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SILICON SILIC CHIP www.siliconchip.com.au Publisher & Editor-in-Chief Leo Simpson, B.Bus., FAICD Production Manager Greg Swain, B.Sc. (Hons.) Technical Editor John Clarke, B.E.(Elec.) Technical Staff Ross Tester Jim Rowe, B.A., B.Sc Nicholas Vinen Photography Ross Tester Reader Services Ann Morris Advertising Enquiries Glyn Smith Phone (02) 9939 3295 Mobile 0431 792 293 glyn<at>siliconchip.com.au Regular Contributors Brendan Akhurst Rodney Champness, VK3UG Kevin Poulter Stan Swan Dave Thompson SILICON CHIP is published 12 times a year by Silicon Chip Publications Pty Ltd. ACN 003 205 490. ABN 49 003 205 490. All material is copyright ©. No part of this publication may be reproduced without the written consent of the publisher. Printing: Hannanprint, Noble Park, Victoria. Distribution: Network Distribution Company. Subscription rates: $97.50 per year in Australia. For overseas rates, see the order form in this issue. Editorial office: Unit 1, 234 Harbord Rd, Brookvale, NSW 2100. Postal address: PO Box 139, Collaroy Beach, NSW 2097. Phone (02) 9939 3295. Fax (02) 9939 2648. E-mail: silicon<at>siliconchip.com.au ISSN 1030-2662 Recommended and maximum price only. 2  Silicon Chip Publisher’s Letter What next for hifi enthusiasts? Late last year, I visited the Sydney Hifi Show with one of our contributors, Allan Linton-Smith, who has written the report in this issue. I must say I was staggered at the stratospheric asking prices for some of the exotic gear on show. “Yes Sir, we can let you have a pair of these fantabulous loudspeakers for a mere $100,000 and that is a special price just for the Sydney show!” Well naturally I had real problems controlling the urge to splash out and buy. Ah, actually that’s a fib. I did not. I wonder how much of this exotic gear was actually sold at the show. Another interesting aspect was the number of valve amplifiers on display. Now you might have heard of “cricket tragics”, those people who keenly follow the Australian cricket team no matter how dire their performance. Well, it seems that there were a significant number of “valve tragics” at the Hifi Show as well, going into raptures over the “sound” of these masterpieces. These poor deluded souls really do believe that valves are wonderful; much better than those despised solidstate amplifiers with their vanishingly low distortion. What piffle. Even if it was true that valve amplifiers are superior, you would be hard-pressed to make any objective judgment about the sound quality of the loudspeakers and the driving amplifiers in typical small hotel rooms – which is where most of the exhibits were. Unfortunately, that is the drawback of most hifi shows; inevitably, exhibitors demonstrate their gear in hotel rooms. Having said that, there were some exhibits which did sound pretty impressive and that was particularly the case where the program material was carefully selected, the volume was not at deafening levels and the room had only a few people, seated in an optimum listening position. Also at the show were a number of high-end high definition video projectors. They really were impressive and I would have liked to spend a lot more time watching them – if only the sound had not been wound up to pain levels. There were a significant number of turntables on display too, as further evidence that vinyl recordings are going through something of a revival. It must be admitted that there is something quite satisfying about a playing a record. No, you don’t press a button to select a track; it is a truly manual process as you position the stylus over the start of the track and carefully lower it onto the record. CDs have taken away that ritual. For me, the JBL S-4700 3-way system with a 15-inch woofer, horn midrange and horn tweeter was an ear-opener. It was quite efficient for a hifi speaker and was driven by a relatively low-powered amplifier. Again, you can’t really make a fair assessment in a small hotel room but it was impressive nonetheless and from a cabinet which was not overly large at just over a metre tall. This is really a throw-back to the past and quite a different approach from current tower-style speakers with relatively small diameter drivers of average or low efficiency. With such a large cone area, a 15-inch speaker does not have to work very hard to produce copious amounts of bass. It got me wondering what we could possibly achieve with a do-it-yourself highefficiency 15-inch woofer. It should not be difficult to get a flat response down to around 25Hz or so. In fact, it should relatively easy. It could be a real room-shaker. And with high efficiency, it could be a very good match with our 20W Class-A amplifier. For even more grunt, our Ultra-LD amplifier could drive such a speaker to truly deafening levels, even in large lounge rooms. Even a valve amplifier could probably do a reasonable job of driving it. OK, that was probably a bit patronising but there is an element of truth to it. If a valve amplifier is not driven hard, it will generally have lower distortion, although nowhere nearly as low as from a well-designed solid-state unit. Leo Simpson siliconchip.com.au