EQUIPMENT REVIEW

The Heed Audio Modular Amplification System

by Paul Messenger

I like minimalism. I fondly recall the Naim NAC12 pre-amp that I acquired in the mid-1970s and used for more than a decade. It had three knobs, no switches, and just three inputs (which was all that one needed in those days: one for vinyl one for tuner and one for tape). Friends at the time marveled that I didnt mind sacrificing tone controls, scratch filters, loudness contours and so forth, and I admit I was initially apprehensive that Id miss all the extras. But I didnt, and soon came to appreciate the more subtle advantages of utter simplicity. Its an attitude that continues to this day, and is one reason why I can raise little enthusiasm for devices such as VCRs, computers and mobile phones, all of which seem to regard complexity as a virtue, if not an end in itself. The worst offenders are computers of course, which are veritable chameleons in their complexity, and their pernicious influence is spreading inexorably into our hi-fi components. High-class pre-amps Ive used recently, such as the Naim NAC 552 and Halcro DM10, are essentially computers at heart. They offer extra flexibility, true, but do so at the expense of simple intuitive operation, requiring that the manual is kept handy for ready reference. At heart therefore, I much prefer products that are simple and unambiguous in operation, and thats reason enough for a close up look at this very neat and ultracompact amplifier combo, which is unusual for several reasons, not least that it comes from a Hungarian manufacturer called Heed Audio. Few can beat its minimalism, yet it does have some useful flexibility at the same time, partly through its modular architecture. Each part is built into a tiny little rectangular steel tube, just 7cm high, 9cm wide and roughly stage called Quasar (550). And theres the additional upgrade option of doubling up the power amps in order to bi-amp the speakers. The Luna has just a single knob alongside a single pushbutton, so ease of use is clearly exceptionally good, assuming that the availability of only two inputs is not considered a fatal handicap. A further ergonomic bonus is that the volume knob is motorised, and may be operated by remote control; input selection, however, is exclusively hands-on. Before getting any deeper into the product, a little more background is due, since Heed Audio is very new to Britain. The two principals, Zsolt Huszti and his brother Alpar, started out importing a number of leading British brands to Hungary in the 1980s. They developed a particular relationship with Richard Hay, at one point actually assembling the Ion Systems Obelisk amp in Hungary. Zsolt has subsequently applied some of the same underlying technical principles in his own electronics designs, including using balanced circuitry, outboard power supplies and the deliberate avoidance of DC coupling. The first of these little modular units appeared in 2000. An outboard power supply for Rega Planar turntables, its codenamed Orbit, sold particularly well in Germany, and will be covered elsewhere in Hi-Fi+. The two-box Quasar phono-
27cm deep, with a front panel in Perspex decorated by a blue LED dead centre. Its a bit hair-shirt in appearance and feel, and the steel-wrap casework doesnt quite have the appeal of the alloy extrusions used by Crimson and Creek, for example. But its neat, beautifully discreet, and entirely practical, apart perhaps from the need for a considerable number of mains leads! The system can be configured in several ways, the core collection covered here comprising a two-box Luna pre-amp at 550, and a pair of Canopus mono power amps (550/pair). Then theres a single-box MM-type phono-stage called Pulsar (275), or a two-box MM/MC phono-
stage then followed, enjoying similar success and leading on naturally enough to variations like the Luna two-box pre-amp and Canopus mono power amp that are the main subject of this review. Although the Luna pre-amp is simple to the point of simplistic,
mentary 25amp power transistors. Fully balanced circuit topology reduces susceptibility to external interference. An extra phono socket is fitted to pass the input signal onto a second power amp for bi-amping.
with just two stereo inputs plus two stereo outputs (one fixed the other variable) the Quasar phono-stage offers a comprehensive array of loading and gain options. Its a dual-mono design with separate amplifier stages for MM and MC cartridges, the latter effecting adjustments of sensitivity and load via PCB jumpers. Separate high and low outputs are available, the former specifically for driving power amps directly. The Pulsar, for high output (MM) cartridges only, follows a broadly similar configuration. It uses passive/active RIAA equalisation, and has ample output for direct power amp drive (via a passive pot). The 50W Canopus power amp is a three-stage Class AB design using fully discrete components. Its power supply has a 100 VA toroidal transformer and two 10,000 F capacitors, while the Darlington output stage has comple-

I started off simply plugging my regular Naim pre-amp into a pair of Canopi, with results that were a little dull and disappointing. This was clearly not an ideal match, so I added the Luna pre-amp to the equation, which perked things up considerably. Fed from a top quality CD player, a Burmester 001 as it happens, the Luna/Canopus combo immediately impressed with its lovely delicate and expressive mid-band. Singers inparticular sounded very believable, especially when they were well towards the front of the mix, like Alison Krauss on the Alison Krauss + Union Station Live CD, where
she managed to sound even more seductive, humorous and simply more human and real than usual. At the same time, the top end is rather restrained, which can often be beneficial with modestly priced equipment, but which also manages to suppress a little fine detail. Id just acquired and was exploring Lambchops new double CDs, Awcmon and Noyoucmon, which is a much denser production than its predecessor Is a Woman, and has Kurt Wagners lead vocal much further back in the overall mix. I was finding it difficult to pick up on the lyrics, because the consonants were a little too retrained. Changing back to my regular (much more costly) amplifier did improve the diction, and make it easier to make out the lyrics, confirming that the little Heed amplifiers do have their limitations. But then youre not going to
achieve amplifier perfection for 1,100, and what this cute little combo does well, it does very well indeed. Theres little evidence here of the mid-band congestion and thickening that is found in many amplifiers, especially those built from solid state components. And while I wouldnt describe the Luna/ Canopus as thermionic in character, it clearly manages to avoid many of the solid state vices. Partly to check out the bass end of things, I hooked up some monstrously large Tannoy Yorkminsters, a 100-litre reflex-ported enclosure with a 12-inch
are quite expressive, if a little soft and lacking in tension. Decent levels of loudness could be achieved, even with relatively insensitive speakers like the Leema Xens. That said, I did generally prefer the sound of this amplifier when it wasnt working too hard, as a mild presence emphasis seemed to become more obvious and show a touch of aggression when it was sweating. Checking out the vinyl stages showed that both the Quasar and Pulsar had broadly similar characters to the Luna/Canopus combo, and that the two-boxer is clearly superior to the single-box Pulsar in terms of dynamic authority and precision. Both slightly roll off the extreme top end
way this Heed combo transcends mere issues of sound quality and simply gets you into the spirit and emotion of the music itself.
T E C H NI C AL S P E C I F I C AT I O NS
Canopus Type: Input Sensitivity: Impedance: Power Output: Mono Power Amplifier 500 mV 10 kOhms 35 W/8 Ohms 50 W/4 Ohms Bandwidth (with filter): 4 Hz-60 kHz (1 dB) Price: 550/pair Luna Type: Inputs: Outputs: Remote control: Price: Quasar Type:

Stereo pre-amplifier with separate power supply 2x line 1x line, 1x variable Volume only 550
Phono-stage with separate power supply
Sensitivity MM input: 5 mV /47 kOhm / 100 pF MC input (adjustable):100 V / 200 V / 600 V MC Input Impedance:100 Ohm / 220 Ohm / 470 Ohm Output voltage "Low Out": 220 mV/100 Ohm Output voltage "High Out": 775 mV/ 22 Ohm Price: 550 Pulsar Type: Input Sensitivity: Input Impedance: Bandwidth: Output Level: Output Impedance: Signal/Noise Ratio: Price:
Alnico magnet Dual Concentric, and was impressed at how clean and firm the bottom end sounded here, even without embracing the DC-coupling that so many other designers advocate. The tiny Canopus has convincing enough weight, but might perhaps have had a bit more drive and urgency. The mid-band in particular possesses good transparency and depth resolution, and the sound as a whole is notably free from any shut in boxiness. The dynamic range is good, and dynamics themselves
MM Phonostage 5 mV 47 kOhms 20 Hz - 15 kHz/ 0,5 dB 600 mV 50 Ohm 80 dB 275
and soften leading edges just a little, but have notably coherent tonal and dynamic structure and architecture. I was spinning a familiar favourite, the Grateful Deads acoustic Reckoning set, and found myself sucked into focusing on Garcias guitar much more intently than usual, and my partner actually started dancing along as she came into the room. Which rather neatly sums up the
Physical Specifications (all): Dimensions (WxHxD): 90x 70x270mm Finishes: Black casework with either black or white fronts. UK Distributor: t-Source Tel. (44)(0)E-mail. heed@tsource.co.ul Manufacturer: Net. www.heedaudio.com

Integrated Amplifier Heed Obelisk Si Previously unknown in France, Heed is entering our territory. The brand was founded by two Hungarian brothers named Huszti, who had been passionate importers of renowned English marks including Nytech and Ion Systems, as created by Richard Hay. From the beginning, they demonstrated an enthusiasm for the kind of high-quality discrete circuitry that in this day and age seems almost quaintly relegated to the past. Their philosophy draws undoubtedly on the innovative talents and unconventional know-how of Richard Hay since the three men continue to collaborate closely. So the resurrection of the Obelisk name here, of course, appropriately reflects its predecessors distinguished heritage. Heed also perpetuate its original modular design concept; separate components, offering additional levels of performance, etc. The compact size of the Si has something attractive, elegant and perfectly formed about it; even more so in association with its optional power supply of like dimension, the X-2, also strongly recommended. The circuit design and execution demonstrates originality: the designers have sought to obtain, and (for once) have succeeded, in presenting "a sound which approaches that of the tube" exhibiting the same nuance, the same distinct signature. Two substantial knobs on the facade are responsible respectively for source selection and volume control. The Obelisk employs two Darlington transistor pairs per channel, operating in push-pull. Manufacture and buildquality is in the finest English tradition. Power & Finesse It is a rare occurrence indeed that a component under review sets itself so far apart from the pack. Is this the fruit, for the time being, of a real musical culture claimed in this case, by the Hungarian? It can never be stressed enough that the development of the best products cannot be achieved without aesthetic purpose, and furthermore, without subordination to the music. This explains the preeminence of English devices and perhaps only a certain very few models from our part of Europe. From the first note, we are stunned by its silken quality, particularly noticeable on the strings that suddenly begin to breathe naturally. By comparing the Obelisk to our dear Etalon ("Diapason D' Or" award winner; of Hungarian origin also) we clearly prefer the Obelisk. It is unquestionably more refined, while preserving the indispensable freshness and undeniable
wealth of those aspects that comprise the charm of the Etalon. Its frequency response glides along on the edge of perfection, demonstrating impeccable harmony throughout the spectrum. The Obelisk deftly negotiates dense passages with aplomb, yet is always accompanied by finesse and simplicity, indeed, consider the best tube amps. It is much closer to the "live" magic of a reference-quality 300B than it really has any right to. Stereo imaging is resolutely three-dimensional, wonderfully spatial, all the while delivering an absolutely precise rendering of source material. Its character satisfies fully, providing the highest resolution imaginable, but without the slightest hint of artificial brightness. Finally, the Sis dynamic range approximates the spontaneity we hear attending a live performance, evoking the very same impression. A genuine revelation at a price, after all, without competition. Characteristics Type: integrated amplifier Power: 2 x 42 watts Remote control: no (at time of review, but forthcoming) Phono stage: optional Headphone out: no Origin: Hungary Prices: Summary Musicality Frequency balance Fidelity Sound quality Refinement Transparency Dynamics Soundstage Build quality Heed Obelisk Si Heed Obelisk X-750

Strengths: Finesse and exceptional silkiness. Remarkably beautiful musicality. Weaknesses: Hardly any.
DIAPASON, July-August 2008