way, but you are stuck with that sound for everything you do. We chose to make the tone and color optional with the 2-Bus+ by designing three original analog color circuits that can be selected and adjusted as you need them. Suppose the transformer is great on one song but not right on another – you can simply disengage it with the press of a single button. Or suppose you like the harmonic stimulation, but want less of it. Other summing amps do not have this option; they hold you hostage to a single sound.

A true mastering-style summing amp will let all of what you recorded come through into a clean, high-headroom environment for the summing process. We at Dangerous have a deep background in designing and building mastering consoles and monitor controllers. With our approach to summing you can insert color where, when and how you choose with the onboard processors in the 2-Bus+, or with outboard gear and plugins. All options remain open, the best of all worlds.


A note on passive summing:

There are two types of passive summing devices: powered and non-powered. Non-powered summing amps simply employ a resistor network feeding a pair of busses. This process by its nature loses a considerable amount of level, requiring a high-gain amplifier (microphone preamplifier) to bring it back up to usable line level. Non-powered boxes require the user to insert a separate outboard mic pre for this makeup gain.

Other products have the amplifier built in, appearing on the outside like an active summing device but in fact employ the same non-powered summing as described above.  You can often tell when non-powered summing is being used by a high input channel count (32 or 48 inputs) because the parts cost only pennies, as opposed to having expensive active receiver amplifiers on every input.

We have found through years of experience and testing that this non-powered approach is not the ideal way to handle this task, and that an active design using balanced receiver amplifiers, summing op-amps and line drivers yields the most exceptional performance.

Not having an active balanced design creates several potential problems:

-A balanced receiver provides common mode rejection (CMR) while a passive resistor network does not. Good CMR is key to low noise performance.
-A balanced receiver allows isolation of the D/A converter’s ground from the audio ground of the summing amp – passive does not.  This could lead to poor crosstalk rejection, which means poor imaging.
-Active design also allows for a local ground reference for the inputs, which is the same ground reference as the summing op-amp. All these things contribute to a clean, quiet, low-distortion device that is stable.

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Check out our 2-Bus+ Reviews HERE


  • fab

    Fab Dupont

    Mix Engineer

    The Dangerous Music equipment is the centerpiece of my mixing rig. Everything I do goes thru a Dangerous Monitor, 2-Bus, Master and BAX EQ. Everything.

  • junior-sanchez-client-thumb

    Junior Sanchez


    “The 2-Bus offers every person that’s ever wondered or dreamt about working on a large format console that advantage of actually having that sound, that headroom, that sonic mass.”

  • chris-blackwell-client-thumb

    Chris Blackwell


    The PARALIMIT and X-FORMER appear to be magic knobs. Special mention goes to the PARALIMIT because it does that lovely thing of bringing up the general ambience without slamming the track, something I particularly love on drums.

  • TapeOp2

    Thom Monahan

    TapeOp Magazine

    “The overall sound of my mixes just seemed a little more robust and clear. If the original 2-BUS was a superhighway for sound, then the 2-BUS+ is one that’s been freshly repaved, and I just got right back on and drove. “

  • mike-crehore

    Mike Crehore

    Co-owner and Producer at Dubway

    I know Dangerous Music’s quality products from using the Dangerous 2-Bus on every mix I do. I can’t really work without them. I love the 2-Bus.

  • TapeOp2

    Thom Monahan

    TapeOp Magazine

    “For our journey, the 2-BUS+ provides the perfectly-paved superhighway, with a solid signal path and plenty of interesting detours to get us where we’re going.”

  • barry-rudolph

    Barry Rudolph

    Mix Magazine

    Mixing down a stereo pair [on the 2-Bus]…you’ll have more headroom and dynamic range, a wider stereo spread and clearer sound…than mixing inside Pro Tools.

  • dave-minehan-client-thumb

    David Minehan

    Guitarist for The Replacements, Producer at Wooly Mammoth Sound

    I’ve been producing bands since the early 80’s, and my constant evolution of capturing great audio productions has led me straight to Dangerous Music.

  • mqdefault

    Dave Rideau

    Mixing Engineer

    “The 2-Bus is a critical part of my setup. It replaces the console… I just love that sound.”

  • barry-rudolph

    Barry Rudolph

    Mix Magazine

    Mixing down a stereo pair [on the 2-Bus]…[is] just like… mixing Pro Tools track outputs on an analog desk.

  • jeff-juliano1

    Jeff Juliano

    Mix Engineer

    “I was using another brand of summing amp and thought I was happy with it, but as soon as I plugged in the 2-Bus I was floored.

  • jaquire-king

    Jacquire King

    Producer/Mix Engineer

    The 2-Bus is the sonic equivalent of a large format analog console.

  • Jeff Juliano

    Jeff Juliano

    Mix Engineer

    “The optional color circuits just gave me the sound of an SSL or Neve console in just 2 rack spaces… The low end punch, depth and width is just insane.. Im blown away!”

  • ryan-greene

    Ryan Greene


    On comparison mixes, I was prepared for the console to sound better than the 2-Bus, but I didn’t really notice a difference between them.

  • jeff-anderson

    Jeff Anderson

    EQ Magazine

    The difference in the stereo image of my mixes with the 2-Bus is pretty staggering.

  • pablo-arraya1

    Pablo Arraya

    Mix Engineer

    The Dangerous 2-Bus is extremely clean, has huge headroom, and it’s easy to use. The harder I hit the 2-Bus the better it sounds. I love this box.”

  • f-reid-shippen-client-thumb

    F. Reid Shippen

    Mixing Engineer

    “I tried every single summing box, and chose the Dangerous 2-Bus. It does what it’s supposed to do and doesn’t get in the way, which is really nice. If it’s good enough for Ted Jensen and Greg Calbi, it’s good enough for anybody.”

  • david-kahne1

    David Kahne

    Producer/Mix Engineer

    With the Dangerous 2-Bus, the final product sounds like when I’m mixing on a great large format console.

  • michael-barbiero

    Michael Barbiero

    Producer/Mix Engineer

    I just love the way…the 2-Bus…sounds. Anyone who’s trying to mix in-the-box without analog summing is missing half the picture.

  • dirty-south

    Dirty South


    The 2-Bus is amazing, it adds so much space and clarity to the mixes.

  • rob-carranza-72dpi

    Robert Carranza

    Mix Engineer

    “There’s such a noticeable benefit using the 2-Bus compared to mixing in-the-box.

  • SOS Mag

    Frederick Noren

    Sound On Sound Magazine

    “It’s way more versatile than most of its competitors – and so much more than just another ‘summing box’.”

  • jeff-anderson

    Jeff Anderson

    EQ Magazine

    The 2-Bus has…tons of headroom—about double what I would get from my console.

  • david-kahne1

    David Kahne

    Producer/Mix Engineer

    My mixes sound better on the 2-Bus than just mixed in the box: that was what made me choose the Dangerous summing amps.

  • ryan-greene

    Ryan Greene


    Because of the stem mixing for video games I was doing, I tried the Dangerous 2-Bus and my large format analog console went away very quickly after that!

  • blank-client-testimonial

    Charlie Peacock


    I feel like I’m working in half the time now. The Dangerous 2-Bus has definitely sped up what we do.

  • ryan-greene

    Ryan Greene


    I think the mixes sound fantastic on the Dangerous 2-Bus. And it’s infinitely faster and easier to work this way.

  • michael-james-client-thumb-2-2

    Michael James


    The thing that’s great about the 2-Bus for me is that the ‘mastering aesthetic’ of the Dangerous gear allows me to keep the coloration that I have in its pristine state, rather than adding to it.

  • craig-duman

    Craig Duman

    Video Game Sound Design/Music, Snowblind

    The Dangerous 2-Bus and Monitor ST were installed at the same time, immediately I could hear a big difference. I was very, very impressed.

  • alberto-rizzo-schettini

    Alberto Rizzo Schettino


    Dangerous Music contributes to the magic and vibe my clients relate to when they think of my studio.

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2-BUS+ Manual