Professor M. J Hawksford (joint founder of LFD): Audio Amplifier Systems, A Compilation

This document is a compilation of technical papers relevant to both analogue and digital audio amplifiers and related systems. Topics include error correction, voltage-controlled amplifiers, current drive, current-to-voltage conversion and PWM. Emphasis is given to circuit techniques that include novel forms of distortion reduction. Audio Amplifier Systems, A Compilation (PDF Download Available). Available from: https://www.researchgate.net/publication/312557447_Audio_Amplifier_Systems_A_Compilation […]

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Professor M.J Hawksford (joint founder of LFD): Low-frequency sound source localization as a function of closed acoustic spaces

Further development of an emerging generalized theory of low-frequency sound localization in closed listening spaces is presented that aims to resolve the ambiguities inherent in previous research. The approach takes a robust set of equations based on source/listener location, reverberation time and room dimensions and tests them against a set of evaluation procedures to explore […]

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LFD AUDIO: Q/A with Dr. Bews – development speakers

Q: Dr. Bews. What speakers do you use during development? I use a pair of modified Celestion SL600 loudspeakers, rewired and the crossovers outside the box. These modifications helped immensely, to relieve the rather laid back, and slightly congested sound. Really I don’t think the absolute quality of the loudspeakers is that important when developing […]

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LFD AUDIO: Dr. Bews’ design philosophy

Hi Howard. You have ended up only selling LFD amps. What makes them so special and what is their design philosophy please. And no jargon please if you can. Thanks. Ralph. Dr. Bews reply: LFD Audio believe that audio Amplifiers can be most easily optimized if the basic amplifier topology is kept as simple as […]

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AUDIO RESEARCH: Meet Your Maker: Hi-Fi+ Visits Audio Research Corporation

Chris Martens: Reviews of products from the US-based firm Audio Research Corporation have frequently graced the pages of Hi-Fi+, so that I was pleased to have the opportunity to visit the ARC factory in Plymouth, Minnesota (a suburb of the greater Minneapolis metropolitan area) to see how the firm’s components are made. What follows is […]

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COLIN WONFOR: Q&A regarding their new HB100 mono power amps

HP: Gentlemen, you’ve been designing amps and preamps for over 30 years. Is it still a challenge and ….. are you having fun? A: Colin has been designing electronic professionally for over 40yrs. He has done this for a living. His many designs include power control and power supplies Linear, Resonate, Switch Mode and even […]

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So if less is more – and it is in audio – then how do we move away from these intrusive rolled sandwiches of goo, metal and plastic to couple our audio kit to the outside world?

Paul McGowan If we have a choice in our designs we’d prefer to have as little in the signal path as we can – the proverbial straight wire with gain would be ideal – but of course that’s just a myth. It’s been pointed out that perhaps this idea of minimal obstructions in the music’s […]

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TIM de PARAVICINI: King of Tubes is interviewed!

                    Stereophile write …… “How many hi-fi professionals can say that they’ve designed at least one of every part of a complete recording system, from microphones to tape recorders to vinyl-disc-cutting electronics? Probably only Tim de Paravicini (footnote 1). Best known to audiophiles for his extraordinarily […]

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SUMO: Audiophile interview with Rich May of Sumo; an audio dynasty

John Atkinson writes ………… Way back in the mists of time, around 1980 to be exact, the Marantz company in Europe introduces a range of ostensibly cost-no-object solid-state electronics under the “Esotec” banner. Manufactured in Japan, but apparently designed in the USA, these ruggedly constructed components are noteworthy in that the power amplifiers are capable […]

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Julian Vereker – THE interview

This piece was originally published in Stereophile in 1998: One of the big industry stories of 1985 was the split, both personal and commercial, between the British Linn and Naim companies. Led by Ivor Tiefenbrun and Julian Vereker (footnote 1) respectively, both companies had started up in the early 1970s. Both men held similar views, […]

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PIERRE LURNE: Design Philosophy For Turntables – a paper from Pierre Lurne Of Audiomeca

Enjoy The Music write ….. For those who are unfamiliar with his name, Pierre Lurne has been an integral part of cutting edge turntable design since the late 1960’s. Pierre designed his first arm design in 1968. He later was commissioned to do design work for a then major player in the audiophile turntable market. […]

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Nelson Pass – The Patents Of Pass

Brian Damkoroger: If high-end audio were to carve its own Mt. Rushmore, whose faces would appear there—besides that of Stereophile founder J. Gordon Holt, of course? It’s likely that no two audiophiles would ever come up with identical lists of subjects, but I wouldn’t be surprised if they could agree on at least one name: […]

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Ask our editor Neil McCauley: Who really designed the original Gale loudspeakers?

Hi Neil. Who really designed the original Gale loudspeakers? It was in fact Mr. Ira Gale. From all accounts Ira Dennis Gale was a genius, able to “talk his way in and out of anything”. He also tended to “stir the pot”, and may have enjoyed doing so occassionally. Born on December 4th, 1942, Ira […]

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Re bi-wired speakers, how important is the type of jumper? Dr Richard Bews responds

Recently I wrote: This started way back at Subjective Audio in the 1980s I played music for the staff on our reference system, then going around to the rear of the speaker, making a quick ‘mystery’ change they all noticed for the better. What I did was simple; I moved the speaker cables from the […]

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AUDIO NOTE: Peter Qvortrup talks three-motor turntables

Rafe Arnott: I had the rare opportunity recently to catch up with Audio Note UK head honcho, globetrotter, music lover, and hi fi-industry legend Peter Qvortrup, who graciously agreed to be assailed with questions by me regarding what his company has up its sleeve for 2016. Qvortrup is a man I’ve offered to drink beer […]

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AUDIO NOTE: Peter Qvortrup interviewed

Kari Nevalainen: Audio Note UK participated in the Helsinki HifiExpo 2011 with a system that comprised of AN-E/SEC Signature loudspeakers, ANJ UK’s Onkagu integrated, Level Five CD-transport and Fifth Element DAC, the AN-TT Two turntable with the new ARM Three and IoI MC cartridge, M9Phono pre-amplifier, and AN-SOGON cables. Many were truly impressed by the […]

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COLIN WONFOR: The fine art (or science, or both?) of cable design

Colin, what are the current design and materials limitations that confront all intelligent skilled speaker cable designers today? It is not materials! it’s understanding that block A can go with block Z. The complex nature of the cable is not a easy thing to write here about.  And I will not be writing about the […]

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HELIUS DESIGNS: Geoffrey Owen, founder, owner and senior design engineer writes about the 1983 Orion tone arm

The trouble with being an engineer is that one is born with a natural tendency to look at the world through critical eyes and consider how differently you might have designed the things around you had been have been given the job. But then, if ever you feel inclined to prompt such a discussion, most […]

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