President's Message
February 2003

1. A class action suit filed on behalf of CD purchasers from 1995 to 2000 has been settled with a pay out that is to be distributed in equal shares among people who purchased at least one CD from a retailer in that period. Payment is in the range from $5 to $20 and you do not need proof of purchase. If the amount is less than $5, it will be given to charity. Deadline is March 3. To apply, fill out a simple form at

2. All CD players have muting circuits to prevent nasty noises as the circuitry is acquiring the digital data stream. The beginning of a CD allows 2 seconds for this; each track has a .3 sec "un-mute" time allowed in the original specification. Usually this doesn't matter--for my work I generally allow 1 second between the track time and the beginning of the music which gives a more natural sound.

However if the music is continuous a shorter gap may be appropriate. I recently had a client who wanted the track to start as close as possible to a particular note--he didn't want to hear the decay of reverb from the previous note. I put the track .3 sec before the note, but wondered what was the actual acquisition time. To investigate I made a special CD with 16 tracks, each starting at a precise minute, i.e. 2 minutes, 3 minutes and so on. Then I placed a 1 msec pulse at full amplitude a specific distance from each track time. One minute, .35 seconds; 2 minutes, .30 seconds; 3 minutes, .25 seconds and so on to 15 minutes, -.6 seconds.

By playing this disc, searching for each track, and noting at which track the pulse disappeared, I could tell at what point in time the CD player was acquiring the music. The results were surprising: all of my 3 players cued exactly at the track location. So no margin of safety is needed. I plan to test some more players to get a wider sample.

3. Under the header "Rediscovering a Secret of 60's Sound: Vacuum Tubes", Roy Furchgott reports on the continuing fascination with tube technology. The prevailing but highly arguable theory is that while all stereo components introduce distortion, tube circuit distortion is itself musical. "Vacuum tube circuits produce almost exclusively even-order distortion," said Lou Johnson, a partner in Conrad Johnson Design, a company in Fairfax VA, that manufactures both tube and solid state components. "These tones are essentially one octave apart." So tube distortion is basically in pleasant harmony. "A traditional transistor circuit produces odd-order distortion, so it tends to be discordant," he said. [Sounds plausible but not really so. Almost all tube amps use push-pull output stages to cancel even order distortion, so like transistor amps they have both even and odd order distortion, just lots more at high levels].

Solid state fans say that while tubes may add pleasant inaccuracies, they are still inaccurate. "Music isn't always pleasant, lush or velvety, or the other things attributed to tubes--sometimes it's harsh," said Bill McKiegan, VP for sales and manufacturing at Krell Industries. Krell is so dedicated to reproducing unaltered sound that it provides no treble or base [sic] controls on its gear. [NYT 19De03]

David Hadaway

President, Boston Audio Society


The Boston Audio Society
PO BOX 260211
Boston MA 02126

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updated 11/11/04