I'm Confused on RMGI Tape pancake

[mpbird]

I hope this is a case of operator error. I bought a pancake of RMGI tape. I mounted it onto my empty metal 10.5 reel and went to thread it onto my RTR.

The tape is 'matte side' out. In other words when I thread it onto my RTR the 'shiny side' contacts the heads. This can't be right can it?

Thanks for your help.

 

[mpbird]

Nah, that's just not right. I rewound it and put the matte side where it belongs.

 

[dhnash]

What type of RMGI tape are you using? I know that the LPR-35 pancakes that I use have a brown (oxide) side and a dark gray (backcoating) side. The brown side needs to face the tape heads.

 

[mpbird]

Well there you go. Yes I have the LPR35-34530. I guess I'll turn it back around. Live long enough and you find out a bunch of things you didn't know. Thanks DH.

 

[Blue Shadow]

On back coated tapes the shiny side goes to the heads. Or non-back coated tapes, hard to tell...based on my limited experience.

I wouldn't ever think that a pancake was delivered inside out but it could be possible.

 

[mpbird]

Yeah Blue I think you're right. It was unwise of me to jump to the conclusion that it was inside out. Have to remember the manufacturer sells a lot of the stuff and probably knows what he's doing.

 

[KingBubba]

For studio engineers, tails out is the standard way to store tape. If you have ever heard a record where you heard to song start quietly before the song starts for real, this is caused by storing tapes with the lead out. The magnetic image bleeds through to the next layer of tape. Why this was done on blank tapes is a mystery. Maybe it was just due to habit.

 

[Skylab]

With blank tapes, there is no heads or tails Or put another way, it makes no difference, so the beginning of a blank tape is the head. And of course that has nothing to do with the recording side of the tape versus the non-recording side.

 

[Wilhem]

In the very, very old days, the recording side was wound to the outside. It was dull because it was an oxide coating, and the acetate backing was shiny. Different transport designs required the opposite winding: the dull oxide side was wound facing the center, inside the pack. As tapes developed, manufacturers began to calender or polish the surface of the oxide in order to increase contact for better high frequency response and to reduce modulation noise. The backing became shiny PET film, and it was hard to distinguish the oxide from the backing. Premium mastering tapes are coated with a dull, carbon-based backcoating. This means that things have reversed for these tapes: the shiny side is now the oxide recording side.

Recordings are stored "tails" out for two reasons: 1) this leaves the reel in a played-to-end mode with reduced and uniform tension within the pack, and 2) print-through begins to affect tapes in a different flux pattern from that of reels stored with the beginning of the tape at the head. When the master tape is rewound to the beginning, print-through begins all over again; but the process now begins to erase the print signal created in storage. (Sometimes the audibility of a song before it is supposed to start is caused by groove deformation in a vinyl album. Large extrusions of the groove when the initial signal is very loud can affect the "no-signal" groove portion preceding the start of musical content. Good mastering can reduce that pre-signal, and it is rarely worse than print-through.)

 

[sdw54]

What Wilhem said. I stored all my master and source reels tails out back in my engineering days as stated above. But in a Broadcast environment tapes were stored heads out for faster tape loading and use for playback. Guess I'm giving away how long I've been around

 

[Chip Chester]

Making a three-second recording will tell you what you need to know.
And a half-twist before the headstack will let you find out quick.

Chip

 

[cleverdick]

It wasn't too preposterous a presumption; in certain European markets (well into the 1990s), the requirement was for the tape pack to have the oxide layer facing outwards (see here).

https://www.gearslutz.com/board/so-...-f-500-reel-reel-unknown-french-high-end.html

This had the advantage of eliminating pre-echo, without having to store tapes tail-out. Just like Compact Cassette, in fact.

I got to know these machines pretty well, although ours of course were all for oxide-in. Quirky and obscure, yes, but also very good. UK importer was PRECO.

 

[Wilhem]

This had the advantage of eliminating pre-echo, without having to store tapes tail-out. Just like Compact Cassette, in fact

A-winds with the oxide facing outward do not eliminate pre-echo, but they do reduce its effect. Post-echo, however, increases with A-winds in exchange for the reduction of pre-echo. It's all a matter of how the flux lines emanate from the recorded layer.

 

[Chip Chester]

Additional tidbits: Print-thru, which causes pre- or post-echo depending on geometry, is not a biased recording, and can be lessened to a significant degree by shuttling the tape prior to playing. The tape tracking over the guides and lifters is the agent in reducing it.

Storing tails-out addresses that conveniently.

Chip

 

[Wilhem]

The tape tracking over the guides and lifters is the agent in reducing it.

It is not the physical movement over guides and lifters that reduces the print effects, but the realignment of the tape layers that now puts new print effects out of phase with the original, thereby erasing the old while beginning to self-record new print signals. The application of bias penetrates the entire coating during recording so that as many particles are excited as possible so that they magnetically align with the lower frequency analogue signal while passing away from the record head. Print effects lie only on the surface of the magnetic medium because the flux leakage is not great enough to alter any particles other than broken or misshapen, low coercivity particles at the surface.