Malcolm Steward: audio journalist

This article first appeared in Hi-Fi Review May, 1989

Arcam Delta Black Box 2

So what’s this? Is that the Editor dirtying his hands with something digital? Isn’t that kind of business normally left to Noel Keywood? So what’s Steward doing with this Black Box gizmo? Surely that’s something you connect to… a CD player? He’s never gone over to CD has’ he?

The answers to all these questions and more now follow: I) What’s what? 2) Could be. 3) Yes. 4) You’re just about to find out. 5) Yes, it is now you come to mention it. 6) Do me a favour.

Why I’m currently in possession of the Arcam Delta Black Box 2 Digital to Analogue
Convertor with optical input, dress it in its full titular regalia, is because I asked  John Dawson, A&R’s boss, if he would let me borrow one. Recognising me as the honorable, trustworthy gentleperson that I am he said that I could. What also might have helped was the fact that he had just demonstrated it to me at the Bristol Hi-Fi Show and I had been unable to conceal my surprise at the improvement it had wrought upon the compact disc he was play­ing.

Before you get carried away and start draw­ing all sorts of erroneous conclusions let me state that in no way am I about to forsake my LP collection and become a convert to the sil­ver disc. But since getting the £299.90 Black Box 2 installed at home, I have to admit that CD listening has become a lot more pleasur­able or a lot less irritating — choose whichever expression you prefer. CD still doesn’t get my sap rising the way an LP does but it doesn’t have me reaching immediately for the mute button the way it used to.

So what is this wondrous device? In essence, the Black Box 2 is an add-on Digital to Analogue converter that can be used with any standard CO player fitted with a digital out­put socket which conforms to the ‘Red Book’ Philips/Sony format. Unlike its predecessor — the original Black Box (which can be upgraded to ’2′ spec tor £50) — it also has provision for a TOSLINK optical input, now that many more CD players feature such an output — and if you are silly enough to duplicate your connec­tions and hook up both optical and co-axial inputs the Black Box 2 automatically switches itself to receive the optical signal. A&R contend that an optical connection is preferable bec­ause it is less prone to RF interference than a conventional electrical link, and when there is no electrical connection between the CD player and the DAC there is no path for noise and rubbish from the former to get to the latter. Not having a suitable CD player to hand I wasn’t able to hear this for myself.

The basic ideas behind their separate DAC are that by building a stand-alone unit A&R can physically remove the signal processing cir­cuitry from the hostile environment that is afforded by conventional CD players (Arcam will soon be releasing a player that only con­tains the transport mechanism and circuitry — an ideal partner for the Black Box 2). When iso­lated the signal processing circuitry no longer suffers interference from transport mechan­isms, control circuitry, display and logic circuits etc. It is also possible to power the DAC’s cir­cuits independently — in the Back Box 2 there are two mains transformers, one for the digital stages and one for the analogue stages, to minimise interaction between the two sides, and no fewer than seven regulated DC power supplies. Arcam has also reduced the num­ber of ICs in the circuitry by use of their own, and I quote unique British-built custom ASIC which to the likes of you and me means an appli­cation specific integrated circuit which demod­ulates the 44.1kHz digital output taken raw from the CD or CD Video source. There is also the in-built facility for decoding the 48kHz data stream from a DAT player. As yet there is no provision for 32kHz DBS (Direct Broadcasting by Satellite) applications but I’m sure A&R isn’t unaware of that as a possible source for its future attentions. In the analogue section no integrated circuits whatsoever are used — everything in that part of the signal path passes through good old discrete transistors.

But, before I dig myself any deeper into a technical trench from which I’m unable to climb out. let’s look at the more practical side of the Black Box 2. The device is aimed primarily at the owners of modest CD players who wish to upgrade the performance ot their machines without  having to junk them arid start again from scratch by buying a more expensive player. Owners of machines like the one currently resident at my house, the £250 Marantz CD65DX take note: this box was designed for you…

The Black Box 2 won’t delight the look-at-what-l’ve-just-bought type of purchaser. Blackpool illuminations or Concorde’s flight deck, it is not. Housed in a stylish but slim black case, the same sort of width and depth as most CD machinery, but only 64mm high, it doesn’t exactly draw lots of attention to itself. Its fascia is graced by two small push-buttons, each accompanied by a single LED display: one is power for on/off, and the second is for swopping the absolute phase of the signal (the LED glows green for ‘normal’ and red for ‘reversed’ — simple and neat). Around at the tradesman’s entrance not much more is stirring: there’s an EC socket for the mains connector, an optical input socket with blanking plug (a suitable interconnect is provided for use if applicable), an RCA phono socket for digital input (again an 075m interconnect is provided), a polarity switch (some machines will require this to be operated; the majority will not so most probably you can ignore it) and, finally, two sets of RCA phono sockets, which deliver the audio output your (pre-)amplifier. One set of outputs is at CD level (2V max, 500mV nominal) white the second is attenuated (800mV max, 200mV nominal). I preferred the sound of the ‘CD’ out­put and used that throughout my listening sessions.

I tried the Black Box through my regular home system (Naim amplification driving active SBL loudspeakers) partnering a Marantz CD65DX CD player, The CD player sits atop a Sound Factory Tripod stack and the Black Box was plonked unceremoniously on lop of its case This was expeditious as firstly it meant I didn’t have to add an extra level to the Tripod stack, and secondly the Black Box 2 nicely damped the rather resonant top panel of the CD65DX, which made for a much neater arrangement than the pile of paperback books that normally performs this task. Interconnects (CD player to preamp and Black Box 2 to preamp — two sets were required to perform A/B comparisons) were of the HFR 2phono-5DIN variety although John Dawson kindly provided two beefy-looking AudioQuest Livewire Quartz cables (£69), I promise to try them soon: 1 know they’ll come in useful — if by chance they don’t sound any good they certainly look tough enough and large enough to make a set of jump leads for the car.¹ Having switched on the CD65 and Black Box 2 and left them to warm up overnight — the rest of my electronics are never powered down — I began by listening to a varied selection of material to get an initial impression of what the Black Box 2 could do. It certainly seemed to improve the sound of the vast majority of discs I played through it, although the amount of improvement varied quite noticeably.

With some discs I found that the changes it brought about were immediately apparent; with others the effect was more sub­tle. But its performance was definitely consistent — there were changes evident whether they leapt out at you or whether they crept up on you after more careful or prolonged listen­ing. It was only after the session was over that I realised the most obvious benefit of using the Black Box 2: I looked at my watch and realised that I had just spent an unbroken period of hours listening to compact disc — not minutes, but hours. My ears weren’t ringing. I didn’t have a headache, and I still felt like listening to music. That alone, for me, was sufficient to war­rant a recommendation for the producl. But you’ll want to hear more of what the device offers so let’s get down to some specifics.

Joe Jackson has a voice that when repro­duced unsympathetically — as CD normally does — can drive me to distraction. His double CD Live 1980/86 had, prior to the arrival of the Black Box, seen little service in my house. The songs and performances were beyond criti­cism — it’s a truly fabulous live album — but whenever I wanted to hear them it had to be on vinyl. I still prefer the latter but with the Black Box 2 in circuit listening to the CD version became much more palatable. I chose the a cappella version of Is She Really Going Out With Him as a starting point. Without the Black Box 2 his voice was harsh arid extremely penetrating, the backing singers’ contributions were muddled and poorly separated, and the only instrument used, a tambourine, sounded most unlike itself, being all leading edge with no resolution of what happened after the initial strike. With the Black Box 2 doing its digital duty immediate improvements were noted before the song even began. In the intro to the number, noise from the stage and audience could be heard more clearly. Jackson’s voice, though still retaining its natural edginess, sounded fuller and richer, not artificially fleshed-out but., more natural. The backing vocalists were now better delineated, their voices having clear and separate identities, and were better distanced from the leading voice. Their harmonies were now clearer and easier to follow. And that irritating splash that had masqueraded as a tambourine now had more of the instrument’s true timbre and note-shape, the initial strike leading to an explosive transient, followed by audible decay and reverberation. Even the audience’s applause sounded more natural — like hands clapping rather than someone rustling silver paper.

The Special Delivery CD of Bobby King and Terry Evans Live And Let Live was next into the player. The track Just A Little Bit playing first. Once more there were improvements all round right from the opening bars. The drum-kit intro was imbued with more authority, kick drum having a greater sense of ‘heft’ and seemingly moving more air, while cymbals had more ‘sizzle’ and ambience. Terry Evans’ vocals lost any trace of the nasality they had before and again his voice sounded more dimensional, more solid. Ry Cooder’s slide guitar sounded harmonically fuller and its pitch more certain. Darryl Johnson’s bass was lifted from the depths of the mix and became more prominent. This was perhaps a contributory factor in the music’s rhythm picking up a shade, and the track sounding a wee bit crisper and more vigorous. So far, so good. But there has to be something of a down-side: if the Black Box 2 digs out more musical information it stands to reason that it will also dig out more garbage. The grunge before the start of track two on this CD proved this to be the case: it came through far more clearly with the Black Box 2 operating. That’s no bad thing of course — if something exists on the disc, you want to hear it, don’t you? Even if it does disabuse you alarmingly of the notion that CD backgrounds are absolutely silent. Sorry, but even if CD were perfect, microphones, tape recorders, mixing desks, musical instruments et cetera are not.

Londonbeat’s 9am (The Comfort Zone), another fine vocal offering was next up. Voices were again more sharply focused, more full-bodied and resonant, with an immediately apparent increase in detail. As I listened the Black Box 2 brought to my notice something that the CD player alone hadn’t: in places it appeared that the voices had been passed through a noise-gate in the studio; notes would start to decay naturally, then abruptly disap­pear altogether as though the microphone feed had been pulled. I offer no explanation for this but merely mention it to indicate how the Black Box 2 can draw such previously unnot­iced nuances to one’s attention. This record also features string overdubs which can sound rather astringent and steely through the CD65. Not so with the Black Box 2, so fans of the vio­lin on CD should investigate it in conjunction with their player if they suffer this problem. By far the biggest benefit, however, was the sense of warmth and atmosphere that the box gave to this rather dry recording, gracing the music with a more human touch than it pos­sessed through the CD player ‘straight’.

And so it continued. As I said at the begin­ning, not every improvement was as marked as the ones described here. Some discs even seemed unaffected by the presence of the Black Box, no obvious differences being apparent at the time. In these cases the Box’s contribution was later recognised as being subliminal: taking away much of the strain I normally experience with the medium.

What of the facility that I have yet to mention, the absolute phase reversal switch? I’ll be honest, after the first few times I tried it I forgot about it. Its effect on the discs I used it with were subtle to say the very least. To me it seems superfluous — who needs such a device? The only time I’ve otherwise seen them is on American pre-amps. Perhaps American ears are more sensitive to absolute phase than the British variety (no letters please, that was an attempt at irony). If phasing worries you that much you’ll already be practised at switching your speaker connections so you won’t really need a button to do it. Besides, as many have said before, it’s not absolute phase reversal that’s the problem, it’s the phase relationships of the various elements within a recording that’s more often screwed up. If you identify one out-of-phase instrument on a record, you’ll generally find that correcting for it puts other instruments out of phase instead. My advice: don’t lose any sleep over it. life’s too short.

Therefore, my conclusion about Arcam’s Black Box 2, based on my experience with it to date, is that it’s an extremely worthwhile device for those interested in upgrading their CD player to audition. It represents a genuine step forward in the reproduction of compact discs. I now wonder what the new A&R transport-only CD player will be like? Watch this space.