TapeOp Reviews 2-BUS+

Review by Thom Monahan for TapeOp Magazine

Do people still argue about analog summing versus in-the- box mixing? I’m sure somewhere in Internet-world, the flames are still raging. I can see both sides of the long- running argument, but it’s kind of like pontificating on hiking. It’s great to talk about how nice places are, but at some point, you have to actually go and find out where you like to walk. And people just take different paths.

I’ve definitely had great experiences in both worlds — analog summing and ITB mixing — but find myself happier with analog summing for the sonics and the gain-staging convenience it provides. Plus, I really do like using analog hardware while mixing. It just feels easier and more intuitive to me. Once you settle on a workflow, a great external summing bus is an invaluable tool that is a pleasure to have around.

Released in 1999, a venerable staple of the world of analog summing is the Dangerous Music 2-BUS, a 16-input active summing amp renowned for its neutral but musical tone, massive headroom, and stable, detailed imaging. Dangerous sold a lot of these units, and when they went to build the new version, they did much more than strap a couple of features onto the old architecture. The 2-BUS+ is a redesign with major improvements to the circuitry, as well as a new op-amp in the summing circuit that Dangerous claims is cleaner, with lower noise and crosstalk. I found the new 2-BUS+ to be solid and incredibly musical, while still retaining the original’s openness and clarity that allows the unit to get out of the way of your signal.

The 2-BUS+ integrated into my studio seamlessly. I plugged it in and kind of forgot that it was there, except for the fact that 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.

Although the new 2-BUS+ is still a 16-in, 2-out summing amp at heart, it now features three Color circuits that add a whole new dimension to Dangerous’s design ethos: Harmonics, an odd/even distortion generator; Paralimit, a FET limiter (my fave) that blends in an expertly crushed layer of your signal; and X-Former, which uses a pair of customized CineMag transformers to provide some seriously voodoo’d-out core saturation. Coloration is normally processed in that order, but Paralimit can be put in front of Harmonics if desired. X-Former always stays in the stereo output signal path, but Harmonics and Paralimit can be assigned separately to a pair of inputs so stems can be processed with those alone. The routing is easily accessible with front-panel buttons. The control of these tone circuits is pretty nice and thoughtfully done.

The front panel features activity LEDs for the 16 inputs, mono buttons for inputs 1-2 and 9-10, and assignment buttons for Harmonics and Paralimit on inputs 13-14 and 15-16. Each Color circuit has a level knob and engagement switch. There’s also an insert/bypass button for the external stereo insert loop (which is after all of the Color circuits in the signal chain). Rounding out the features is a stepped attenuator that goes from -4 dB to +6 dB in 0.5 dB increments for the output. Rear connections are made with DB-25 or XLR for the 16 inputs, and XLRs for the stereo hardware insert, main and monitor outputs, as well as a stereo expansion input to allow stacking multiple units. It’s packed back there.

The 2-BUS+, as with everything from Dangerous Music, is built rock-solid and seems to be made from last-foreverium. Knobs are sturdy and have a nice amount of friction, so adjustments can be made quite precisely. With no Color circuits engaged, the unit sounds as wide-open and distortion-free as you could hope for. In my experience, the summing amp never gave me a moment of grief. If something in my system were to fail, the last place I’d look for issues would be in the 2-BUS+.

There are two major approaches with summing amps. It basically breaks down into colored versus neutral. Certain summing amps seek to provide the desirable saturation that you might get from mixing through all the circuitry of a large- format console, while others just try to stay out of the way, be as neutral as possible, and just provide an external framework for your DAW’s outputs to run as widely and with as much fidelity and musicality as they can. Dangerous summing amps have always had an incredible amount of headroom. I’ve used a D-Box for ages and have summed the outputs of two pegged consoles into it with no issues at all — not a chirp, nothing. Dangerous summing amps are nearly impossible to overload. Distortion is not a language that they speak.

With this reboot of the 2-BUS, Dangerous knew that they wanted the best of both of these worlds and they needed Color, with a capital C. Initial discussions between members of the company’s inner circle must have been hilarious. Chris Muth, Dangerous Music’s co-founder and main designer, has spent his entire career trying to design noise and distortion out of his circuits, and now, like the Godfather, they kept dragging him back in. Design started with John Monforte, an old friend of the company and a great analog designer who has worked with a number of well-regarded audio brands. After an extended back-and-forth dialing in the alpha-stage ideas and circuits, these Colors were brought to Muth for refinement and integration into the overall design. I think Chris may still have been working out some demons, because the results are definitely unlike other approaches to the same old thing.

There’s no way around it; these are gnarly heavy-duty flavors that need to be learned. These saturation tonalities are really bold additions to anyone’s palette. In a recording world obsessed with saturation and distortion, these Colors are very unique takes on sounds that we all think we know and understand. But it’s best to forget what you’re thinking when you look at the names of those Color circuits. The manual suggests to start slow and to bring them in gently, and keep going until you can really hear what they’re doing — which is very good advice. These knobs go way, way, way too far; no one will want to print mixes with these Colors cranked.

Don’t dime the X-Former knob and expect a gentle purr, this is a maniacal asphalt milling machine that will come up and grind apart your mix. Then too much Harmonics will destroy it from the bottom. Extremely program dependent, both of these Colors can be incredibly ugly if overexposed, but just the right amount is magic, especially the X-Former on small speakers. In seductive opposition to the others, Paralimit is an opioid that is way too easy to overuse. It sounds so good, but the comedown, when you realize you’ve overdone it, is a reality check.

Dangerous intentionally designed the range of these knobs so that you can really hear how each Color circuit reacts on different material. That way, you can turn up each knob until it’s blatantly obvious what the circuit is doing to your mix, and then roll back the effect to a usable range. You have to listen, learn what’s going on, and then back it down to where you need it. Dangerous implemented this expanded knob-range with care and precision, because the knobs are good and tight, and they don’t feel at all jumpy in the lower regions where they will tend to settle as you make all of your important level decisions.

Paralimit is possibly the easiest to get your head around; it’s a sound that anyone who has used and abused a FET limiter will recognize. But this Color doesn’t collapse the image and doesn’t get dark. It’s fun, and it’s an easy technique to employ, but it’s not easy to get this to right where it feels like a real extension of the mix across the whole frequency range. Dangerous’s use of heavy pre-emphasis to rail the circuit results in a beautiful, addicting backdrop of detail that doesn’t suffer from the disappointing wobble and flutter that normally corrupts low end in a mix that’s subject to heavy FET limiting. You definitely have to discipline yourself not to bring it up too much. It can easily become the bulk of what you’re listening to, and like the loudness wars of old, it can lead to a mix that is intense but fatiguing. Easily the preeminent Color circuit, this feature in a standalone box would be incredible, but then you’d miss all the functionality that you get from being able to readily assign it to a drum or vocal stem.

X-Former is a truly different sounding effect. It’s not quite a pleasing distortion when turned way up, but it’s really useful in practice. It reminds me a little of the Z.Vex Machine guitar pedal, an effect that generates distortion in the slopes of the cycle and not in the peaks. The pedal is meant to sit in-between stacked, active dirt/fuzz pedals. It helps note definition but sounds truly horrible on its own. But what the pedal does is magic. The X-Former circuit has that same kind of tonality and specialness. I found that just a touch of it helped the low end in mixes translate better on smaller speakers and gave mixes a bit more clarity. It did catch me a few times when I forgot to turn it off and was working the next day with different material and heard it exposed. I know that it’s unlike any other kind of saturation effect I’m employing on the way into the 2-BUS+, and maybe the fact that it’s so different adds to its usefulness. It’s a bold effect with some very interesting twists. Muth says, “What I did was somewhat counterintuitive. Part of it involves a saturation driver blowing signal the wrong way on one of the transformer windings to make it a controlled overload that can be dialed in. Relatively simple in theory, but tricky in practice.”

Harmonics is definitely the most subtle Color — until there’s way too much — and the toughest to decipher. I initially approached it thinking it would sound like an old-school Aphex Exciter, which always seemed to me like it was slathering a layer of icing on your program — way too sugary and sweet, and too much ruins the cake. The odd/even distortion that the Harmonics circuit generates seems to emanate from within the program material and doesn’t seem quite as driven by transients. It’s a trickier bit of business that’s best used when tracks feel “simple” but already have a fair amount of high-frequency content.

All of these Color circuits are definitely tools to be learned, not simple one knob fixers. They won’t save a lifeless mix, but they provide a wide variety of tonality that can give music more life out in the real world on multiple systems. It sounds a bit silly, but once I was using the 2-BUS+ Colors on a regular basis, I noticed the most difference in playback on mobile phones; there’s more depth and clarity with the Colors engaged. Now, that might not be any kind of playback system we aspire for people to listen on, but it’s a real one. Mobile playback is how people seem to hear things for the first time these days. And trust me, a bit of Paralimit and X-former goes a long way to getting the most out of those small speakers.

I do have a few minor quibbles about certain things, but they come from my own particular workflow. I do wish that the mono buttons were placed on channels 7-8, and 15-16, instead of on 1-2 and 9-10. I tend to start with a stereo mix, then break out stereo submixes, and then eventually get to single mono tracks. Therefore, in my daily routine, with multiple Pro Tools sessions coming in from different studios, and flipping back and forth between tracking and mixing, the 2-BUS+’s mono assignments mean I need to double-check the mono buttons and think twice about DAW routing when I open each session for the first time. If, on the other hand, you’re someone who likes to break out mono tracks (like kick and snare) immediately, then the 1-2 and 9-10 mono buttons will make perfect sense. Regardless, it’s not that difficult to reroute DAW outputs appropriately. In terms of the aesthetics of the 2-BUS+, I wish it were easier to see button on/off states. The LED indicators go from dimly lit to brighter, which means you have to really pay attention if the 2-BUS+ is not directly in eyesight. But truthfully, both of these issues are things that make you up your protocol game.

Working on music is always about cultivating studied knowledge and careful thought, alongside intuition and go-for-it rule-breaking. On our road to recording bliss, we’re striving for a flow of moments of no thought — if it sounds good it is — but with the prudence that we’re not somehow screwing ourselves sonically in the long run. So with that in mind, crank those Color circuits, but please, check yourself before you wreck yourself, and turn them down. 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.