A message from the Designer
My analog experience transitioned from hobbyist to professional with the design of the ARP 2600 Music Synthesizer
( made into a legend by Stevie Wonder) in 1971. Since 1996 I've been writing component design articles and reviewing speakers for Audio Xpress magazine. The June '06 issue shows "Mad Katy", the perfectionist 250 watt tube amp I designed. One year later ( June '07 issue), i described how Intrinsic Fidelity Testing allows direct listening comparison of a component's input and output signals, with the highest resolution and freedom from extraneous variables.
What is Analog?
Analog simply mean continuous, not made of pieces. When you hear a sound, or smell a rose, or see the color yellow, the sensation is of such a nature. Sound waves, and the electrical voltage from a recording microphone, are analog.
In digital recording, such as on CDs and DVDs, the microphone voltage
( called the audio sign
al) is periodically sampled (at a 44 KHz rate for CDs); then each sampled signal point is stored as a number (a group of digital bits). Signal point is stored as a number (a group of digital bits). Each bit is binary; that is, it can only be on or off. 16 such bits are used in CDs. This allows 65,536 signal levels to be captured for each sample.
When CDs were first introduced to the market, they were touted as having "perfect sound forever". But now, discriminating audiophiles know better! And researchers have shown that the human hearing system can respond to much more than 65,536 signal levels. In addition, although a good CD player can reproduce the digital bit numbers without errors, the recording and playback processes are degraded by high-speed timing errors, called jitter.
SACDs (super audio CDs) are much better than standard CDS. But many believe that vinyl records are capable of the highest quality sound - witness not only the resurgence of vinyl into the audiophile community (and even, to some extent, the general music market). Also noteworthy is the proliferation of new, high quality turntables, cartridges, and phono preamps. Why? It is not, as some cynics say, simply nostalgic. It's because the vinyl record is pure analog. No breaking of the signal into digits. Even though records are subject to wear and surface scratches, most audiophiles agree that the sound has an immediacy, fullness, and depth that sounds more natural, more involving like live music, than any digital system. Recent research has even shown that digitally recorded music induces listener stress and fatigue after long periods. If you listen to a good vinyl recording of an orchestral string section, the sound can be described as a smooth "ocean" of beautiful violin tones. But if you immediately listen to the same performance on a CD, the sound becomes synthetically "blended", as though the violin tones were lightly "sandpapered".
To be technically complete, all physical phenomena are believed by physicists to be "digital"; that is, composed of fundamental units called quanta. But there are more of these quantum "bits" in one brain cell than there are digital bits in all the CDs in the world! With such astronomically large number of "natures bits" existing even in tiny sensory stimuli, we perceive an unbroken analog wholeness in our sensations. And believe it or nor, a healthy dark-adapted eye can see individual photons
(a photon is a quantum of light); and a good ear comes close in sensitivity.
Even with CD playback, the quality of your analog components (such as the power amplifiers) is important. There are some "digital" (high-frequency switching Class D) amplifiers on the market, but sensitive and experienced listeners again prefer the best analog components.
An analog component ( phono preamp, line stage, power amp, etc.) has a difficult job. It must, as faithfully as possible, transmit audio signals with (sometimes) a dynamic range of 100dB. That's a power range of 10 billion to one! This would be like being able to control your car's 200 hp engine to within one 50 millionth of a horsepower!
Conclusion:
With good vinyl and SACD recordings, the design of analog playback components can be extremely demanding. Maintaining the highest transparency (signal fidelity) becomes even more important as better recordings, players, and loudspeakers are continually developed.
Hard to find articles by author:
SONIC COMPARISON OF POWER AMPLIFIER OUTPUT VS INPUT
This simple test method is "beyond compare" in determining a power amp`s I/O signal. By Dennis Colin
A 6-CHANNEL VOLUME/BALANCE CONTROL
Construct this master volume control to experience the excitement of "better than CD" quality by Dennis Colin