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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc.

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Old 3rd Dec 2019, 12:02 am   #21
jamesperrett
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Default Re: Nakamichi bliss!

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Back in the day, I was told that cassettes were better than open reel, because they had Dolby, 'metal tape', and all sorts of things.
Of course in the professional world there was Dolby A and then Dolby SR which were more sophisticated than the Dolby B, C and S that were used domestically. Tape formulations also improved in a different way, generally targeting higher output where reference levels could be up to 9dB higher than with older formulations.
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Old 3rd Dec 2019, 12:07 am   #22
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There tends to be an audible 'crushing' effect with cassette recordings that you don't get with R2R, though there is a lot of variation between different tape stocks even on the same machine. I assume it's a combination of slow tape speed, thin oxide coating and narrow track width.
Have you ever wondered why the frequency response of a cassette deck is normally quoted at -20dB relative to 200nWb/m? If you look at the response at 0dB it would look terrible with the high end drooping considerably. Cassettes can easily be driven into saturation at high frequencies.
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Old 3rd Dec 2019, 2:19 am   #23
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Default Re: Nakamichi bliss!

Like someone said about tuning engines, 'there's no substitute for cubic inches'
With tape, it's square metres per second. Anything that can be done to tart up a small format can be applied to a larger format, if there is any need.

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Old 3rd Dec 2019, 6:20 am   #24
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Default Re: Nakamichi bliss!

That's true. The specific need to record at 20db below reference was usually to avoid HF saturation and the misleading frequency response results that gave.
That was much more of a problem with slow speed recordings of which cassettes were an example. Open reel tapes at the same slow speeds had the same problem.

For cassettes, Chrome and then Metal came along which performed better than Ferric specially in the HF MOL saturation area. My 90's TDK tape reference book states detailed performance figures for their range of tapes at that time. MOL (saturation output level) at 10Khz for their TDK D tape was -8.5db and for Metal -1.0db ( both re 250nWb/m)

Many Tascam Portastudio decks performed quite well in the HF saturation department. They used double cassette speed (3.75ips) and "Chrome" (Type 2) tapes.
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Old 3rd Dec 2019, 7:43 am   #25
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Default Re: Nakamichi bliss!

It wasn't just the tape, the pole tips of recording heads could go too vlose to saturation and there was a compromise between hardness for wear versus saturation level of the pole material.

At higher tape speeds, on open reel machines there was also the opposite problem of engineering a long enough pole piece contact with the tape to get good LF response. There are two sampling aperture effects, the distance across the gap and the contact length of the pole pieces.

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Old 3rd Dec 2019, 4:07 pm   #26
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Default Re: Nakamichi bliss!

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With tape, it's square metres per second.
Or square metres per fortnight, if you don't like small numbers
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Old 4th Dec 2019, 12:28 am   #27
TIMTAPE
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It wasn't just the tape, the pole tips of recording heads could go too vlose to saturation and there was a compromise between hardness for wear versus saturation level of the pole material...
True, and some manufacturers like Nakamichi and Revox chose to stay with the softer head pole pieces for better fidelity even if it meant somewhat greater head wear.

This relates to Nakamichi's "pressure pad lifter" on its dual capstan decks. With the pressure pad now out of the way, the Nak heads wore more evenly and lasted considerably longer before head relap or replacement was needed. A pressure pad, especially when caked with tape muck can prematurely ruin a tape head. No surprise better designed open reel tape machines did away with the pressure pads, at least when the manufacture of tapes was improved to the point that omitting the pad was possible.

As far as I know though, Nakamichi was the only company to use the pressure pad lifter on cassette decks.

Interestingly, one company that I know of, Tandberg, used a softer material for the record head, but a hard Ferrite head for the repro head. I think I saw this on the TD20A model.
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Old 4th Dec 2019, 8:13 am   #28
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Default Re: Nakamichi bliss!

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As far as I know though, Nakamichi was the only company to use the pressure pad lifter on cassette decks.
Agreed. I can't work out why Revox didn't do the same, given the quality of their dual capstan transport. Perhaps the head profile had something to do with it - they bought theirs in from Sony, I think.
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Old 4th Dec 2019, 10:55 am   #29
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As far as I know though, Nakamichi was the only company to use the pressure pad lifter on cassette decks.
Agreed. I can't work out why Revox didn't do the same, given the quality of their dual capstan transport. Perhaps the head profile had something to do with it - they bought theirs in from Sony, I think.
Interesting. Yes I believe that machine was the first cassette deck Revox made, so not surprised if certain parts were sourced elsewhere. I'd thought not using the pad lifter might have been to do with Nak having copyrighted it.
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