Melbourne Audio Club

General Meeting Reports for 2025

December 2025

December DIY Report

This month we bring a collage of contributions from David, Richard, Stephen and Dave. There are also some static displays from Ron, Giscard, Mak, Alan and Alistair.

The first system for the night consisted of an Audio Aero La Fontaine Music Centre (provided by David), David's speakers and Richard's LJM L7 class AB MOSFET based power amplifier. The second system the source was switched to Dave's streamer plus DAC. The third system was Stephen's Lintwikz Pluto active speakers. All were quality products produced by our own members.

Once again the club was spoilt with excellent DIY products of an incredibly high standard. We could easily have been fooled against retail products rather than DIY. The first system demonstrated excellent system synergy, with Richard's amplifier complementing David's speakers very well. The twin 8-inch woofers delivered impressive bass performance, easily coping with low organ notes. When David played "You Do Something to Me" by Anthony Warlow, the classic paper cone sound, so familiar and loved by many shone through. Wynton Marsalis's "The Flight of the Bumblebee" highlighted the speaker's mid range vifa P17 ultra light polypropylene cone speed and dynamic capability. Revealing a highly dynamic presentation, albeit with a slight hint of harshness in the lower treble. Overall, the speakers were very impressive in the Willis Room, with superb build and finish quality. They would fit perfectly in a high-end retail showroom with a price tag to match. The tonal balance was excellent and stands as a true credit to the careful matching of the drivers, cabinet design, and David's crossover implementation.

Richard's power amplifier consisted of LJM L7 amplifier modules based on IRF MOSFET's, that have been very popular in audio applications for three decades. They have found their way into many high end products, including several of Nelson Pass's creations. The L7 modules were sourced from ebay at a cost of $70.00 plus postage, RS toroidal transformer $284.00, aluminium heatsinks and 2U aluminium case from Altronics. The total build cost for the parts was around $700. Richard remarked on the issues he had to overcome with setting the bias current and wiring. Richard's amplifier clearly demonstrated that good sound can be had for remarkably low cost with DIY. The amplifier has plenty of power and e ortlessly drove David's speakers. The mid range was accurate, dynamic and detailed. The top end was revealing and there was minimal distortion. Excellent result for such a low cost that would make a great first project.

David Dufin's comments. At the 2025 'buy, swap and sell' I picked up a set of speaker drivers previously owned by the late member Greg Kerr. The drivers proved to have been a fine choice by Greg. Not being endowed with great cabinet building skills I entrusted this job to John Woodhead of Aranmar Acoustics Audio & Furniture Manufacturers in Mentone. John has been building cabinetry for ages and does a first class job. He also has a computer program that can design a suitable speaker box, all you have to do is give him the parameters or the model of the drivers and the program will do the rest. I took full advantage of this service.

I had purchased a set of very cheap 3 way crossovers on the Internet just to get the project underway. The limitations of these crossovers were immediately apparent. Back to the Internet where I purchased some quite good quality copper caps and inductors. With further refinement of the component values I got a set of very decent crossovers with crossover points of 300Hz and 4kHz. I was happy with the sound and this became the final arrangement.

Fine tuning, I experimented a bit with damping material. Acoustic foam did the job in the bass reflex chamber and part of the contents of an old cushion suited the midrange chamber. Our speaker measurement expert, Ron Newbound, ran his impedance measurement software over the speakers and the results were textbook. It remains for the MAC members to make up their minds about the ultimate sound. The drivers are as follows: SCANSPEAK 21W/8556-01 woofers,( two per cabinet). VIFA P17WJ-00-08 midrange speakers. SCANSPEAK D2604/830000 tweeters. The speakers demonstrated at the December DIY are now owned by Alan who was good enough to allow my creations to be shown on the night. Thanks Alan

As I wanted to showcase the sound of these speakers at their best I bought along my Audio Aero La Fontaine Music Centre together with DIY AudioQuest Rocket 11 bi-wired speaker cables and AudioQuest Evergreen LGC interconnects. The amplifier on the night was a DIY creation built by member Richard Struthers. Richards' amp did a great job and I am very grateful to him for making it available.

The initial test was done using the Toccata opening from the CD "J S Bach Great Organ Works". To say I was nervous about how the speakers would sound in the Willis Room would be an understatement as many a fine loudspeaker has come to grief mainly thanks to bass resonances in the room. After a brief listen It was obvious to me that the Willis Room may have met its' match as the sound of the organ filled the room and I didn't detect any of the usual bass bloat I've experienced on some occasions. Maybe I should have bought along some of my favourite Wurlitzer CD's!

The large audience were subjected to music I like, artists we heard were Anthony Warlow, The Cotton Club Orchestra, Wynton Marsalis. Gershwin by Grofe, Black and White Affair and Todd McKenny. Thanks to all the members who said they liked my attempt at speaker building and the sound on the night. Flushed with this success I think I'll build another set to demo next year.

The second system was based on the first system, with the source changed to Dave Polanske's streamer with an inbuilt DAC. The streamer was built around a Raspberry Pi with a "top-hat" DAC based on the ESS9023 DAC chip. The software platform used was Volumio, which supports TIDAL Connect.

On the night, something sounded slightly of with limited volume and no top end, and Dave noted that the system was not performing as expected. See Dave's comments below for further details. It is worth noting that the Raspberry Pi platform is commonly used in many retail streamers, as is the Volumio software. In fact, it is not uncommon to find $3k-$8k retail streamers using this exact combination, albeit housed in a more elaborate enclosure.

Even though there were issues on the night it's important to recognise just how capable this platform is. For anyone interested in building their own streamer, this is an outstanding and proven DIY solution that o ers remarkable performance, flexibility, and value for money.

Damian

Dave's comments... A few notes on my Raspberry Pi streamer I brought along to the MAC DIY night: Components used: Raspberry Pi 3B+, Audiophonics ESS9023 DAC TOP HAT, Mean Well 5V power supply, case, switch and indicator lights from Altronics

Construction and configuration:

I purchased a variable power supply from Altronics as the Raspberry Pi needs a minimum of 5.1V. The Raspberry Pi operating system is an image file that needs to be etched onto a micro SD card. I went with with Volumio as it offers TIDAL Connect and Qobuz Connect, an excellent choice for a music streamer.

Once powered up the challenge was to connect to the WiFi, to my surprise it connected immediately to Starlink in the house. Once I knew the Raspberry Pi was working fine, I turned my attention to the DAC board. All initial settings are done through the Volumio app after which I use the TIDAL connect feature and remotely control the streamer through my smartphone. The streamer can be connected via wifi or Ethernet, for the DIY night it was using Ethernet and fortuitously we have that capability on the club's internet device.

I found the sound quality flat on the night. The sound can be user-adjustable as there is capacity within the DAC to set to a roll off for the top end frequencies. The DAC outputs 2V and I had it set at 500mV which limited the volume considerably. I will look further into this as it would be useful for anyone who wanted to build a streamer.

Dave Polanske

The third system of the evening was a fully active setup, with all components supplied by Stephen. The system comprised a Raspberry Pi streamer, Topping D10S DAC, and Linkwitz Pluto active speakers. The speakers are semi-omnidirectional, employing a 5-inch midrange driver that fires upward toward the ceiling. The cost to build the speakers is around $1,500. They can be used in conjunction with a pair of 10 inch open ba le subwoofers (designed for the Linkwitz LX mini), the subwoofers were not used for the demo.

Physically, the speakers are compact, with cabinets comprised of plumbing pipe sourced from plumbing suppliers. While they may not score highly on the wife approval factor, their small size and light weight mean they can be easily packed away when not in use. On the night, the system was demonstrated without the subwoofers, naturally limiting low frequency extension. The top end is also constrained due to the use of a 2-inch driver, although this limitation lies beyond the hearing range of many members. Furthermore the speakers have limited maximum SPL and cannot be played at high volumes. As Siegfried Linkwitz himself commented regarding this limitation: "just sit closer to the speakers."

Despite these constraints, the performance was outstanding. Beethoven's Violin Sonata and Alexander Melnikov, was remarkable. The speakers completely disappeared, creating the illusion that the piano was physically present in the room. There was no hint of cabinet resonance, and the tonal balance was exceptionally natural.

Stephen concluded his presentation with "Anything Goes" by Tony Bennett and Lady Gaga. The upbeat rhythm and beautifully reproduced vocals had the audience toe tapping along to this modern interpretation of a classic American swing jazz standard.

Taking all limitations into account, the midrange performance of this system was simply superb. The midrange was arguably the best presented in recent years in the Willis Room from any system, at any price. History: Siegfried Linkwitz (1935-2018): The original design appeared on Linkwitz web site in 2005 as a low cost DIY project. It is designed for relatively close listening position in room, in larger room it is advised to just add more distance behind the listener.

I made an original version in 2008 purchasing PCBs and construction notes from Mr. Linkwitz, using a peerless paper base driver. In 2010 they were updated version 2.1 using a seas 5 inch aluminum base driver capable of greater excursion allowing more base output along with some new response EQ adjustments to the electronics.

Details: The Pluto is Omni directional up to about 3 KHz then becoming directional at higher frequencies up to about 15 KHz. The Omni directional operation is as Linkwitz said "illuminating the room uniformly over a very wide frequency range; thus room reflections sound the same as the direct sound, this helps creates a more natural sound. Refer Linkwitz site Pluto introduction. The vertically facing Base driver is mounted on a rubber pipe coupler connected to 4 inch pressure pipe. This makes an extremely rigid PVC sealed enclosure with very little radiation from the walls. In order to prevent pipe resonance the tube is filled with a mix of polyester and teased out wool, resulting in about 40dB return loss from end of pipe reflections and additionally there is a notch in the electronics to further reduce remaining half wave pipe resonance.

The forward firing tweeter is an Aura 2 inch full range open back driver. It is mounted in 2 inch pipe positioning the tweeter over the base driver and provides the enclosure for the tweeter. The placement of Aura driver and Base driver results in close time alignment of acoustic centers, an additional all pass circuit corrects the phase shift due the small offset in acoustic centers between woofer and tweeter. This results in operation something close to a point source. Electronics The Pluto is an active 2 way speaker and has separate amp for each driver.

It requires line input only, the analog electronic crossover is 4th order Linkwitz Riley at a low 1 KHz. Crossover and EQ is made using op-amps Power amps are chip amps, 2x LM3886 in bridge for the bass and a single LM3886 for the tweeter Power supply has a low power 50 VA transformer and 20,000uF capacitors on each supply rail EQ for the base driver allows the small enclosure to achieve -3db at about 40 Hz for the 2.1 version)

Limitations / compromises Maximum volume is limited mostly by the drivers that will overload when playing too loud. No real tweeter, limited by the 2 inch driver so no tweeter sparkle (not a problem to me) No deep base limited by the 5 inch driver (still it has surprising base for its size).

The Pluto has a unique look where form follows function; it is an example of innovative and clever design from Linkwitz with a spacious sound that's hard to beat in an average sized room. However I was concerned that they would be lost in the Willis room's large space. They probably sounded best at the front of the room. In the Willis room they were working hard, near their limits on demo, but still showed what well designed small speaker can do. When correctly positioned in a normal sized room they have an ability to create a stable image and seem to disappear.

Stephen

The Richard Allan speakers I brought along to the December DIY meeting belong to my brother's friend and they have been in a cupboard for 50 years and are unused. I was asked to assess whether they could be used in a speaker project. I haven't done the testing yet but I thought it would be good to bring them along to show everyone what was available to the Diyers back in the 70s.

Ron

SET 805 final stage amplifier. The timber board is a test bed for designing valve circuits and has a variable 0 to 1,600 volt DC power supply. Tube heaters are powered by LiPo batteries. It currently has a single stage, single ended 805 tube, with the tube's heater currently powered by a battery, it's electrically safe!

It has just three components, an input transformer - the 805 triode tube - and an output transformer. It can produce 50 watts into an 8 ohm load of singled ended output, when driven by a slave amplifier of 20 watts output. The design & testing of this amplifier was completed some time ago and it is now under construction. The black vertical box is the power supply, containing a full wave rectified, three stage Cockroft-Walton power supply outputting 850 volts DC (B+). The tube heaters will be powered by the two 12.8V 60AH lithium batteries, that enable upto 15 hours of operation. The box itself is a modified computer server cabinet, as these are well made and cheap to buy.

The amplifier will be housed in the black Hammond chassis from Canada, fabricated from mild steel and recently milled by Speith Engineering in Bayswater.

Damian Ware
MAC President

November 2025

Rockian Trading

The following is a summary of the items presented at November's General Meeting, kindly supplied by Ian Hooper.

Once again we thank Greg and Yvonne Osborn for providing the wonderfully appropriate audio equipment for the meeting. The Consonance amplifier and disc player coupled by Greg's custom made cables to a pair of Osborn Epitome speakers. This system filled the Willis Room with gorgeous sound. With "just the right amount of detail."

The first two recordings were significant items from my private collection and not for sale.

1. Walk Don't Run, The Ventures, a tune copied by The Ventures in 1960 from the Chet Atkins arrangement. The swing jazz tune was written by Johnny "guitar" Smith. This record inspired me to save money working at the family farm, 8 miles north of Benalla, to buy a red Top-40 Vibra-Twin electric guitar. So I began my life and adventures in music and technology. This is a story I would love to share with the Club at a future meeting, playing the appropriate tracks as we progressed. I started preparing that program but realized it would take too much time out of tonight's program. So, I will start with a short description of how Fleetwood Mac came about. I will play their first big hit featuring the guitar skills of Peter Green and Danny Kirwan. Both were severely damaged by contaminated LSD at a party in Germany when touring to support Fleetwood Mac's first releases.

2. Albatross - Fleetwood Mac single. November, 1968. From my private collection, a hit world-wide. After this Fleetwood Mac made 8 studio albums before the addition of Lindsey Buckingham and Stevie Nicks. Mobile Fidelity will release The Fleetwood Mac self titled LP (also known as The White Album) on a Limited Edition One-Step 180g double LP (LMFUD1S 065) and a Ultra Dynamic Hybid SACD (UDSACD 2311) later this year. The following demonstrations are from Mobile Fidelity Sound Laboratory

3. Mirage - Fleetwood Mac. (UDSACD 2283) July 1982. The 13th studio album has 5 hit singles, Hold Me, Gypsy, Love In Store, Oh Diane, and Can't Go Back. I will skip through these tracks 1, 2, 5, 9.10. Pick a track, any track hit album.

4. Jagged Little Pill - Alanis Morissette. (UDSACD 2281) "Post Grunge." Grammy Winner for 5 Album of the Year awards, Best Rock Album, Best Female Vocal, Best Female Performance (You Oughta Know) Best Rock Song and best Long Form Music Video. After her promotion tour of the Pill album and frequently performing the painful You Oughta Know she sought treatment for PTSD.

5. Supposed Former Infatuation Junkie - Alanis Morissette (UDSACD 2284) Show only.

6. Dangerous - Michael Jackson - (UDSACD 2289) The first 6 tracks are looped dance grooves, interesting but tedious to my old ears. Starting with track 7, Heal The World the rest of the albums 14 tracks are pure art.

7. Listen To The Music - The Doobie Brothers - (UDSACD 2041) The second Doobie Brothers album is about to be released on a double 180 gram double 45rpm LP. When this was first released I wore at least 2 cassettes out driving around in my Hi-Ace Van. Another pick a track any track great album.

8. Bookends - Simon and Garfunkel - (UDSACD 2257) Show only. This is not really a Simon and Garfunkel album, more like a collection of out-takes, found sound pastiches, and one Paul Simon song that featured in a movie.

9. One Of These Nights - Eagles - (UDSACD 2232) Another pick a track any track, great album. The outstanding track for me is the story of Lyin' Eyes. 10. Prisoner in Disguise - Linda Ronstadt - (UDCD 777 gold CD) This is scheduled to be released as a double 45rpm LP.

11. No Secrets - Carly Simon - (UDSACD 2167) And yet, the track You'r So Vain has so many secrets. A great recording from when the world was young, with so many stars sitting in. Soon to be released on double 45rpm LP.

12. Billy Joel - Piano Man - (UDSACD 2062) A quality 1973 pop song who enjoyed a long residency gig at Madison Square Garden in New York from January 2014 to July 2024. The music of Billy Joel was recently featured last Friday 14th and Saturday 15th of November in a show titled "Piano Man" by The Melbourne Symphony Orchestra at Hamer Hall. For Billy Joel fans Mobile Fidelity has remastered his significant catalogue. Most of these recordings have sold out and the last issue, the Greatest Hits double SACD. Now selling for handsome amounts.

13. Miles Davis - Sorcerer - (UDSACD 2145) Show only. It has recently been released on MFSL Super Vinyl.

14. Miles Davis - Bitches Brew - (UDSACD 2 2149) Show only. Soon to be released on One Step vinyl.

15. Miles Davis - Sketches of Spain - (UDSACD 2086) This has been released on One Step vinyl.

16. Simon and Garfunkel - Parsley, Sage, Rosemary & Thyme - (UDSACD 2199) - Show only, This has been re-pressed on MFSL Super Vinyl

17. Santana - Santana, Abraxas and Caravanserai - (UDCD 773, UDSACD 2152 & UDSACD2079) Show only. All of these titles are being pressed again as single MFSL Super Vinyl LPs. We have not received any new classical records this year. Besides, we no longer have any quality classical music stores. So, we explored our stock to find neglected back catalogue masterpieces. We found these fantastic SACDs from Cala Records. Cala Records went into suspension several years ago when Geo rey Simon, the CEO and Chief Conductor, resigned to take a partnership with his brother in their family trade building developments, in the London Harbour precinct.

18. Granger: The Warriors - Melbourne Symphony Orchestra, Geo rey Simon - (CACDS 4033) An Aussie conducting an Ausie orchestra performing Aussie compositions in an Aussie town hall. Here presented on SACD. There are only a few left.

19. Saint-Saens: Africa - London Philharmonic Orchestra - Geo rey Simon - (CACDS 4031) Show only. This could be three concerts on one disc. It is exciting and dynamic.

20. Saint-Saens: Requiem & Organ Symphony - London Philharmonic Orchestra - Geo rey Simon - (CACDS 4032) Recorded at All Hallows Church, Gospel Oak, London with the Grand Organ in Westminster Cathedral for the symphony.

21. Ravel: Valley of the Bells - London Philharmonic Orchestra - Geo rey Simon - (CACDS 4026) Ravel's original work for piano is here orchestrated by Percy Grainger for orchestra and "any melodic percussion instrument." The Piano Concerto in G and the Five Popular Greek Melodies are also absorbing.

In the 60s Geo rey studied with several of the name conductors in Europe, but his biggest influence was Leopold Stokowski. Like Stokowski, Geo rey was more a "Showman" and less a "Conductor." His freehand and fluent style encouraged more passion from his orchestras than the strict tone and tempo of his contemporaries.

As always my sessions with the Melbourne Audio Club seem too short. Thank you all for listening and engaging.

Ian Hooper
Rockian Trading

October 2025

Russell & Martin Lenehan - Lenehan Brothers

At our October General Meeting, Russell & Martin Lenehan from Lenehan Brothers presented the System 1 loudspeakers with Grandinote Supremo Integrated Amplifier and the Grandinote Volta Streamer/DAC as source. He used Foil Flex speaker cables and XLR line level interconnects. The Grandinote Supremo Amplifier is a mosfet Class A rated at 37W per channel. Unusually for a solid state amplifier the Grandinote Supremo featured an output transformer.

The System 1 is a premium two-way stand mount loudspeaker designed for uncompromising musical performance. The System 1 features a SEAS Excel 19 cm magnesium cone mid woofer paired with a Morel 28 mm silk dome tweeter. The cabinet construction is unique, crafted from solid timber and reinforced internally with dual metal layers. One of these layers is steel and the other of aluminium; to achieve outstanding rigidity and vibration control. The System 1 features a 3rd order crossover network set at 1.5 kHz. Despite their compact form, the System 1 loudspeakers are substantial in weight, tipping the scales at 30 kg each, a testament to their dense multilayer cabinet. Connection is handled via ETI Research binding posts, accommodating a wide range of high quality speaker cables.

To support the substantial 30 kg weight of the System 1 loudspeakers, Lenehen Brothers provide a set of heavy duty stands. These stands feature an innovative isolation system that departs from traditional design philosophies. Instead of rigidly coupling the loudspeaker to the floor using spikes, the October General Meeting Report System 1 stands employ a flexible mounting mechanism consisting of rubber and spring elements. This design yields a resonant frequency of approximately 2 Hz, providing isolation from floor. When gently pushed, the loudspeaker and stand assembly can be seen to wobble slightly, a result of the very compliant suspension system.

To further stabilise the system and control any residual motion, Lenehan Toppers (tuned mass dampers) are placed atop each loudspeaker. These devices are intended to counteract unwanted movement while preserving isolation benefits. This decoupled isolation approach runs contrary to the long-standing convention of rigid spike coupling, where loudspeakers are mechanically rigidly coupled to the floor. However, similar philosophies are now being explored by companies such as IsoAcoustics, suggesting a shift in thinking toward vibration isolation rather than rigid coupling. Whether this low-frequency compliant system provides a superior sonic result remains a matter for the listener's preference.

The System 1 loudspeaker represents quality Australian craftsmanship, featuring locally sourced hardwoods such as Ironbark and Spotted Gum. This excellent loudspeakers presents a rustic appearance with the warmth and texture of real wood.

The playlist for the evening was presented by Dave Polanske and Russell Lenehan and a link to the full playlist can be found below. The music began with Anette Askvik, 'Liberty', a stellar recording featuring female vocals, piano, cello and a superb Tenor Saxophone solo by Petter Wettre. The Saxophone featuring an exceptionally dark and breathy tone. The piano, cello and saxophone were faithfully reproduced without colouration and Anette's vocals were clear, forward and without sibilance. Dave then he played Nils Lofgren, (live acoustic) 'Keith Don't Go'. This piece amazed with every micro detail of the guitar strings, fingering and body resonance, all rendered with precision. The next song was Gojira, 'Drum Solo' playing the lowest note B0, (approximately 30Hz). This proved to be too demanding for the Seas Excel mid woofer. Considering the size of the Willis Room this was not unexpected and would unlikely to be an issue if used in a small room.

After the break the members resumed their seats to hear 'I'm Confessin' (That I Love You) from Dean Martin's 'Dream with Dean' Album. Dean's vocals provided a great centre image. The evening ended the presentation with Fleetwood Mac, The Chain. On this piece the System 1 speakers and Grandinote Supermo amplifier delivered a good performance.

Thank you to Russell and Martin Lenehan for presenting the System 1 speakers and Grandionote electronics. It was an unusual combination, very Australian and Italian, and delivered a very unusual experience for the Club members.

Meeting playlist (Tidal): https://tidal.com/playlist/343c90ac-589c-45dd-8c25-744aec98f6ac

Damian Ware
MAC President

September 2025

Corsini Acoustic Solutions

At our September General Meeting, we had the pleasure of an engaging and insightful presentation by Cristian from Corsini Acoustic Solutions. Cristian shared several real-world examples of rooms he has treated, providing detailed descriptions of both the system setups and the acoustic treatments applied.

Cristian's presentation included before and after photos and results, clearly illustrating the impact of proper treatment on sound quality. Some key takeaways from the session included:

System setup is critical: Speaker positioning and the listener's placement in the room can significantly influence sound quality.

Active bass traps are particularly effective in the 15-150Hz range, where traditional passive solutions can be either ineffective or require large and intrusive constructions.

Christian also showcased a wide variety of high-quality acoustic treatment products that he has access to, offering valuable insights into what's available for both enthusiasts and professionals.

A big thank you to Christian for taking the time to share his expertise and services with our members!

Damian Ware
MAC President

August 2025

Elektra Amplifiers

At our August General Meeting, Arthur Rappos from Elektra Audio presented the Elektra HD2 Power amplifier and Brodmann F2 speakers. The Elektra HD2 is a multichannel power amplifier rated at 175W per channel into 8 ohms with 0.001% THD @100W. The Brodmann F2 speakers featured 2 x 5" side mounted drivers and 25mm front mounted tweeter. The source for the evening was the club's WiiM Pro Plus streaming Tidal.

The Elektra HD2 power amplifier presents a classic aesthetic, featuring a minimalist front panel with a single, blue illuminated power button and a sleek black finish. Offering seven channels of Class AB amplification; the unit is remarkably compact. The Elektra HD2 is a powerful addition to any high performance home theatre or 2 channel system.

Paired with the Elektra HD2 amplifier were Brodmann F2 loudspeakers. With a slim, elegant form factor and high gloss piano black finish these speaker exude sophistication. Visually understated yet luxurious, the Brodmann's deliver a design that blends seamlessly into modern living rooms - easily meeting the coveted "spouse approval factor."

Arthur provided an entertaining and sporadic presentation, captivating the audience with deep observations into technical design and thought-provoking controversial topics. After an overview of the equipment specifications, he gave a detailed description of his approach to amplifier design. Arthur's approach is methodical, measured and uncompromising, focused on faithful reproduction of the source. Using accurate spice models Arthur uses advanced circuit simulation tools to evaluate his designs. Virtual prototyping enables evaluation of distortion, precise tuning of feedback networks and rock solid stability before any physical circuit is built. The next stage is PCB development followed by mechanical integration and rigorous listening tests.

The playlist for the evening was provided by Dave Polanske, Bailey White and Arthur Rappos, a link to the full playlist can be found below. Starting with George Ezra's Budapest George's crisp unique voice was faithfully reproduced without colouration. Then he played Handel's Apollo e Dafane, HWV 122 to demonstrate the high dynamic range of the system. The female vocals were clear without sibilance, building the emotional tension. Steely Dan, Aja a features sophisticated cords, (typically used in jazz) with a shifting rock time signature. Aja was a delight, the percussion was dynamic, keyboard was accurate and Wayne Shorter solo tenor saxophone was unmistakable dark, slightly raspy.Brilliant.

Rather than relying on rare and boutique parts Arthur has optimised his design to use mass produced main stream parts. These parts such as Nippon Chemi-Con capacitors have tight tolerances and are extremely reliable. Mass produced parts, are also utilised from multiple reputable international suppliers, minimising part chain supply issues and reducing cost.

After the break the crowds returned to their seats to hear Dead can Dance's, 'Rakim'. The sound expansively filled the Willis room. With an extensive mix of percussion, ambient textures and layered electronic effects this track is a complex test for any amplifier. The Elektra HD2 was effortless, handling Rakim with ease. The Brodmann speakers were superb in the upper registers, but did show some signs of stress with the deep notes, given the speakers use 2 x 5" drivers and the size of the Willis room the speakers exceeded expectations. In a small living room or apartment the Bodmann F2's (I would expect) the bass output would be sufficient for most listeners.

Arthur didn't shy away from addressing some of the more difficult topics and beliefs in the audio industry. He explained that higher priced products do not always correlate with better performance and that the influence of 'Golden Ears' in subjective evaluations was problematic. Arthurs engineering based comments were well received by the members and lead to some lively discussion with members relaying their own similar experiences.

Ending the presentation with George Harrison, My Sweet Lord the Elektra HD2 and Brodmann F2's delivered both excellent performance and timeless understated visual appeal, ideal for listeners who value both sonic excellence and design harmony.

Meeting playlist (Tidal): https://tidal.com/playlist/63afe7db-bfd8-4d4d-8b33-aafd44b9fa78

Damian Ware
MAC President

July 2025

Kevin You from Class A Audio

At our July General Meeting, Kevin You from Class A Audio presented the Boulder 866 Integrated amplifier and Audiovector Trapeze RI speakers. The Boulder 866 has a built in Roon Ready streamer, full colour touch screen and internal DAC. The 2ch amplifier is rated at 200W per channel into 8 ohms, 0.01% THD and 150kHz bandwidth.

The Audiovector Trapeze RI speakers are a reimagining of the original Audiovector Trapeze released in 1979. The Trapeze RI have the same cabinet design as the originals using completely new drivers, crossovers and internal wiring. They featured a 12 inch woofer with an internal 8 inch woofer in isobaric configuration, 5 inch midrange and AMT tweeter. The source for the evening was Qobuz streaming via Roon.

The Boulder 866 had a classic appearance with a silver finish. The colour touch screen wasn't overstated and was a nice highlight. The front panel was sloped back, with a matching look to the sloped Trapeze RI speakers. The Trapeze R1 feature a unique cabinet with a sloped front baffle and multiple angles to eliminate internal standing waves. The mid range and tweeter were offset and had a section of sound absorbing felt to reduce edge diffraction.

The cabinetry and finish of the Trapeze RI was superb. It offered complicated angles, a seamless finish, and a perfect woodgrain alignment. Attention to detail was exceptional, a credit to the creators.

After a concise explanation of the equipment the audience was impressed with Stacey Kent's La Valse Des Lilas. The tenor saxophone, played by Jim Tomlinson, was smooth and filled the room with a very large sound. Stacey's vocals were dead centre slightly forward of the speakers. Keven next played Simone Kopmajer's Nothing's Gonna Change My Love for You, and the system once again showed the large sound as the speakers completely disappeared.

Jacky Fung, the sales manager of Audiovector for South Pacific, provided a demonstration of the significant difference between the speed/ resistance of the commonly used aluminium vs titanium former in the Trapeze RI. When inserted into the motor structure the aluminium former creates eddy currents that increases resistance and reduces the speed at which the voice coil can traverse. The titanium former allowed the voice coil to be inserted with no such resistance, bringing faster transient response and better dynamics particularly when listening at higher SPLs.

The benefit of the titanium former became clear when listening to Leopold Stokowski & July General Meeting Report RCA Victor's Hungarian Rhapsody No. 2 in C Sharp Minor, as the system revealed every quiet micro detail whilst effortlessly hitting the low notes.

The Boulder 866 demonstrated a high level of driver control with tight and fast percussion with clean decay with Dacoit Duel from A.R. Rahman & Matt Dunkley. Next Kevin played electronic music - Francine Thirteen's Queen Mary. The system was able to demonstrate exceptional dynamics and very high decibels in the large Willis Room. The Boulder 866 had power to spare, sounded effortless, and remained in complete control.

After the break the crowds returned to their seats to the lovely Chantal Chamberland's La vie en rose. The smooth warm female vocals caught the attention of the members with a slightly forward presentation.

Kevin ended the evening with the Eagles' Hotel California live acoustic 1994 MTV recording. The bongos, guitars and vocals lit up the room and sounded superb. Overall a great evening with excellent high end equipment. The Trapeze RI disappeared with a large sound stage and the Boulder 866 showed constant authority with no signs of stress. The system was capable of very dynamic high SPL whilst maintaining transparency. Thank you, Kevin and Jacky for a great entertaining evening.

Damian Ware

June 2025

AGM

Our meeting June 18th was the club's Annual General Meeting, as well as our Buy, Swap and Sell night.

The AGM is your chance to hear from the committee the state of our club. We will give you a run down on all aspects of the club so please come along and be informed! Pizzas and wine will provide refreshments for the night's activities. Of course, coffee and tea will also be available.

We also had our annual Buy swap, Sell for all to bring along there preloved but now unloved audio gear, DVDs, records, tapes, books, magazines and CDs.

Web Ed.

May 2025

Hugh Dean's Aspen Titan monoblocks

At our May General Meeting, Hugh Dean presented the latest iteration of his ASPEN Titan monoblocks. These are rated at 120W each and both monoblocks use a 300W power supply. They were fed from a laptop using MediaMonkey software, and on the night used high resolution audio files via USB to the state of an art SMSL D6S. This DAC uses the latest audiophile ESS DAC chip and includes an analogue preamp. The speakers were Adelaide Speakers Ascension model, upgraded by our very own speaker guru, Ron Newbound. They now sport a SB acoustic Satori mid-range and tweeter, with custom made cross-overs to suit.

In my 35+ years MAC experience few presenters have ever provided handouts detailing the equipment for the presentation. Yes, on occasions, there has been some generic marketing material available near the gear for those interested. But, NO-ONE ever provides a running playlist with additional explanations of the gear and music choices. Every member received this playlist at entry to the Willis Room. In one thoughtful master stroke Hugh made them all look amateurs.

He supplied a single A4 print out with a concise technical explanation of the audio system on one page, and the full playlist, including track, artist, date, bitrate and a brief comment, on the other. The playlist ensured all members could see what was coming next and what to listen for. So simple, so easy to follow and it kept the audience engaged.

In between the fifteen tracks Hugh gave us a brief description of each stage of his amp design and how each was implemented. His in-depth technical explanation of the inner workings of the amplifier was progressively revealed.

The ASPEN Titan uses a singleton input topology, unlike 99% of solid state amplifiers that use a long tail pair. The singleton has the advantage of producing dominant 2nd harmonic distortion, phased at negative 90 degrees which Nelson Pass confers depth of image. This is in contrast to most solid state amplifiers which are dominant 3rd harmonic distortion.

The next voltage amplification stage uses a very high quality fast transistor bootstrap loaded with meticulous compensation to ensure stability. The final stage, the output section, comprises two pairs of bipolar transistors in Emitter Follower Type II configuration, designed for 4 ohm loads, dipping to 3 ohms. Hugh spent weeks to identify the best operating points for this critical stage. For driving even more difficult speakers he suggests the preferred 200W MAYA.

Both designs deliver very high stability margin and utilise a modified differential nested feedback first proposed by Professor Ed Cherry from Monash University in the seventies. In essence, this power amplifier bristles with modern innovation which works very well with the inevitable harmonic distortion in all amplifiers so that it can be manipulated to offer a musical sound.

And what of the equipment and its sound in the notoriously "sound killing" Willis Room? Very, very good. As you might expect the ASPEN Titan monoblocks delivered the goods to his substantially modified Adelaide Speakers. This system filled the room with a very engaging sound.

Hugh's music choices were mainly Jazz and Classical. However, he started the evening with a very high resolution Fleetwood Mac track, "You Make Loving Fun" showing depth of image and great dynamics. Hugh commented "Titan's global feedback is limited to 30dB as beyond that level we tend to lose the depth of image." Being a bit of a Pop/Rock guy I would've liked one more of this genre but overall it was an excellent selection as each track had been meticulously chosen to illustrate specific characteristics of the system.

The Jazz at the Pawnshop album track was "How High the Moon", and featured Arne Domnerus playing Saxophone and Clarinet providing wonderful ambience. The presentation starkly revealed a myriad of little details such as the cutlery being used by the audience.

After the break Hugh introduced the audience to Alan Walker's "Time", an electronic variation of the Hans Zimmer's "Time" composed for the movie Inception. With the electronic synthesiser at work this track demonstrated amazing dynamics with powerful deep bass.

Hugh ended the evening with Mussorgsky's "Pictures of an Exhibition" delivering an amazing sound stage with large scale and height. Research and development is still ongoing at ASPEN Amplifiers with a new amplifier utilising error correction topology currently in the skunk works.

All in all, an absolute delight of an evening. Beautifully crafted, brilliantly presented and an absolute delight to experience. Thank you Hugh.

Matt Jelicich with additions from Damian Ware.

Apr 2025

An epic rock MAC gig

On the April Meeting MAC members were treated to an epic rock presentation at the Willis Room. It was 'The Winter of Discontent', the opus magnus of our esteemed Matt Jelicich and the leader of a rock band, Danny Lopez. We also enjoyed an accomplished choir comprised of four ladies and four gentlemen. All presenters were professional and very talented, but more on that later...

As you may know, Matt was raised an only child in the difficult period immediately after WWII. Life was tough and driven by survival, and most people of that time preferred a salaried, business pathway. Raising and supporting his family took centre stage and his "scribbling" (his term, not mine) became a background indulgence. During Covid, Matt quickly realised that much of his earlier 'scribbling' related to the "new" Covid world. He was motivated to complete a dark epic, conveying his alarm of our world as it slipped into pandemic, distorting our institutions, changing our governance, stripping our freedom and mental health. As a wordsmith Matt has a great love of Leonard Cohen, and an awareness of the dark aspects of the human condition. Our resourceful Programme Co-ordinator, Dave Polanske, encouraged him to present his work to the Club.

The evening started with Matt introducing us to his work, its origins, and a hint of its meaning... he warmed up the audience very well, but we did not glimpse the deep intent in his lyrics and Danny's music. The performance began with the full ensemble of musicians and singers, a rock ballad which warmed up the audience to the "Winter of Discontent". It was followed by a beautiful rendition of 'Duke of Earl', a wellknown 50s piece sung by an acapella with four male members of the eight-member choir. The third piece was with all the singers gently backed by the band but lightly amplified, and the sound was wonderfully harmonising. It was very pleasing music, harking back to a brighter era of the US. The rendition showed the range and skill of the four part Acapella and set the scene for an abrupt mood change.

Next Danny, accomplished front man and composer of the music, performed a short but impressive guitar solo leading into "Winter of Discontent". This broke the stillness with Kane Skinner, the outstanding percussionist, Jon Lambousis, the bass guitarist and the eight-part choir. All instruments were amplified, and the 'Winter of Discontent' was very, very loud! The sound was redolent of Jimi Hendrix; Danny is a wonderful rock guitarist and vocalist. Matt's words were displayed overhead via slide projector, so the audience could see dramatic images and read off the lyrics.

We might describe the 'Winter of Discontent' as Rock. But with musical accompanist from Danny, his musicians with some recorded backing and words from Matt the situation transformed to a hybrid of rock music, protest song, and classical requiem. This most unusual work reminded me of Pink Floyd's 1979 'The Wall', Barry McGuire's 1965 'Eve of Destruction', and Benjamin Britten's 1962 War Requiem (words from Wilfred Owen). If that was Matt's intent, he certainly had our full attention!

Knowing Matt, I was not surprised by the darkness, energy and breadth of 'Winter of Discontent'. It was shocking, dystopic, highenergy and thought-provoking. In any conversation with Matt, we are always impressed with his sociable pessimism and his insightful cynicism, and these traits were in full song in 'Winter of Discontent'. I came away somewhat dispirited by his dystopian future where truth, freedom and democracy are corrupted; musically 'Winter of Discontent' was fast-moving; a magisterial, dramatic sound, a little discordant. It was charged with startling lyrics, suited well for a young generation, all the clearer for the lyrics and captions projected on the screen at the meeting's end. But philosophically the work reminded me of Richard Strauss' 'Four Last Songs' written in 1947-8, a year before he died. Strauss paints a picture of a dying civilisation and the effect is profound emotionally. Matt's piece left me with similar feelings; profound sadness and the loss of great future.

Any piece of great art in any form should leave us with a sense of wonder, and sometimes with a sense of unease and even a dark awareness of despair. Matt's words and Danny's music achieved these emotions in spades. We should be very grateful for Matt and Danny and offer admiration that Matt had the courage to create, produce and commit his work to our Club; very few of us would ever have the self-belief to present our own artistic work. The 'Winter of Discontent' was one of the presentations over almost thirty years in the Club I will never forget.

For those who did not attend and/or those who did but would like to revisit the finished work at a volume level better suited to their preference, here is the YouTube link:

https://www.youtube.com/watch?v=6piuSYuTso0

Hugh Dean
19th Apr 2025

March 2025

JayVee Technologies and HeyNow! HiFi

Our March GM was presented by Toby Taylor of JayVee Technologies and Geoff Haynes of Hey Now Hi Fi. Toby brought along of electronics from the Sound Performance Lab range driving a pair of Revival Audio speakers. In the first half he demonstrated a modestly priced streamer, around $600, paired with one of their mid-priced integrated amplifiers.

The demonstration, together with a varied and interesting music selection courtesy of Dave Polanske, gave a hint of what the system could do but when the streamer was substituted for a Mark Levinson turntable and one of SPL's monoblocks the sound became richer, possibly more valve like and definitely more engaging.

During the second half Geoff showed off the Kirmuss record cleaning system and was busy cleaning and drying a dirty record several times to demonstrate its effectiveness. Geoff played the record for us, then completed 3 cycles of the cleaning process, taking approximately 15 minutes. He then played it again.

To me the sonic improvement of the before and after cleaning process was quite noticeable, and most members agreed it was very apparent. I think a lot of them were surprised how effective this cleaning process is. It showed the Kirmuss RCM is worth considering as a means to get the most SQ from your vinyl collection as well as reducing the intrusion of clicks and pops during playback.

My sincere thanks to Toby and Geoff for their time and effort spent on their presentation and for providing us a great evening's entertainment.

Laurie Nicholson

February 2025

Tim Robbins and Ric Clarke from HRSA

Tim and Ric brought along an array of vintage Williamson amplifiers (valve, of course) to showcase the very great leap in practical amplifier design that Theo Williamson, a Scotsman, achieved in 1947. Tim and Ric's exceptionally entertaining talk was peppered with juicy morsels, including the cover of an electronic magazine of the time nominating the Williamson as "the amplifier to end amplifiers" (how often have we heard that claim made?) and a personal description of the dubious joys of adjusting the bias of an old valve amplifier when the adjustment potentiometer was un-insulated and carried 400 VDC. The two amplifiers on demonstration were fed by a very modern Technics SL-G700M2 streamer provided by the program co-ordinator, Dave Polanske. Dave also provided the Leak sandwich speakers, more of which anon.

In the days just before the meeting I had a couple of colleagues ask me what I thought about the impending demonstration. I explained in broad terms the historical significance of the Williamson amplifier and the novel design of the Leak sandwich speakers, and concluded by suggesting it could be a very interesting session but that I was afraid the system would struggle to fill the Willis Room. After all, the Williamson amplifier was rated at only something like 13-15 watts (on a good day, with a tailwind and a downhill slope) and the Leak speakers, despite being floor-standers, were likely quite inefficient and probably themselves rated at only 15- 20 watts. Having seem modern transistor and Class D amplifiers with power outputs that would rival those of a small nuclear reactor struggle in the cavernous Willis Room, I thought I had good reasons for some trepidation as to how the system would cope.

How wrong I was! The system made GLORIOUS music. (Note that I say 'music', not 'sound'.) Person after person I spoke to during the evening and afterwards, on the weekend, remarked on how magnificent the system portrayed music. One member, who I would describe as an ardent audiophile, said "They aren't hi-fi but they make fabulous music". Another, this time of more antiquated audio and musical interests, reported the set-up had among the best instrumental timbre he had ever heard (and he owns a pair of QUAD 57s, so that's quite some praise). He thought the rendition of the Dean Martin track was remarkable. I was won-over by the Elvis track played just after the coffee break: had "Can't help falling in love" (recorded in 1961 for Elvis' 1962 film Blue Hawaii - and in the film sung not to his lover but to his grandmother!) ever sounded so heart-felt, so emotive, so moving, so musically correct?

So, what was the equipment responsible for such unbridled pleasure? I'll start with the speakers, as I have a long-standing personal connection to the Leak sandwiches. The Leak sandwich speaker saw the light of day in 1961. It was called a 'sandwich' because the speaker cone was a thin (2 mm?) layer of expanded polystyrene foam sandwiched between two very thin layers of aluminium foil. The chassis was made of cast aluminium and the surround was made from cambric fibre. The bass driver was big at 13" and the cabinets themselves were also substantial (60 L) and - of course - finished in period-correct real walnut or teak veneer with a thick cloth grille. The tweeter was also a sandwich design, of 3" diameter, and it crossed over to the woofer at 900 Hz. Since the speakers were designed to be used with a valve amplifier, they had an impedance of 15 ohms. I believe this initial, large, floor-standing version was called the Model 2060.

I was seriously mistaken when I hazarded to guess that the system would be inadequate for the Willis Room. The speakers must have been far more efficient than I had guessed, as they had no problem at all in filling the room. I tried to find what their efficiency was via an online search, but came up with nothing. I now believe it must have been somewhere in the mid-to-high 90s (i.e. dB/watt at 1 m; and remember they were 15 ohm speakers). A very harsh critic might say the top-end was rolled off too - but what can you expect from a 3" cone tweeter with what would now be considered an impossibly heavy cone (i.e. it wasn't built from no beryllium or titanium or diamond wunder-material). In any case, it's likely that few of our members can hear beyond 10-12 kHz, so our hearing and not the drive units is probably the limiting factor. And, yes, the bass driver didn't plumb the depths down to stygian, sub-sonic frequencies: who cares? What the system did do magnificently was portray voices, and particularly male voices. Bravo. Was this because they were being reproduced by a huge (13") woofer that operated solo up to 900 Hz? Maybe.

The sight of these lovely floor-standing, realwood- veneered creatures brought back a flood of memories. About 25 years ago I owned a near-mint pair of their smaller and younger brothers, the Sandwich Model 200. They had a smaller (8") sandwich-cone bass driver and two purple (yes, purple!) 60 mm Mylar drive units, one for the midrange and the other acting as the tweeter. I drove them via a 1960s Japanese amplifier that went by the name of 'Star' which, if recollection serves me correctly, used four EL34 values in push-pull operation. It made a lovely, warm, comfortable sound, perfect for my office. Not a lot of deep bass, not a lot of extreme treble, but a magnificent mid-range and more than satisfactory dynamics. Once you get the mid-range right, who but lovers of heavy metal and other types of doof-doof needs ultra-extended bass or treble?

I say my Leaks were 'near-mint' because the cambric roll surrounds had hardened with age over the then 40+ years of their existence. I took them a speaker repair fellow, based in Northcote I think, and he recommended replacing the original sandwich bass drivers with some hideous, cheap, Chinese rubbish that had bright yellow cones (but obviously were not real B&W kevlar units, "copy-cat yellow" being then the choice of colour for the cones of nearly all drive units). I recoiled in horror at the thought, mentally equating it to the travesty of replacing the 4.2 L straight-six DOHC XK engine in an E-type Jaguar with a pushrod Chevy V8 on the grounds that the latter was more reliable. Barbarian. Instead, in what can be subsequently described only as a fit of madness, I sold the amplifier and speakers. And sold them for a pittance, such stuff being almost unwanted at the time by audiophiles who prided themselves on being totally up to date with all the most modern equipment. Three words describe that action too: Regret. Regret. Regret.

Now onto the Williamson amplifier. It has been described in innumerable reports, of which I have the published paper by Lankshear (1990), the magnificent unpublished paper by Stinson (2020), and the three-part series of books on valve amplifiers by Popovich (2016). Scott Frankland wrote a detailed three-piece analysis in 1996 and 1997 for Stereophile on the history of push-pull amplifiers and their relation to earlier, single-ended, typologies. The first of Frankland's articles (December 1996) described the historical precedents of the Williamson design, its dependence upon the earlier (1934) amplifier design by W.T. Cocking, and how in turn the Williamson became the basis for much further development by other audio designers. The invention of ultralinear operation by David Hafler and Herbert Kereos in 1951-52 was one such development.

The Williamson design first appeared in the April (Part 1) and May (Part 2) editions of Wireless World in 1947, and was updated in the August, October and November 1949 editions. Revisions suggested in the updates included a change from the original four L63 single triodes to the use of two 6SN7 dual triodes in the preamp stage. Interestingly, 6SN7 valves are still used today (my Cary uses them as phase splitters). Popovich (2016, p. 190) argued that "The Williamson's design was not novel even in its day. There is nothing in it that hadn't been seen before, except, perhaps, the triode connection of the [tetrode] output tubes. However, it combined a few clever design choices, resulting in a relatively simple yet (for the time) well performing package." Frankland (1996, p. 115) was slightly kinder, concluding that "Williamson's amplifier enjoyed unprecedented momentum in the marketplace" and "has become the prototype for feedback amplifiers the world over." Lankshear (1990, p. 153) was kinder still, concluding that "The real importance of Williamson's work was that he demonstrated that extremely low distortion was achievable by using plenty of negative feedback, combined with carefully designed output transformers. His design set a standard of performance that is still acceptable today."

Figure 1 shows the circuit diagram for the early version. You will see the use of L63 triodes in the pre-amplifier stage and two KT66 valves in the output stage. (The KT in the valve's name stands for "kinkless tetrode", the kinkless bit being a reference to the shape of the value's performance curve, representing an effective way to circumvent the similar improvement in response recently patented for pentode valves.) 'The rectifier valve was a U52. In summary, it is a four-stage, Class A triode design using deep global negative feedback (20 dB) and a push-pull typology for the output tubes. The fact it was a four-stage design is important because an additional amplification stage was required to recover the input sensitivity lost due to the use of the global feedback. A push-pull typology using triode valves was considered in the 1940s to be the optimal basis for the design of a high-quality audio amplifier (notwithstanding the triode's chief drawback, high input capacitance).

The Williamson amplifier is significant in audio design, and this is because it eliminated the multiple inter-stage transformers that had been widely used in earlier designs and it DCcoupled the first two stages, both innovations being critical in minimising phase shifts. Williamson recognised it was vital to keep phase shifts to a minimum with a push-pull, negative-feedback design, given that the output transformers were integral to the global negative-feedback loop. The transformers therefore had to be of exceptional quality, otherwise they would be responsible for introducing large shifts in phase at frequency extremes. Were these to develop, what was intended to be a global negative feedback loop would quickly morph into a global positive feedback loop. The amplifier would then become a massive oscillator - with disastrous results for your speakers.

The well-known and respected English transformer maker Partridge Transformers Ltd was responsible for building the output transformers. The primary required 4,400 turns, the windings divided into ten primary and eight secondary sections and as by Lankshear (1990) noted "all interleaved into two balanced halves." They must have cost a fortune to make, and the highlight the deep skill-base of the English audio industry immediately after WW2. Negative feedback was optimised at 20 dB, and levels greater than that, Williamson concluded, served little or no useful purpose.

By demonstrating an Australian-made amplifier of the time that used slightly smaller transformers than those developed by Partridge, Tim and Ric showed just how essential high-quality transformers were to the Williamson design. The single most critical component in any valve amplifier is the output transformer, and as Tim and Ric noted, these are the single biggest cost in a valve amplifier, commonly accounting for at least a third of the total. In this situation there will always be a financial incentive to use cheaper transformers, i.e. ones that are smaller, lighter, less complex, or use lower quality wiring or non-grain-orientated steel in the transformer core. Tim and Ric showed plots of output power and phase shift of the Australian model to show how the amplifier with the smaller transformers had a markedly poorer performance than one with the big, expensive Partridges. It was still a good amp, just not as good as the original design would allow had better (i.e. dearer) transformers been used.

The Williamson amplifier is astonishingly significant in audio history because through it Williamson proposed - and then implemented - a set of design specifications that still hold today. Slightly later than its 1947 debut,

Williamson collaborated with Peter Walker (of QUAD fame) on an article published in a 1952 issue of Wireless World that expanded upon these requirements: Total non-linear distortion (i.e. harmonic and intermodulation) should be less than 0.1% at all power outputs (1-2 % was typical for the time) Linear frequency response within the audible spectrum of 10 Hz to 20 kHz Frequency response should be better than -3 dB at 3 Hz and 60 kHz, in order to minimise phase shifts through the audio bandwidth (40 Hz to 10 kHz + 1 dB was typical at the time) Phase shifts within the entire audio bandwidth should be less than 20o, in order to prevent the amplifier becoming an electronic oscillator Good transient response, with a power supply sufficient to accommodate large dynamic peaks in the music Output impedances as low as possible, and always "much less" than the speaker impedance, in order to provide adequate electric damping and limit undesirable peaks in the bass response of the speaker Hum and noise at least 80 dB below the maximum output. They concluded (p. 357) that this was "a formidable specification, and by no means every amplifier styled as "high quality" will meet it."

Nevertheless, specifications as tight as these were required because of the very great advances in recording quality that had been made in the late 1940s. An example is the introduction in June 1948 by Columbia Records of the 33 1/3 rpm microgroove LP record; until then, far looser specifications for frequency range etc were acceptable as they were sufficient for the shellac 78s and (AM) radio broadcasts that then made up all the program material. Greg Milner, in his 2009 book Perfecting sound forever: the story of recorded music, showed the degree to which recording processes had been improved after WW2 (e.g. as seen in Decca's FFRR records), microphones and speakers had become much better as a result of wartime technical developments in sonar etc, FM radio broadcasts (invented in 1933 but first provided in 1948 in New Jersey), and tape recorders using high-frequency bias (a wartime invention in Nazi Germany by AEG) were just coming onto the market (e.g. the Americanmade Ampex Model 200 in 1948). What an exciting period it must have been for those interested in music reproduction in the late 1940s and early 1950s!

To conclude - we heard last month an amplifier that was designed in 1947, teamed with speakers that first saw the light of day in 1961. In other words, an amplifier from eight decades ago and speakers from six decades ago. What glorious music they made, and made on track after track after track, regardless of genre or period of recording. What perfect, unbridled pleasure they provided. And the track that stood out for me - Elvis' "Can't help falling in love" - was recorded back in 1961 too. In other words, at the same time the Leak speakers were introduced and thus also over six decades ago, recorded using valve microphones and mono valve tape recorders and valve mixing desks etc, etc, etc. Yet we are told relentlessly by audiophile manufacturers that "new is best", that the most recent amplifier and speaker designs are light years ahead of what was claimed as first-class only a few months ago, that only modern 196 kHz 24-bit recordings will do as sources, that we need at least 24, preferably 36, speakers in our living/music/ theatre room to obtain the best sound, and this must include at least six sub-woofers.

Rubbish to all that self-serving baloney. The Williamson amplifier/Leak speaker combination is a superb corrective to the debilitating audiophile disease of upgradism. It makes beautiful music and what our hobby is about is music, not which amplifier has 0.000000001% total harmonic distortion at 2 Hz at a rated output of 3 kW per channel. It provides a remarkable antidote to the Cult of the New. Thus my new credo: "Long live audio 'anachronisms'!"