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A Love of Music? or Sound?

By Frank Greenhalgh

It was the summer of 1956. I had finally put together what I thought was a real "Hi Fidelity" system. I was very excited as I put my brand new copy of "My Fair Lady" on the VM record player and set the speed to 33 rpm and the GE cartridge to LP (as opposed to 78). As the arm was lowered to the record and the needle with its 15 grams of weight settled in the overture started playing. I adjusted the volume on the preamplifier and marveled at how wonderful it was to be able to hear the music as if you were there, at least that's what I thought. I didn't realize how much improvement would appear in the next decades. How could I have imagined that a laser would replace the needle, and the analog audio track would become a series of ones and zeros. Not only that but in stereo!

The system was totally Heathkit. I had built each component with painstaking care, the three-tube preamplifier, the six tube FM tuner and the 35 watt Williamson amplifier using a matched pair of Mullard EL-34 valves. I even had Heathkit speakers. A 15" woofer, 8" mid range, 4"horn tweeter and a super tweeter, mounted in two enclosures. Heath supplied the enclosure wood, pre-cut with the holes drilled. You took the bag of screws and the white glue (supplied) and screwed it together yourself. It was a ported enclosure and even with the 15" woofer it did not really have any low end below 60hz. Such was the state of the art in 1956. Still it was the best I had heard and brought me many hours of listening pleasure. High quality sound was just getting underway.

Over the years the ability to reproduce sound accurately has become a commodity. Today speaker design and testing are all done with computers. Thanks to people like Teil and Small it is possible to optimize the size of speaker enclosures and still maintain a tight and accurate bass. Tweeter designs also have improved due to viscous cooling and heat sinking. Crossover designs can be optimized to maintain accurate phase information. Good audio is everywhere. Today, automobiles boast hundreds of watts of amplified audio using up to ten speakers. Digitally controlled algorithms can make your home theatre sound like you're in a stadium or a jazz club. "Commodity sound" is so good that it no longer is any fun to be an audiophile. I used to be one, or at least pretended to be one. Audiophiles are sort of strange people relatively speaking. They love to listen to music reproduction that is far above the world of "Commodity sound". Audiophiles tend to also prefer the sound of tube amplifiers to transistor amplifiers. They prefer listening to 331/3 rpm vinyl records than to CDs. Many audiophiles will tell you that the sound obtained using the pure analog equipment of a decade ago is far superior to what is selling in your local Circuit City. Are they right? Let's see.

Analog vs. Digital Recordings

One of the reasons I left being an audiophile was the fact that I had to replace my needle in the phono cartridge very often if I wanted to maintain the highest quality. This would drive me nuts because needles were expensive and one slip and they are gone. When I heard about CDs, I thought, "my prayers have been answered". I rushed to a Stereo Store to hear the sound of the new CDs. It was very disappointing. One of the things that any audiophile wants to hear is called imaging or presence. If you are listening to a stereo recording of a string quartet or a Dixieland band over a good stereo system in a large room, you should be able to place the sound of each instrument on a sound stage formed between the two speakers. It is this presence effect that brings the realism to the discerning listener. The early CDs lacked even a hint of presence. The reason was phase coherence. Specifications for audio equipment generally deal in power, frequency response and distortion. Nowhere will you see a phase coherence specification on a system. Especially between the left and right channels.Yet this is the true measurement of a system's ability to sound alive. Tests on human hearing have shown that we depend on our ears to determine the direction of a sound source using the phase difference between each ear. This phase difference is the measure of time difference it takes for a point source to reach each ear. Early CD technology did not take that into consideration. Eventually CDs have improved this by using multiple sampling techniques and better A-D and D-A converters. Still the CD probably does not stand up to a good analog recording regarding imaging. So maybe the audiophiles are right. I think it is a judgement call. The decrease in spatial imaging is offset by the 90 db noise floor and dynamic response that CDs have. I would like to compare a CD to a good quality record on my system but my turntable needs a new needle.

Transistors versus Tubes

A true engineer will argue that if both amplifiers meet the same distortion and frequency response specifications the sound should be identical. Maybe, but why do these people tell us that tubes are superior. The audiophiles have support in this field for tube preamplifiers. The recording industry's golden eared recording engineers prefer tube preamplifiers for vocals and stringed instruments. Any recording studio will have tube preamps to warm up a vocal. There is the answer "warm up" the vocals. What tube amplifiers do is change the sound to a warmer one. How is this done? One thing I always noticed on tube versus transistor amplifiers is when they are overdriven the waveforms are entirely different. If you picture a sine wave growing in amplitude until the top and bottom are clipped that is the transistor amplifier. On a tube amplifier the sine wave stops growing higher and becomes fatter. Maybe that fatness sounds warm. But you say, "Why don't they sound the same when they're not overdriven? Well another theory is that tube amplifiers have very little feedback, depending on an extremely linear design to maintain quality. Transistor amplifiers use huge amounts of feedback. Audiophiles claim that large feedback causes transient inter-modulation distortion. When the signal changes rapidly they say that the feedback causes hunting as it corrects and it is this hunting that is heard as coldness when using a transistor amplifier. Could be.

Some things you miss

I know one thing, I do not miss the times when a line frequency hum came into the system due to filament leakage in a tube. Nor do I miss the problem of microphonic tubes ringing when you place something near the preamp. I certainly don't miss the low rumble when acoustical feedback occurs when the needle acts like a microphone at high volumes. I hated replacing needles and hearing pops and scratches due to static electricity and mishandling. Yet I hold a fond spot in my heart for the times I would sit in absolute awe listening just listening. I could pick out the placement of the Cymbal and the Bell on the sound stage. You could taste the resin of the violin strings. Realism in sound. Those days have gone for me. I have two hundred CDs in my player and I just enjoy the music and not so much the sound.

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