Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!zaphod.mps.ohio-state.edu!wuarchive!uwm.edu!csd4.csd.uwm.edu!info-high-audio-request From: ogicse!agora.rain.com!david@uwm.UUCP (David Robinson) Newsgroups: rec.audio.high-end Subject: More from POSITIVE FEEDBACK (3/4) Message-ID: <8750@uwm.edu> Date: 8 Jan 91 14:49:34 GMT Sender: news@uwm.edu Lines: 110 Approved: tjk@csd4.csd.uwm.edu Originator: tjk@csd4.csd.uwm.edu The following article is from POSITIVE FEEDBACK, the newsletter of the Oregon Triode Society, and is Copyright 1990, all rights reserved. This article may be reposted or reprinted, as long as it is not resold, and as long as proper attribution of the source is made in full. Please keep this header in all copies made of this article. David W. Robinson Editor, POSITIVE FEEDBACK david@agora.rain.com ------------------------------------------------------------------------------ AUDIO TIPS John Pearsall As an installer who thought that he had seen everything, I can assure you I hadn't when I chanced to run up against a really intractable problem in Bellingham, WA, about a year ago. I had just installed a large mega-system with fine components, great interconnects, super speaker cable--the works. But we got a loud hum on all sources. I tried every ground loop solution that I knew, but to no avail. A frustrating four hours went into the detective work; it was definitely a 60 Hz hum, but from where? About the time that I was doubting my skill and sanity, the clouds parted and the gods smiled on me. The Perreaux tuner in this all-Perreaux system had a non-threaded coax connector, and the CATV (Cable Company) FM lead fell off. The hum stopped. Like a toothache that disappears, this brought comparable relief. I took out the meter and there it was: About 300 millivolts of raw AC coming in from the street pole, to be transferred to the chassis of the system. Six months later, I ran into a similar case in Tigard, OR, with about 180 millivolts on the lead. In both cases the cable guys were called and the problem was fixed in about ten minutes. Live and learn, huh? * * * Another subject: What does a crawlspace, garage, or unfinished basement have to do with the economics of installing a fine sound system? Here's what it can do for you if you have one of these under your listening room... ...what to do with wire is a bitch. It is always in the way. It is unsightly. It is expensive at best, and ridiculous when you have to go around the perimeter of the room. So--why not run it under your floor in the shortest and neatest fashion. Not only can you cut many feet off the cable cost, but it is so nice when the cable disappears from the living space. As in the usual case, plan very carefully, because splices are a no- no. * * * There is a good alternative to the above. Your amplifier(s) can be placed at the speaker end of the room if you can (A) get AC to them easily, and (B) drive long lines with your preamp output stage...that is, high current, low impedance out. They could be either balanced or unbalanced lines, but both are effective with the right driving source. And since only about 2 meters of speaker cable is needed, buy something really special. Now that mono- block amps are becoming more common, this drive scheme is probably ideal. Think about the concept a little for current or future equipment. * * * A better wire marking tag has shown up at the various retailers who sell bulk barrel food. It is like a bread tag, but is all white and has a 7/8" by 1 3/8" piece of card stock attached to it for writing. (I've found that a fine roller ball pen in black is best.) See if you can talk somebody out of a few dozen. * * * Do you want to de-gauss your moving magnet cartridge with a Flux-buster? Well, you can de-gauss the coil forms and pole-pieces in the body of the cartridge, but you must remove the stylus assembly so that you won't also de-gauss the tiny permanent magnet on the cantilever. As for MC cartridges: Just follow the directions, of course... * * * If you have a new Moving Coil cartridge, but lack the patience to break it in while having to listen to it, here's what I did. I mounted an Ortophon MC in a high quality, low mass arm on a Dual automatic. Using decent vinyl and turning it over fairly often, I put the 20+ hours on the cartridge in a few days of attended break-in. The Ortophon X3MC and the X5MC sound a bit strident until after at least 15 hours. However, I would suggest that you not break-in a really expensive coil in a real dog of an automatic. Make sure it is a pretty sophisticated one. If all else fails, go ahead and settle in the new cartridge the old way and just wait it out. * * * Now is the best time to tear the system down and clean everything. Use contact cleaner and carefully assemble or replace any nasty looking wire with the best you can afford. Now's the time to try the Tip-Toes, speaker spikes, damping feet, a new equipment stand, install a new FM antenna, special wire, AC line conditioning, buy a vinyl cleaning system, improve your storage for recordings and, in general, improve what you have for the indoor season. While you're at it, clean up that sloppy video system and enjoy a better picture, too. Wire quality makes a difference in video pictures and video recording quality, so invest a little money here, as well. That's all for this time--good listening.