Sony TC-388-4 1/4" tape question

[tester333]

Newbie question here. My Sony TC-388-4 has a "Tape Select" switch that toggles either "Normal" or "Special". I assume that the "Special" position is for use with tape that has a specific amount of oxide-coating. Question is exactly how much oxide-coating would be appropriate for use in the "Special" switch position? For example, Quantegy 456 tape has 500u oxide-coating, 499 tape has 600u, and GP9 tape has 700u. Am I correct to assume that the "Special" switch position is suitable for each of these tapes?
Many thanks.

 

[surroundophile]

I have a Sony TC-854-4, which also has this switch. It was intended for tapes that were "Low Noise-High Output", requiring a different bias, such as Sony's "SLH" -prefixed tapes. I imagine any other low noise-high output tape would work, although the biasing may be a little off.

 

[tester333]

Thanks, surroundophile. I'll search for info on the Sony "SLH" prefixed tape. I guess Sony no longer makes this tape?

 

[QuadraTOMic]

The GP9 may be too hot a tape for your deck. If you're thinking about getting some, it's not worth the extra cost.

 

[tester333]

Thanks, QuadraTOMic. I've found someone who is selling 5 reels of Sony SLH-180 that already have recordings on them. Question--are these tapes too old to be of any value/use? I would imagine that the oxide has deteriorated. Thanks much.

 

[timbre4]

Maxell reels hold up very over the years; there are a couple formulations that would probably match the bias/EQ options you have to choose from.

 

[surroundophile]

Thanks, QuadraTOMic. I've found someone who is selling 5 reels of Sony SLH-180 that already have recordings on them. Question--are these tapes too old to be of any value/use? I would imagine that the oxide has deteriorated. Thanks much.

I have some of the SLH tape I bought and recorded in the 70's. The tape is still good, and plays back fine. As long as it was kept at room temperaure & humidity.
I've often wondered about the record labels complaining about masters gone bad and having to bake them for one last play. My tapes from the 70's are fine. I even have some tapes (of a different brand & bias) from the 60's that are fine.

 

[Philip Spinner]

Do tapes need to be exercised periodically to prevent print through or is this bull. I ask because I have many Ampex quad reels that are still factory sealed and haven't seen the light of day for over 30 years. Could the damage already have been done.

 

[tester333]

Good question, Spinner. I think the "print through" phenomenon is basically the result of "gravity"--as it pertains to tape that has recordings on each side--i.e. 4-track cassette. Somehow, I doubt that tape that only has recordings on one side (i.e. 4-track rtr) would be susceptible to this. I'm only basing this opinion on my limited understanding of the "physics" involved. It would seem to me that, because "tape" is basically non-porous, simple gravity does not produce enough force to actually push recorded info thru the tape--thus allowing it to settle where it may. Of course, I'm no expert. Hopefully, someone with more experience will come along and have a better answer. Thanks.

 

[ClarkNovak]

Print-through is a function of the coercivity of the specific oxide formula, and to some degree the thickness of the Mylar backer. Good-quality (by which I mean name-brand - 3M, TDK Mastering Series, etc.) 1.0 - 1.5 mil tape very rarely prints through, while 0.5 mil and bulk no-name stock will do it nearly every time.

The tightness of wind on the tape pack can also have an effect - pro-grade decks were calibrated to wind tape to a "loose" pack, while most low-end home units just wound it up as tight as could be.