September 2007

Living Off The Grid, By Choice
A careful look at Apple's iPod, NAD's PP1 phonostage, and the amazing Sonic Impact Super T amplifier.
Article By Jeff Rabin

The phrase living 'Off the Grid' will forever raise a lump in my throat. Not a good lump though, such as you might experience on seeing watching a baby giraffe dropped from 6 feet during birth, or a penguin having swallowed whole a particularly succulent Artic Char, but the kind of lump that comes as a result of gagging on a chicken bone.

My difficulty at swallowing this loaded phrase is (autobiographically speaking) perhaps not that surprising. While I do recycle newspapers and dutifully return my empties for the return of my paltry deposit – it's the principal, you see. I drive a 5 litre gas guzzler, fly across the Atlantic on a regular basis, like my bath filled to the brim, do not keep compost, and like my air-conditioning during this weird humid summer.

So what in Lee De Forest's Audion's name am I talking about? Inarguable hi-fi fun, as something in hi-fi is often sadly lacking.

While dropping out of the Internet matrix has its undoubted appeal, what of dropping off the AC drip entirely, I wondered. Absent myself from the Nuclear, hydro-electric, coal burning complex, burn renewable forests grown on my own land for heat, raise tubers, make jam, bicycle, slaughter my own hand raised lambs, knit sweaters, eat beans, produce my own nature gas, and cook over an open fire. A rustic idyll for some, but not for me. Modernity may have brought its share of ills, but I will take clean drinking water over burning dung for heat any day. I also believe the witches in Salem got a raw deal.

Returning to a state of nature, carbon credits notwithstanding, is not what I mean. The creature comforts of the twentieth century have, to me, become more than comforts.

So What Am I Talking About?

I am talking about getting off the alternating current grid, alternating current of course anathema to those of us who will go to almost, maybe I should delete almost, any lengths for good sound. And what better way to eschew the nasties of the wall socket than to forsake it altogether?

Sure, I could either pick up an instrument or attend live unamplified music, but doing so would be giving up more than I am prepared to do. Leave my couch?!? These are supplements, not replacements, like tonic in gin. A crystal radio set? Hardly hi-fi, but well worthwhile building one. What, however, of running everything off batteries? Amplifier, source.... and loudspeakers that don't ask for wall power?

Of course I could tote a boom box but am not a fan of all in one shoulder mounted systems. Plus, I might be tempted to leave my living room and beloved couch. Then, in a veritable coup de foudre, Apple's penny dropped.

Why not run my recently acquired Super T-AMP off an old car battery, driven by an Apple iPod also on batteries (sadly captive), into my beloved Tannoy D700s? The fine fellows at Sonic Impact had even included a suitable power lead. A preamplifier, battery driven or otherwise, would be unnecessary as both the T and Pod have their own volume controls. I used the T's. What's more, I had all the gear on hand. One messy sitting room later and I was in mains-free biz.

(On a not unrelated note, I would gladly wager money against our esteemed editor's Antique Sound Lab Wave 8 budget killer in issue August 2001 for sound, though that thermionic glow ASL's Waves glow does takes some beating.)

Editor's note, Steve sez, "Am sure the system sounded quite nice! Have personally reviewed an off the grid systems with impressive results. Read my Final Labs reviews as seen here. On another note, and due to my experience with major car audio competition/systems, that car battery you used could be supplemented with a grouping of about eight small power capacitors for filtering and whatnot.

Power conditioning, with all its assorted costs and jiggery electrical pokery, my ass. What we're talking here is pure DC as God, but not as Edison intended. Of course, from the wind-up gramophone to the wonderfully eccentric Final Labs, I would not be the first, but here is something I could do with my existing kit without changing sides every three and a half minutes.

The Line Up

Click wheel iPod loaded and charged to the gill with music in lossless format. (You could also use a portable CD player or radio.) Cheap mini to RCA stereo cable 'borrowed' from my wife's PC. As a professional photographer, it will take her some time to miss it. Sonic Impact Super T Amp 'borrowed' from my son's PC. (It's OK, I traded him a Rotel 820XB2 and he's in the UK at the moment). Layabout, thankfully terminated, cables and a pair of Tannoy D700s that I know well. This is more than required, but were conveniently placed in the sitting room and are bastards to move.

Any decently sensitive loudspeakers (the Tannoys on paper at least are 93dB at 8 Ohms efficient with a less than benign load) I would imagine would do. In this system, I feel the speakers are the weak link as is often the case. A pair of wildly sensitive horns would have shown – warts and all – this battery powered system to even greater effect.

Power was supplied both by charging up the iPod – which seems to consume much more power with lossless files than with compressed ones – and an old OEM BMW car battery that I had laying around the basement from last winter charged by an old Canadian Tire branded trickle charger that has saved my bacon on more than one wintry occasion.

After a night's charging, the system would run as long as I listened until reconnecting the trickle charger. The trickle charger has a small meter on it showing the state of the battery and after the first charge I never saw it dip before full, not surprising really when you think of just how efficient these so called 'Class D' amps really are.

I even engaged in a bit of tweakery. I laid the Sonic-T on its side (I think it looks better that way with the blue LED taped over. In any event, can now read without a blue spot hovering on the page on top of a Cambridge Isolation Platform. The iPod was placed on a beanbag on top of the platter of my well-damped Garrard 301.

In a blatant betrayal of this article's modus operandi, I also tried the system with a number of electrically tethered sources, including the aforementioned Garrard 301 wearing a Rega RB350 and an almost as rare as hen's teeth high output NAD 9001 moving coil brought to line level by an Ear Yoshino 834p and an elderly Carver tuner with about the best AM section I have ever met. I do like coast-to-coast AM with Art Bell, thank you very much. All sounded great, though the Carver showed on AM a high-pitched whistle that I don't remember hearing before. Keeping to this assignment's remit, also used a Sony 7600 battery powered world band radio and could use – but this would require both an outing and expense to my hated local Ratshack – a DC powered NAD PP1 phono stage.

So how did my mains free experiment in hi fi foolery sound? Well, not to toot my acoustic horn, amazingly well. This battery-powered system is not one to fill an arena or do proper justice to the 1812 symphony, but it was eminently, fantastically even and very listenable. It was a system whose faults were more those of omission than commission. While kick drums did not kick, I don't doubt those whose taste runs to single-ended triodes would be more than a little embarrassed in front of their bank managers.

Midrange was glorious with perhaps a touch of sterility that I feel might have less to do with what the Amp subtracted and more to what other amps add. Inner detailed beggared belief. Treble easily exceeded what the iPod had to deliver, again without grain or glare. Bass, unsurprisingly, was a let down. Never did I feel a punch to the gut or that feeling of my room loading in the way a Church does even before the organist starts playing but after he has set himself down at the controls and not merely because of their unusually fulsome girth. Nonetheless, if light, bass was tuneful. I would suggest that a more appropriate set of speakers, with an easier, would mitigate this meager gripe.

What was perhaps most remarkable was a complete absence of listener fatigue that I normally only associate with valve amplifiers. But here, however, conspicuously absent, was that sense, if not always an auditory cue you can put your sonic finger on, that you were listening to valves. Moreover, I did not have that sickening feeling that every minute I listened was one less minute in the lives of the valves or that nagging question which almost never leaves my mind as to whether a valve was past its last legs without my noticing, so gradually and amenably do most valves fade away.

Indeed, this was a system without mods – and of gear laying around the house – that I could happily and uncritically listen to day and day out. And while I suffer from a serious case of hi-fi disease, rarely having the patience to leave well enough alone, I plan on keeping this in situ – perhaps with my home made Bert Doppenberg design Tapered Quarter Wave Pipes – for a good time yet. What's more, I should gain some green cred with my tree hugging acquaintances, friends, however, being too good a word for them.

Hi-fi should, as I have often written in these pages, be in large part fun – and there is no shortage in this world of more serious matters – but this experience 'off the grid' was as much fun in hi-fi as I have had in a long time. If you do not already have a cheap and cheerful digital amp such as the T-AMP, they are cheap as chips on Epay. I know you either have an iPod, it's ilk or a portable radio that can be put to use. You can cut corners by using a power sucking source. Without reservation I recommend this experiment and doubt you will throw out the Krell with the bath water, though I guarantee you will raise yourself a smile.