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Re: [ARSCLIST] cassette crackle

Steven C. Barr <stevenc@xxxxxxxxxxxxxx> wrote:
I actually used a similar approach to put as many 78's as possible onto a (theoretically) "stereo" reel-to-reel tape...! The first bunch put the mono signal onto the, say, Left, channel of the tape, by feeding the mono signal only into that channel input. The second bunch did the same, with the tape reversed (track 2?).

Actually track four.

Then repeat both processes, except plug the mono signal into the Right channel. Result...?! Four separate tracks full of mono 78's on one r2r reel of tape!

If you read the instruction book, this is the way you were SUPPOSED to record mono on quarter track machines.

Randy Watts wrote:

> Most old radio collectors who used the open reel format made their tapes this way. It was more economical, and it obviously meant you only had to store half as many reels of tape, but long-term, there was always a high risk of bleed-thru becoming a problem.

Part of the problem is that quarter track open-reel tracks are interlaced. Left is track one, Right is track three. So you record first on left and get tracks one then four, then switch over to the lower track and record tracks three then two. When the configuration was designed in 1957, head manufacturing required a certain amount of insulation between adjacent tracks, which is also why the guard-band is wider in half track stereo than half track mono. By the time Phillips brought out the cassette, head manufacturing had improved to allow adjacent stereo tracks

> > Of course, one didn't want to play this result back in stereo...?! Steven C. Barr

It is also why Phillips built into its licensing rules a prohibition against building machines that could record channels one-at-a-time. Their philosophy was that every machine could play every cassette. Since the stereo tracks were adjacent, they could be played together on a mono machine, and a stereo machine could play a mono tape and have the audio come thru both tracks. That was also why all cassette machines were single speed, 1 7/8 IPS, so there would be no confusion.

Of course the Library of Congress objected and told Phillips they wanted to record four separate mono tracks at half speed. Phillips said no. Then LC said, we are the Library of CONGRESS, and you are a foreign company. If you wish to continue to do business in the U.S. you will let the Library of CONGRESS make dual speed machines with four independent tracks.

The reason why Nakamici was able to build machines with 3 3/4 speed was because the patents were about to expire and they never bothered taking out a license to build those models. When the patents expired EVERYBODY was freely able to make recording studio type machines with multi-speed and multi-track capability since licenses were no longer required.

Mike Biel mbiel@xxxxxxxxx

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