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Page 2: API The Box

Analogue Console By Hugh Robjohns
Published January 2014

Masters & Monitoring

The central portion of the console panel is given over to the output masters and monitoring facilities. The three aux send masters (two mono and one stereo) are adjusted via three rotary controls, each providing +6dB of gain at the fully clockwise position. Each output also has an AFL button to check what is being dispatched. Two more rotary controls are provided for the artist cue mix, the first controlling the contribution level from the stereo programme mix-bus and any selected two-track inputs (see below), while the second acts as a master output-level control. Again, an AFL button is also provided, and the four aux sends and stereo cue outputs are accessed physically via another AES59 D-sub on the rear panel.

The central control section is impressively spec'd and provides for switching between two sets of monitors.The central control section is impressively spec'd and provides for switching between two sets of monitors.The monitoring section source signal is selected with five push buttons at the top of the panel, accessing four separate stereo two-track inputs (connected via an AES59 D-sub) in addition to the stereo program mix bus. The four two-track signals can be auditioned individually or in combination, but are overridden (muted) whenever the program input is selected.

Usefully, these same four two-track inputs are available to the artist cue mix, selected with a second set of buttons either individually or in combination. A fifth button, corresponding with the control room's monitor program selector, is also labelled 'Program'… but it isn't! This button actually routes the output of the control room's monitor selector to the Cue mix, which means it will carry the stereo mix-bus signal only if the Program button is pressed for the control-room monitor source as well. Otherwise, the Cue feed will be whichever two-track sources are selected for the control room. This arrangement is convenient if you want the artists to hear what the control‑room monitors are playing with minimal button-pushing, but it can be quite perplexing if you aren't aware of the Cue source label's ambiguity!

Earlier I mentioned that The Box could mix 22 inputs simultaneously, or 28 with some clever patching. Here's how: since all four two-track inputs can be mixed together into the Cue bus, the Cue bus outputs can be patched via the rear panel directly into to the mix bus external inputs and — hey presto! — 28 inputs to the stereo mix-bus. This is yet another example of the supreme versatility of this unassuming little console.

Returning to the control-room monitoring, the selected two-track or stereo mix-bus source is automatically replaced with the PFL/AFL signal whenever a solo button is pressed, and this is the signal displayed on the two VU meters (where 0VU equates to +4dBu). By default, the solo section operates in PFL mode with a ±10dB level trim control, and three push buttons clear any soloed channels, engage destructive SIP, or the non-destructive stereo AFL modes.

The monitor section controls also include Mono, Dim and Cut buttons, and both the Solo and Dim signal levels are adjustable. The monitor volume control is set with a nicely oversized knob, and the output can be routed to either Main or 'Alt' speaker destinations (the latter with a separate ±10dB trim control). Both are presented on rear-panel XLRs.

The console's headphone amplifier — which proved plenty loud enough on a pair of 300Ω Sennheiser HD650 headphones — has two paralleled TRS output sockets, one under the front arm rest and a second on the rear panel. The headphone signal is derived from just before the monitor section's volume control (so post the source, PFL/AFL, mono and dim selections), and has its own independent volume control. Two more push-buttons turn the headphone output on/off and replace the monitor section signal with the Cue mix output instead.

The final element of the master and monitor section controls the talkback facilities. The gain of the built-in mic can be adjusted and routed to the slate (program mix bus), aux (all four) and Cue destinations, with a momentary press-to-talk button to activate the talkback (and dim the speakers to improve intelligibility). Recessed trimmers in the top panel allow the relative levels of each destination to be tweaked, if necessary.

The rear panel of the console in full. Note the hinges, which allow for easy service access.The rear panel of the console in full. Note the hinges, which allow for easy service access.


After using The Box for a day, and becoming familiar with its ergonomics and features, I have to say I have become a fan. This is a great-sounding console, which is easy to use and has many genuinely useful facilities that are rare to find on a physically compact desk. API have retained the big-console feel here in terms of operating features and ergonomics, as well as sound quality and connectivity.

Really, the only negative comment I would have made is that the review console ran surprisingly warm. However, API subsequently discovered that the power supply was defective, and have now replaced this.

The Box console has an unusual feature set, quite unlike any other console I'm aware of and, consequently, is likely to be a 'Marmite' product — something people either love or loathe. Some will think just four input channels is inadequate, or dismiss the console for its total lack of DAW remote control or automation facilities. Others will argue that the cost is too high and that better solutions can be constructed from separate units for less.

All of these arguments have some validity, of course, and The Box certainly won't satisfy everyone. However, it's an extremely well thought-out console, it has remarkably versatile connectivity and internal signal routing, and it is a proper, fully specified, fully integrated, high-end console with all the features, performance and convenience we associate with that claim.

For anyone who likes to work in a traditional, console-based way, who only needs to record a maximum of four sources at once (or six with a bit of creative patching and some additional preamp modules), and who likes to mix in the analogue domain, The Box is a very elegant solution. Its cost is reflected fairly in its quality, versatility and performance, but this desk is a delight to use, it looks the business and, most importantly, it sounds utterly fabulous.


The UK retail price for The Box places it in the same ballpark as the 12-channel version of Audient's ASP8024, while it is slightly more expensive than their 4816, and slightly more affordable than SSL's Matrix. However, these all offer radically different feature sets to The Box and don't employ transformers in the signal path. The Harrison 950m is arguably more comparable, but is slightly more expensive, reflecting the greater number of tracking channels.

Interestingly, constructing something similar to The Box using 500-series modules (10-slot rack, 4x512C Preamps, 4x505 DI, 2x550 EQs, 2x527 compressors, and two 8200 eight-channel line mixers) would cost around $16,000nearly £13,000 — and you'd still lack a monitor controller, aux and cue send facilities, and faders. In that context The Box doesn't seem quite so expensive after all.


Electronics technology developed at a phenomenal rate after the Second World War, and the 'operational amplifier' (op-amp) — which was first conceived for analogue computers during the war — became a popular general-purpose circuit block. An op-amp is essentially a DC-coupled, high-gain voltage amplifier with a differential input and a single-ended output — and it makes a very handy and versatile 'gain stage' for audio systems.

The first commercially available op-amps appeared in the early 1950s, made by a company called George A Philbrick Researches in America. The GAP/R K2W comprised two 12AX7 valves (tubes) mounted in a bespoke housing, which contained all the necessary internal circuitry, with a standard octal base to access the power, input and output connections. Moving into the 1960s, when semiconductors became available, solid-state op-amps started to appear using discrete transistor circuitry, such as the GAP/R P45 and P65. The P45 is really the origin of the modern DOA or 'Discrete Op-amp', and comprised eight transistors, eighteen resistors, a couple of diodes, and six capacitors, all mounted closely together on a small printed circuit board roughly 1.5 inches square. The whole assembly was 'potted' to form a 'black brick' using a special resin to ensure thermal stability and to protect the design. Seven pins at the base provided the power and signal connections, and this arrangement has become the standard audio DOA format.

Through the 1970s various manufacturers developed their own DOAs specifically for high-performance audio applications, with carefully selected transistors optimised for different circuit elements, such as the differential input stage and the output driver section. The best-known audio DOAs are the Melcore 1731, the API 2520, and the Jensen 990, but although these all share the same basic concept they differ significantly in design detail and, consequently, sound character and technical performance.

While API chose to employ DOAs in its consoles, other contemporary console manufacturers, like Rupert Neve and Calrec, followed a different route. They also used individual, modular, discrete transistor gain stages — such as the Neve BA283, for example — but these were generally rather simpler and more traditional amplifier designs, typically with between three and six transistors, and they lacked the differential input of the DOA.

The op-amp concept is still very popular today, but is most commonly found now as a 'monolithic integrated circuit' or IC. The performance and quality of modern IC op-amps has evolved to a level that equals or exceeds the DOA for the majority of audio applications (although some would, no doubt, argue that point), but back in the 1970s the early monolithic ICs couldn't come anywhere near the performance of a good DOA. The sound character of the early API consoles — as well as all subsequent API discrete products — was (and is) directly attributable to the company's extensive use of their bespoke 2520 DOA design.

527 Compressor Module

Like the built-in 550A EQ modules on channels 1/2, the console's dual 527 compressor unit — located at the top of the centre section — is also a re-packaged version compared to a standard 527 rack module. However, the circuitry is mostly the same, with the only significant difference being the omission of an output make-up gain control. Instead, this version of the 527 has an automatic gain make-up system, similar to that employed in the 525 compressor.

Like the stock API 527 (which I reviewed in the SOS October 2010 issue), the version here is configurable with the side-chain working either in a feed-back (old-school) or feed-forward (more modern) arrangement, with a switchable hard- or soft-knee characteristic and API's unique 'Thrust' mode. This last feature high-pass filters (roughly 3dB/octave below 1kHz) the side-chain control signal to reduce the compressor's sensitivity to high-energy, low-frequency elements in the programme. When enabled, the Thrust mode helps to maintain a powerful bass end, while still controlling the overall dynamics through the mid range and HF.

The two 527 channels can be used independently, or linked for stereo applications (the controls of both sections need to be matched for consistent operation), and each section has its own gain-reduction meter. Rotary controls are provided for threshold, ratio, attack and release, with buttons for in/out, hard/soft knee, old/new side-chain configuration, and Thrust mode. In addition, each section has two more buttons to determine where the compressor is connected in the console. The first button selects the stereo program mix bus or input channel, and the second determines which channel — the top section can be inserted in channel 1 or 3, and the lower one in channel 2 or 4.

In use, these compressors impress just as the stock 527 does. On the mix bus it can be incredibly smooth and transparent — especially in the soft-knee mode — even when applying substantial amounts of gain reduction. The scaling of the ratio control makes it just as easy to find very gentle settings below 1.5:1 as heavy limiting over 20:1, and the threshold spans a huge range from +10 to -20 dBu. If I had to be picky, maybe the release time could have a faster minimum setting — 0.3 seconds is a bit lazy in some contexts — and this is the major factor in why this compressor sounds very polite most of the time.

Second Opinion

I was intrigued by API's The Box. On the one hand, while in no sense of the word could it be described as 'cheap', it is by quite some distance the most affordable API console ever to be brought to market. On the other, a significant portion of the API reputation has been built on the use of their consoles to track rock bands, complete with multi-miked guitars and drums — and unless you're deeply into lateral thinking, The Box just doesn't offer sufficient mic inputs to make that sort of work easy.

With these points in mind, I was initially quite prepared to dismiss The Box as an overpriced or under-specified hybrid. Yet, like Hugh, over the course of a day tracking and mixing a band via this console, I grew to really enjoy using it. It looks good, it's well thought-out and well built, and it feels nice in use. The only real operational quirk not discussed already by Hugh was that I found it rather difficult to remove some 500-series modules, as the slots are slightly recessed, making it hard to get fingers or nails around the faceplates.

I'm not an advocate of analogue summing for its own sake — there's absolutely nothing wrong with summing in the digital domain, and I've usually been able to achieve whatever 'analogue warmth' I require by running the stereo mix through analogue stages. But I sense that this is not at all what The Box is about: the fact that the DAW return inputs feature balanced insert sockets suggests that it is intended as a centrepiece for anyone already running an analogue/digital hybrid mixing system, making use of both DAW software and a number of outboard devices. And in such a studio I could see this being a very useful device indeed.

As for the tracking side of things, the target audience is obviously those project studios in which the modus operandi is overdubbing: there are sufficient inputs to cater for dual-mic setups on a couple of sources simultaneously. But there is potential for more ambitious projects too. The aforementioned lateral thinking that makes it possible to use this mixer for close-mic drum tracking and other such applications is that you could conceivably invest in a rack of outboard preamps (one 10-slot and one six-slot API Lunchbox, perhaps?), patch those into the 16 summing channels and use the balanced insert sends to feed your recording device. You'd still get the benefit of the aux sends and true zero-latency artist monitoring that way, and have a total of 20 channels, each with the useful SIP and solo-defeat options that Hugh has described in the main review. Of course, that would require either a suitably wired patchbay or that you sacrifice using the console for analogue summing from the DAW... but it's worth knowing that this can be done.

I suppose I'm slightly less convinced than Hugh by the price. It has to be said that I could acquire a very decent recently refurbished second-hand console with many more channels featuring preamps and EQ for the asking price, though admittedly that ignores the potential for far higher maintenance costs. However, I would be very hard pushed to purchase something so heavily featured or versatile, and with this small a footprint, for the same money. Of course, some will argue that much of the price is in the brand name, but the flip side of that argument is that well-maintained API gear remains desirable and therefore retains much of its value. Add to this the warranty and number of years of reliable service it's likely to give and the price seems rather more justifiable. I just wish I could afford it... Matt Houghton


  • API sound quality thanks to its use of classic 2520 DOA circuitry and loads of output transformers.
  • Fully balanced I/O, with versatile connectivity options.
  • User-customisation via 500-series slots on channels 3/4.
  • Four API recording channels, with instrument inputs and access to aux and artist Cue buses.
  • Up to 22 (or 28) inputs on mixdown.
  • Full monitor section with talkback.


  • With an API badge, it was always going to be pricey...


API's The Box console has an unusual feature set, and consequently will appeal to a very specific subset of project studios — mostly old-school traditionalists who like to work on a 'big console', but don't need the overabundance of channels provided in most standard consoles. The Box is a 'big console' in terms of features, technology, connectivity, build quality and sound, but with sensibly restricted input and mix channel counts.


£14,999 including VAT.

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