From: utzoo!decvax!harpo!eagle!mhtsa!alice!rabbit!wildman Newsgroups: net.audio Title: Re: Pinch rollers and biasing Article-I.D.: rabbit.169 Posted: Wed Jan 7 16:46:07 1983 Received: Sat Jan 8 04:49:40 1983 References: rocheste.364 Mark was right-- I did leave one thing out of my last note. The record-on/record-off transient also can cause quite a bit of head magnitization if the head isn't coupled through a transformer(the usual case). The startup and shutdown of the erase oscillator were not carefully considered until a few years ago in consumer machines, much to some pro's distress. The startup transient, whether from power on or record on, is still the primary cause now-a-days. While it IS somewhat machine dependant, it takes place to some extent on all machines, even (and, in fact, due to the dircuitry required for better performance , to a greater extent) the best of the bunch. (Direct coupled head amps have to do something with the bias current...) All decks do do it though, at least to some extent. I am not aware of any that have a really bad time of it, but I deal mostly with higher end decks (Lowest is something like Teac V7 or so, a nice machine) and may not enounter it often. I do demagnitize all of my decks regularly, with the power off, and with a line-supplied demagnitizer with a *LONG* snout. I also use iso-propyl on the heads, and freon TF on the rubber parts. (Yes, by ALL means keep it out of bearings!) P.S. Mark--I didn't mean you-- Look around this newsgroup.