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    A Tale of Two Different Systems

    Issue 153

    I was recently asked by two friends (independently of one another) to help them build their new audio systems.

    Other than replacing my phono cartridge with another of the same model recently, I have not bought a new piece of hi-fi equipment since buying my current DAC about seven years ago. Not having kept up with reviews of new equipment, I am quite outdated on what is available on the market. I have therefore subscribed to The Absolute Sound and Stereophile in a bid to brush up on my knowledge.

    To help my friends with their systems, I had to first understand their needs. My old friend Freddie is getting ready for his retirement two years from now. He just bought a house, and is currently planning its renovation. He wants to have a dedicated room for music and movies, and prudently decided to incorporate acoustic treatment during the renovation. To make life more difficult for me, Freddie’s wife is one of the most popular pop/folk singers of her generation in Hong Kong; if you have ever watched some of the Hong Kong TV series from the 1970s and 1980s and are familiar with the theme songs, you would know her voice. Freddie himself is highly knowledgeable in Cantonese opera. He is also getting into classical music, especially large-scale orchestral masterpieces. He has been using CD as his main source for the past three decades, but he had also wisely put all his LPs into storage (rather than getting rid of them), and he now wants to get back into vinyl playback. He initially reached out to a friend who distributes several extremely exotic brands of high-end equipment. However, after visiting his friend’s showroom several times, he became utterly confounded. He told me he found the sound very unnatural, and could not relate to the price tags at all. In fact, he listened to a recording of a famous Cantonese opera singer, and did not even recognize her voice, even though he had known her personally for more than three decades!

    Freddie is currently using a pair of Magico S5 loudspeakers, which he drives with a Gryphon integrated amplifier. The Magico speakers have a claimed sensitivity of 88 dB at 2.83V, but having a nominal 4-ohm impedance, the figure is in reality 85 dB at 1W. Even though the Gryphon is rated at 600 watts into 4 ohms, he notices that the soundstage collapses during loud and complex orchestral passages. I get the feeling that Freddie places more emphasis on the visceral aspects of the sound, such as the dynamics, soundstage, imaging and transparency. After listening to my horn setup, he decided that he wants a system that can get close to life-like dynamics.

     

    Magico S5 loudspeakers.

    Magico S5 loudspeakers.

     

    Those of you who have read my previous articles should know by now that I am quite opinionated on the best way to achieve good sound. I count dynamics and tonal balance as the two most important qualities. I strongly believe that in order to achieve anything that remotely resembles real-world dynamics, one needs to have sensitive speakers. Here, I am talking about a minimum sensitivity of 95 dB/1W/1m, and preferably greater than 100dB. Some people will argue that power comes cheap nowadays. However, driving insensitive (inefficient) speakers with powerful amplifiers comes with its own set of problems. Most inefficient speakers usually have rather nasty impedance curves, which means merely looking at amplifier power output figures would not account for how well an amplifier can drive such speakers.

    Also, high power means increased heat dissipation at a loudspeaker driver’s voice coil, and the associated rise in temperature will result in thermal compression. Amplifier distortion levels also go up as power output increases. Furthermore, high-power amplifiers often employ parallel output devices, and it is difficult to find perfectly matched transistors or tubes. Any mismatch will again increase distortion. High-quality, high-power amplifiers are therefore expensive. With high-sensitivity speakers, on the other hand, an amplifier can stay in Class A operation most if not all of the time. Efficient driver designs such as compression drivers have much smaller diaphragm excursions, thus lowering driver distortion by an order of magnitude, and they also have a much faster transient response. I also strongly believe in doing away with passive crossovers. These networks complicate the impedance behavior, reduce power efficiency, and invariably muddy the sound even if they make use of very high-quality components.

    Freddie had spent a significant sum on his Magico speakers not so long ago, and he also likes their character. He is therefore reluctant to change them. He is keen to find an amplifier that will transform the sound of the speakers. He went back to the dealer who sold him the system, and the dealer recommended auditioning a pair of monoblocks from Constellation Audio. My friend was indeed very impressed with the sound, until he found out how much the amplifiers cost and almost fell out of his chair. At least, he now knows what his speakers are capable of.

    I took Freddie to visit my friend Edward at his showroom. I remember hearing Edward’s setup at this summer’s Hong Kong high-end audio show and came away mightily impressed. He had a pair of Kaiser Acoustics loudspeakers driven by Kondo tube electronics. He actually sold that pair of speakers at the show, and in any case, the cost of this setup is, shall we say, slightly out of our price range. Edward promised that he would put something together appropriate to Freddie’s needs. Two weeks later, we went back to the showroom. Since Freddie wanted to buy a record player, Edward had set up the SME Synergy, which is an integrated package of turntable, tonearm (SME IV), cartridge (Ortofon MC Windfeld Ti) and phono preamplifier (designed by Nagra). Since I am a fan of SME (3012 tonearm), Ortofon (SPU Classic) and Nagra (IV-S and T-Audio tape machines), this sounded very exciting to me. The record player has the legendary SME build quality: smooth, solid, no-nonsense, form follows function.

    SME Synergy turntable system.

    SME Synergy turntable system.

     

    Amplification duty was fulfilled by a preamp and stereo power amplifier from YS Sound of Japan, driving a pair of Zellaton Plural EVO speakers. While the speakers are comparable to Freddie’s Magico, the amplifiers are even more expensive than the Constellation. Edward also had a surprise for us. He did not recognize Freddie’s wife during our first meeting, since everyone was masked. However, he soon figured it out after we left. He pulled out an LP of the first commercial recording she made, at the age of 16! This was well before she became famous, and few people even know this record exists. The sound quality of the LP was, to put it politely, serviceable. We listened to a range of recordings including large orchestral works, vocal, jazz, and some classic rock. The record player acquitted itself well. It has good pitch stability and dynamics. It doesn’t quite achieve the transient attack of my modified Garrard 301, but nonetheless, it sounds solid and rhythmic. Most importantly, it does not blur the leading edge of notes or have audible wow on piano music like many belt-drive tables. It sensibly uses a very short rubber belt between the motor pulley and the sub-platter, minimizing the stretching of the belt while maintaining a tight coupling. I thought the whole package represented excellent value for the sound and the build quality.

    I told Freddie that the best course of action would be to wait until his music room is ready, and I will then arrange the loan of several amplifiers for home auditioning. I suspect the top-end amplifiers from manufacturers such as Parasound and Bryston, known for their excellent price/performance ratios, will fulfill Freddie’s requirement. There might perhaps be other tweaks that we can employ to improve the sound without having to change the amplifier.

    Beatrice is a family friend going back to my school days. She was in fact my older sister’s classmate. She is a very knowledgeable enthusiast of jazz and classical music. She too has just bought a new flat, which she is currently renovating. The living room will be much more spacious than her current abode, and she is keen to acquire a new music system. I tried to persuade her to include acoustic treatment in her architectural plan, and even introduced her to my friend James the architectural acoustics expert. However, she is resistant to the idea of spoiling the aesthetics of the living room in order to improve the sound. I will therefore wait until the room is ready, and then try to correct any potential problems in ways that are aesthetically acceptable. Her current system is comprised of an early Quad CD player, 44 preamplifier and 405 amplifier, and a pair of Rogers LS3/5a speakers, which her brother bought for her once upon a time. I told her that the electronics are not worth keeping, and she is better off with new floorstanding speakers, given the larger size of the new living room and the fact that she enjoys orchestral music. The LS3/5as are small enough to put into storage, and these speakers also fetch a pretty penny on the second-hand market in Hong Kong. She has a budget of HK$200,000 (US$25,000), and wants to continue to enjoy her large collection of CDs. From our conversations, I gather she places more emphasis on the tonality of the sound and its emotional impact on the listener.

     

    Rogers LS3/5a loudspeakers. There's a reason these have been around for a very long time.

    Rogers LS3/5a loudspeakers. There’s a reason these have been around for a very long time.

     

    Thinking that she is used to the classic British hi-fi sound, I took her to audition Tannoy speakers. The distributor’s showroom had a pair of Westminster Royal GR on demo, which were too large and too expensive for my friend. They also had a pair of Turnberry GR on demo, which we listened to. The speakers were driven by Esoteric amplifiers from Japan. The speakers each have a single 10-inch dual-concentric driver, which is the dual-concentric driver I prefer, finding the larger drivers too slow for my taste. My friend found the sound lacking in treble energy; and that the ambience of the acoustic space could have been better, and the soundstage was constricted and lacked depth. The driver sits too low for the typical seating height of a listener, and I suspect the off-axis response of the dome tweeter rolls off quite quickly. After tilting the speakers back, there was some improvement, but I still thought the high frequencies should have been better. The speakers are also quite polite in terms of dynamics. They sounded nice with chamber and vocal music, and were never strident, but their performance with orchestral music did not excite me. Worse still, the distributor did not have stock and estimated a waiting time of at least six months. Supply chain problems, apparently.

    I then remembered reading a review of a rather unusual speaker called the Zu Audio Soul VI. This company is based in Utah, and they produce high-sensitivity loudspeakers with full range drivers that do not employ passive crossovers. This immediately ticked several boxes on my list. They are also very reasonably priced, and their Hong Kong distributor is a well-established specialist in tube audio. I arranged an audition, and upon arrival at the shop, which is located in a grassroots district of Kowloon, we found ourselves in a showroom crammed full of a vast array of antique and modern tube equipment, as well as exotic NOS tubes in display cabinets.

    It turned out that they did not have the Soul VI, as it had only just been released. My friend, however spied a handsome pair of larger speakers in white at the back. They were the top of the range Definition IV, which the dealer was willing to sell at half price since a newer model would be arriving in the spring. Each speaker has two of Zu’s in-house designed 10-inch full range drivers, made of treated paper pulp. They are augmented by a horn tweeter based on the Radian 850 compression driver, and a 12-inch bottom-firing powered subwoofer. The level, corner frequency, phase and parametric EQ adjustments for the subwoofer are at the back of the speakers, allowing the user to tailor the bass response according to the room acoustics. The full-range drivers do not employ crossovers. The result is an 8-ohm speaker with a sensitivity of 101 dB/1W/1m and a very benign impedance curve.

     

    Zu Audio Definition IV loudspeakers.

    Zu Audio Definition IV loudspeakers.

     

    As my friend will continue to listen to CDs, an Audio Note UK CD player was used. We initially auditioned the speakers with the Rogue Audio Cronus Magnum III integrated amplifier, which uses push-pull KT90 beam tetrodes for output. My initial impression was not too positive, since the string tone did not sound right, and the amp was quickly changed to a Melody Marklos integrated amplifier using four 2A3 directly-heated triodes per channel in parallel push-pull configuration. The missing overtones of the strings were immediately restored, giving the sound more body. I was very surprised by how great the difference was between the two amps; the first amp made the string instruments sound hard and artificial, whereas the second amp restored the resonance of the sound box, giving the sound back its character and warmth. Similar to my horn speakers at home, these speakers magnify the most minute details. I suspect this might be due to the lack of a crossover and the high sensitivity of the drivers, allowing subtle differences to come through loud and clear.

    We then changed to an Audio Note UK Meishu Tonmeister single-ended 300B integrated amplifier. The sound took another leap forward. We could now hear the subtler dynamic changes, and the small inflections in the bowing of the strings and the shaping of the phrases. There was a spaciousness to the soundstage, and the music flowed with ease. The system gained the ability to make one think, even for a fleeting moment, that the performance was real. This is one of the few systems I have heard that make CDs sound great.

    Suitably impressed with this setup, we made another appointment for a re-audition two weeks later. This time, I brought some of my favorite demonstration LPs to play on the Nottingham Hyperspace turntable. This system sounded relaxed, and never gave an impression of being over-taxed even with highly dynamic large-scale orchestral music. The tone just sounded right, which is more than I can say for many high-end systems I have heard, regardless of their cost. You could tell a viola from a violin, and you would not confuse an oboe for a clarinet. Most importantly, the system could effectively convey the emotional impact of a performance. With the sound of this system, I found more similarities than differences to my system at home. My system also uses 300B triodes, but in a push-pull configuration. However, I use plasma tweeters and field coil drivers, and the cost of the raw drivers alone is more than what these Zu speakers cost at list price. And, I have to go to the trouble of using an electronic crossover and tri-amplification, with all the attendant complications. Of course, the Zu speakers do not reach the same level of dynamism as my speakers, nor do they have the same scale of presentation, but they are also physically a lot smaller. After two hours of listening, my friend took out her credit card and bought the system.

    The experience of the past two months has left me rather confused. I originally thought that it should not be difficult to help Freddie with his quest, given the much larger budget he has at his disposal. It turned out that his insistence in only looking at equipment with a high reputation amongst hi-fi reviewers has become a handicap. On the other hand, my friend Beatrice, who has absolutely no knowledge whatsoever of high-end audio, and who has never read a hi-fi magazine in her life, managed to find the perfect system for herself. This reminds me of a very wealthy friend who is an accomplished amateur cellist. He was the first in Hong Kong to buy a pair of the top model from a very well-known high-end loudspeaker brand. He later heard another pair of speakers at a friend’s place that cost about 1/50th of his speakers at home, and he was sufficiently impressed to buy a pair himself. He confessed to me that he normally listens to this pair of cheap(er) speakers, and only uses his expensive speakers when friends come to visit.

    Header image: Zellaton Plural EVO loudspeakers.

    6 comments on “A Tale of Two Different Systems”

    1. A guy I know has a pair of Magico S7’s & he’s driving them with a Constellation Stereo Hercules II & he’s very happy with the combination…just sayin’.

    2. Your friends are fortunate to have a knowledgeable, but not dictatorial, guide who really makes effort to understand what they want from their system and who is able to adapt to their wishes. They are also fortunate to have the opportunity for auditioning also, if I understand correctly, in the home. There are many of us who do not have access to auditioning – there are very few PS Audio’s that allow an in home trial period for remote users, where remote means in a Hi-Fi desert. For remote users the guidance provided by thoughtful reviews by “experts” is rather important, at least to narrow down the field. In my case I make the occasional odyssey to a Hi-Fi haven I(or heaven) and listen to many things in the store in one day, typically using my own source material. This is a very poor substitute for in home auditioning – just the fatigue factor alone impairs objective qualification. I am convinced that many expert reviewers in the well known magazines do suffer from a cluster effect where certain brands start off with a competitive advantage, while unknown ones suffer a competitive disadvantage.

    3. I enjoyed reading this!

      I am also a big advocate of high efficiency (100+ dB) horns, having designed a 4-way field coil system myself.

      I disagree on the crossover topic though: a well designed, simple, passive crossover will beat an active any day!

      1. Been there, done that, but arrived at a different conclusion. I like steep curves; 1st or 2nd order seem to have too much overlap. I prefer 4th order L-R, which is too difficult to implement with a passive crossover.

    4. Curious how you are implementing your active x-overs. I’m looking at building one of Nelson Pass’s analog crossover networks. I plan to extract the curves from my dunlavy crossovers with a function generator and scope as a starting point. My big question is if I can reproduce the phase and time coherence intrinsic to the original design. What testing apparatus would be needed? I’ve ordered a behrenger testing mic and preamp with usb out. Thanks Peter, Boulder CO.

      1. I was in an easier position since I started from scratch. I was able to do time alignment using the free Room Eq Wizard software. I swept each driver in turn, and on the impulse response, the software calculates the time delay, which is essential the time the sound takes from the driver to reach the microphone at the listening position. Alignment was simply moving the drivers back and forth relative to each other to obtain the same time delay. My speakers had three different enclosures for the three drivers, but if your speaker has a single enclosure, physical time alignment will not be possible. If you have the schematics for the crossover, you can see what type of curves it uses. For passive crossovers, the designer has to take into consideration interaction with the reactance of the drivers, which would not be necessary with the active crossover. You are better off experimenting yourself to see what kind of result you are happy with. Start with crossover points similar to what are implemented by the passive crossover. Borrow a digital crossover such as the Accuphase DF65, which is incredibly flexible. It can do phase alignment electronically. Once you have arrived at the optimum parameters, you can replicate it with the analogue crossover if you don’t want to stay in the digital domain.

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