More on Metropolis HERE, HEREHERE, HERE

More Fritz Lang info HERE

 

President's Message
October 2003

0.  We will be accepting nominations for officers at the October meeting. That's President, Corresponding Secretary, Membership Secretary, and Treasurer.

1.  "Noise and Moving-Magnet Cartridges" describes a circuit technique that achieves better noise performance in a phono preamp than has been achieved before. With moving-magnet cartridges, the limitation on the noise at high frequencies is that generated by the 47 kohm terminating resistor. This is the standard input resistance and cannot be changed. The author replaces it with a 1 megohm resistor and actively drives the end that would normally be grounded in order to simulate an input resistance of 47 kohm. The inductance of the cartridge shunts the noise of the 1 meg resistor so it doesn't appear. An improvement of about 3 dB is achieved. The article goes into great technical detail on the noise sources and their minimization and is highly recommended to phono preamp mavens. Electronics World Oc03.

2.  As a followup to last month's item "ASLSP", astronomers say they have heard the sound of a black hole singing. What it is singing, and perhaps has been singing for more than two billion years is B flat — a B flat 57 octaves below middle C. It appears as pressure waves through a hot thin gas that fills the Perseus cluster of galaxies 250 million light-years distant. The waves are 30,000 light years across and have a period of oscillation of 10 million years. "It's the longest lasting symphony we know of," said Dr. Bruce Margon, an astronomer at the Space Telescope Science Institute. NYT 16Se03

3.  In "News of the Sections" in the AES Journal, there is an unusually long writeup ( 2-1/2 pages) of a meeting of the Pacific Northwest Section, reminiscent of the detail and color of the better BASS writeups (I applaud this since the bulk of the journal is of little interest to me). It is about Greg Mackie and his audio companies ( Tapco, Audio Control, Mackie Designs) in the Pacific Northwest. One illustration: they liked the feel of the Alps pots, but couldn't afford the minimum order requirement, so they used cheap CTS pots. To get the viscous feel they tried STP, silicone heat sink grease, Crisco, and even raisin juice on the shaft. Finally someone came up with a compound that worked. Using it meant that they had to disasemble and reassemble each pot . Sometimes the compound got on the carbon element, causing clicks. Finally they hit on the idea of laying a bead of the compound around the shaft-bushing junction and heating the pot in an oven. Capillary action did the rest. Years later they discovered that the goo glued the polystyrene knobs to the shaft, making service a challenge. AESJ JL/AU03

David Hadaway

President, Boston Audio Society

email: dhad000@yahoo.com


 

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updated 11/11/04