Get to know our Vintage Blog moderator, Dr. Adrian Wu

Welcome to the Asia Audio Society, our little virtual community of audio fanatics for sharing ideas and experiences in sound reproduction. I am one of the contributors/moderators of the site and I would like to take this opportunity to introduce myself.

I grew up during the 1960s in Hong Kong, and my first introduction to music came from my piano lessons. It was de rigueur in those days for kids to take up a musical instrument, and my mom probably chose the piano because we happened to have one at home, and the noise it generates is easier to put up with, as compared to say a violin or a trumpet. At the beginning, my enthusiasm was lacklustre to say the least, until I was sent away to an English boarding school and met my second teacher. He was a retired concert pianist who devoted his later years to nurturing the next generation. And for his sins, he ended up with me as his pupil. Nevertheless, his enthusiasm was quite infectious and I soon became fanatical about the instrument and music in general. In those days, having a boom box was a real luxury, but after the Sony Walkman became available, it was a revelation. In sixth form, a few of us in the A-level physics class formed an electronics club, and our physics teacher would teach us all the basic skills in soldering and putting things together. One Sunday afternoon, we went round to his house to help him work on his speakers. It turned out that he had these large, bronze coloured flat panels that looked like space heaters. He took the grill off one of them, put his hand in to disconnect a panel, and suddenly he was thrown back about 5 feet, landing on his backside with sparks flying. He did not discharge the things overnight as instructed, and all of us were duly impressed. From that point on, I lusted after a pair of Quad ESL57. The electronics training was very valuable, as proper technique and a good understanding of fundamentals is essential for our hobby, and so is the appreciation for safety, undischarged electrostatic panels notwithstanding. We learned to build power supplies, radios and even a robot controlled by a Motorola 6800 microprocessor.

I was able to secure summer jobs during my university days in Scotland and finally saved up enough to buy myself a music system. It comprised of a Systemdek II turntable (the “pressure cooker”), with Mission 774 tonearm and Audio Technica AT33 cartridge, which apparently is still available new 35 years later. I had a Mission Cyrus integrated amp and a pair of KEF Coda 3 speakers. All second hand, of course. I spent most of my spare cash buying LPs. I could not afford the flimsy new LPs, especially those miraculous digital recordings, which cost about ₤5 in those days. CDs just started appearing at that time, and they sounded so horrible to me even though they were supposed to have perfect sound, and they cost more than ₤10 each, so I opted to stay with imperfection. Sadly I had to settle for second hand LPs such as the narrow and wide band Deccas, postage stamp EMIs, Columbias SAXs and Lyritas etc. One would pay 50p to ₤1 for these. Fortunately, the Scots were frugal people and they took care of their possessions. LPs from those days still form the bulk of my collection. I used to salivate over my classmate’s Linn/Naim system. I remember him dragging me along to audition the LP12 at a dealership in Edinburgh. The salesman (a kid actually) brought out the turntable, had nowhere to put it and plonked it on top of the cardboard box it came in. The subchassis was bouncing literally sideways, and he made no effort to set it up whatsoever. He played a few tracks for us casually, probably thinking that these poor students were just wasting his time. The turntable didn’t sound right to me, but my friend had already made his decision long before we set foot in the store. He was brainwashed by his hero Ivor to think that even a poorly set up Linn Sondek was better than anything else out there.

After I started working, I was able to save up and buy something better. I sold my system to a friend and bought a Roksan Xerxes turntable with Artemis tonearm and Sumiko cartridge. I had a Musical Fidelity integrated driving a pair of Linn Tukan bookshelf speakers. These proved a considerable upgrade to the sound quality. I then got a job in the US and after moving there, I decided to buy some new amplification. The salesman at the secondhand shop convinced me that a tube preamp with a solid state power amp was the way to go, and I bought a Conrad-Johnson PV10 and an Aragon 2004. It was actually quite a nice combination, and sounded more musical than my previous integrated. I had a very busy job and soon got married, so there was no time to tinker. After 6 years, I returned home. Feeling more settled and with a more stable job, I became interested again in experimentation. It might be my early experience with the Quad ESL, or a romantic attachment to the golden years of high fidelity, I started looking into vintage gear. I studied circuits and learned all about vacuum tubes, transformers etc. I started looking through classified ads and secondhand shops. I bought several classic vintage amps including the Leak TL12.1, the Brook 12A, the Quad II, the Pye PF91, and the Telefunken V69a. I experimented with different passive components and tubes. Some I would restore and then sell, others I have kept. I also bought a pair of ESL57 while visiting my sister in Leicester. I came across an ad in the local paper and asked my sister to take me to see the seller. It turned out to be at a public housing estate and I managed to buy the pair for about 200 pounds. They needed a lot of work, but the exterior was in very good condition, which was exactly how I wanted it. Sending them home took more work, and I also ordered some new panels and EHT units from One Thing Audio. Over Easter holidays, I changed all the panels as well as the EHT unit and brought them up to spec. They sounded gorgeous with certain types of music, horrible with others. I tried driving them with different amplifiers. The Quad II was a bust. They sounded slow and anaemic. The TL12.1 were better; they sounded more transparent and lively, but bass was still lacking. The V69a were better still, giving the speakers more energy and better extension. The best match though was with my friend’s Mark Levinson ML2. With these amps, the speakers were transformed. Suddenly, the bass extension improved by at least one octave and sounded tuneful and solid. These speakers are fully capable of producing fairly deep bass, but most amplifiers cannot cope with the high impedance at these frequencies. It is probably a sacrilege to some people to drive the ESL57 with solid state amplification, but it works. Another idea came from Tim de Paravicini, which is to drive the panels directly with output tubes, which is not a bad idea considering that the output transformers are usually the most expensive components in a tube amp. I never got around to experimenting with this, since the memory of my physics teacher was still haunting me.

After a couple of years in Hong Kong, my turntable gave up the ghost. Probably due to the humidity, the subchassis warped. It was apparently a common problem with the early Roksan turntables. I was becoming intrigued by idler wheel turntables anyway, so I bought a Garrard 301. It had a grease bearing, and came with a slate plinth, an SME 3012 S2 tonearm and a fairly new Clearaudio cartridge. The whole package was ₤1000 from a secondhand shop in London, and as I did not like the cartridge, I sold it on Ebay. Over time, I have changed the main bearing and the tonearm bearing, rewired the tonearm and changed the arm base. The idea was to correct the weaknesses of these vintage components while preserving the characters made them great.

On the electronics front, in my quest to learn about tube circuits, I befriended Allen Wright of Vacuum State Electronics. Allen had his firmly held beliefs on circuit design, based on sound engineering principles and impervious to trends and fashion. I became his “beta tester” for his RTP-3 preamp. During this two year period of experimentation, when I built the preamp by point to point wiring, much was learnt about circuit topology, components, and the relationship between measurements and sound quality. We ended up with a superb sounding preamp that has won much critical acclaim. This was followed by the differential 300B power amps. Having worked with these amps, which use tubes for signal amplification and transistors as regulators and current sinks, one can appreciate that each kind of technology has its place. Each type of device has its advantages, which should be exploited to the full in a circuit. The criticism directed at tubes of being “soft”, “coloured” or warm sounding is not due to the inherent characteristics of these devices, but the way the circuits were designed. With proper implementation, tube amps can sound as dynamic, neutral, extended and speedy as their transistor counterparts.

I moved into my current home 10 years ago. As the flat needed to be completely renovated before I moved in anyway, I asked an acoustic architect friend to design the living room. He was more used to designing concert halls and music studios, but he obliged. The journey was another wonderful learning experience. He did a superb job, and it is an example of how one can marry good acoustics to an aesthetically pleasing living environment. Unfortunately, the living room has outgrown the Quads. The much larger space, coupled with the acoustic treatment, meant that the Quads were not able to produce enough sound pressure. I was sad to see them go, but this also presented me with an opportunity to experiment with horns, something I had always wanted to do. I have had some experience with different horn components, having listened to various vintage speakers, mainly Western Electric, Altec and JBL. After evaluating different drivers and horns, I decided to use the wonderful Electrovoice T350 tweeters, JBL 2450H mid-range compression drivers with 500Hz rectangular wood exponential horns and Altec 515C bass drivers in reflex cabs. Frequency divider duty is relegated to an Accuphase F25 analogue active crossover. A pair of Townshend ribbon supertweeters add some airiness at the top end. The horn drivers, with their 110dB sensitivity, are merciless in revealing any shortcomings and a very useful tool for reviewing components.

Today, I am still experimenting. With our hobby, the possibilities are endless. A high sensitivity horn system is like a microscope, and faults become very obvious. This could be frustrating and yet exhilarating when progress is made. I have experimented with making interconnects and speaker cables, which are finally getting to the point of being acceptable. There is still much to do, and I will share my experience here during this unending quest for perfection.

Analogue: Garrard 301/SME 3012-S2/Ikeda 9TT, Nagra T Audio tape recorder, Nagra IV-S tape recorder.

Digital: Lampizator Level 4 DSD DAC, Microrendu, MacBook Pro with Audirvana Plus v.3, Tascam DA-3000 Stereo Master Recorder.

Preamp: King/Cello tape preamp, Vacuum State Audio RTP-3D.

Crossover: Accuphase F25

Amplifiers: Vacuum State DPA-300B, Mark Levinson ML27.5

Speakers: Altec 515C (below 500Hz), JBL 2450J (500-3500Hz), EV T350 (above 3500Hz),