1/4" Tape Heads and History

[Siegfried Meier]

Hey guys!

I need some advice from the oldschool tape dudes here...I'm having an issue transferring 4 specific reels for a client, and they're all dated around 1967.  Let me explain.

So I have a very nice Technics RS1500 with the 4 track playback heads that seems to be able to reproduce most 1/4 track stereo tapes just fine - Side A and Side B when I turn the reel over.  As I understand it, most modern 4 track tape heads are staggered, so they'd look like this:

-------------------
Left, "Side" 1-->
<--2 "ediS" ,thgiR
Right, "Side" 1-->
<--2 "ediS" ,tfeL
------------------

But, was there a time in the early days of stereo and 4 track heads that they were next to each other instead?  That would explain why I can play one side of these tapes perfectly, but when I turn the reels around all I get is reverse music...I'm basically stuck with only playing Side A of all these tapes with no access to Side B...

Otherwise, I can't understand why I can't play these tapes...anyone have any advice?

Thanks!!
Sig

 

[RuudNL]

If you use a 'real' 4-track machine, you can listen to all individual tracks.
For example a Teac 3340/3440.
The track identification you gave is correct.

 

[ruffrecords]

Are you sure they are quarter track stereo? There were quite a few tapes around in the 60s that were half track stereo. This would explain why you only hear revers music when you turn it over.

Cheers

Ian

 

[gyraf]

..around here, half-track-stereo was the standard for pre-recorded..

/Jakob E.

 

[abbey road d enfer]

Wasn't there any clue as to what format they had been recorded to? I vouch for Ian and Jakob's conclusions.

 

[RuudNL]

If you play a 2 x 1/2 track tape on a 2 x 1/4 track machine, the level of the right channel may be lower, because only part of the track is played with the width of the 1/4 track playback head. (track width: 2 mm, separation between tracks 2.25 mm.)
Only if the 2 x 1/2 track tape was recorded on a machine with 'butterfly heads' (wider tracks), there is a chance that you may get the correct level for the right channel. (track witdth 2.75 mm, separation between tracks 0.75 mm.)

 

[Tubetec]

Are you certain your tapes were actually recorded in quarter track format?
What you describe seems to suggest either a half track stereo or full track mono machine was used .
In any case if its domestically recorded the chances of actual stereo recordings being on the tape is very small , especially if its spoken word. One other possibility could be quadraphonic four track, where four tracks are stripped across the tape in the one direction , thats probably the least likely situation . The butterfly heads issue as mentioned by Ruud is probably unlikely also as that was really only seen in pro recording/broadcast scenarios.

Does the labeling on the tape relate specifically to the recordings you've found on there ? you could have a tape originally recorded in quarter track , only to be later recorded over and not labeled properly . I guess often these tapes turn up years later long after the person who recorded them are gone so the details are lost in time .

Heres a simple guide to 1/4 inch tape formats.

https://www.petervis.com/Cassette_Tape_Recorders/sony-tc-330/reel-to-reel-track-formats.html

 

[Siegfried Meier]

Of course, the one tape isn't labelled at all so I can't know exactly what configuration it might have been recorded in...the other one does only say 1/4 track stereo, but I'm sure it's possible someone wrote the incorrect information there!  This was a consumer type tape, so who knows who wrote that!

 

[Siegfried Meier]

Are you sure they are quarter track stereo? There were quite a few tapes around in the 60s that were half track stereo. This would explain why you only hear revers music when you turn it over.

Cheers

Ian

The docs for that specific tape do say Side A and Side B, and says 1/4 track stereo...but the other side is just all in reverse...of course, maybe i'm trusting someone that wrote on a tape from the 60s too much here!

 

[cyrano]

You can make the tracks visible with a piece of magnetic sensitive plastic. There was once a device for sale for doing exactly that, from a company called "Arnold" or something like it.

AFAIK that's the only way to really tell if you've got a two-track or four-track tape.

I've only seen pics of the Arnold thing on ebay, but I've used magnetically sensitive plastic myself to decide what tape I get.

 

[Winston OBoogie]

Just transfer side B backwards and then flip it in your DAW?