Radio 3: pre-echo on Liszt loud piano parts

[hooty2]

Writing as it happens:)... Radio 3 building a library/Liszt piano sonata in b minor.
The reviewer commented on a recording from the 70's.. the unfortunate hiss but ..."the annoying pre-echo as the loudest parts are played"

anyone know what this about?

[The Elf]

It's another of those vagaries of tape. When tape was wound on a spool the very loud parts of a recording would bleed onto the tape it was wound against - and often to the layer of tape underneath that too. You can hear the effect of this as the loudest sounds often being faintly heard just before they should arrive.

You can hear this effect on many old recordings. The one I recall most is on Genesis's 'Chamber of 32 Doors', where you can hear the song start twice before it actually comes in!

Tape - I'll dance on its grave...

[ef37a]

I am sure The Doc will give us the precise SP but I understand this is why it was BBC practice to store tapes 'tail out'. This meant they had to be rewound before playback and that reduced print through.

Terrible stuff tape, almost as bad as those flat, black things!

Dave.

[hooty2]

cheers folks... education education education

[Sam Spoons]

I assume the print through would be onto the tape either side of the loud signal not just the wrap underneath? If so you would get both a pre and post echo. Storing tail out would not have solved the issue as the 'sandwich' of plastic film base and oxide means that the oxide layer in a wound tape is separated by a base layer on both sides.

[Wonks]

I assume the print through would be onto the tape either side of the loud signal not just the wrap underneath? If so you would get both a pre and post echo. Storing tail out would not have solved the issue as the 'sandwich' of plastic film base and oxide means that the oxide layer in a wound tape is separated by a base layer on both sides.

There are two types of print-through, one is heat-induced and one magnetic.

If the spool is kept wound in the same position as heat print-through occurs, then the print-through remains. Keeping it stored in a different orientation e.g. fully wound, then the print-through areas no longer correspond, and over time the thermal print-through is supposed to fade.

Won’t do anything for magnetic print-through though.

[forumuser840717]

Apart from other benefits of winding though the tape before playing, storing tail out means that the heaviest print though occurs as post-echo rather than pre-echo so it's masked by the programme.

For geeky interest, there's a bit of info about it in this AES Tech Bulletin

I once came across a Studer A80 which had been modified to run leader tape along with the recording tape, in an attempt to reduce print through by adding a 'spacer layer' to the tape pack. It did work and reduced the print through but wasn't the most practical idea. Not least because the double thickness tape made for odd handling characteristics which used to freak out the transport on many other machines it was put on and the advantages of the lower print through paled into insignificance as someone had to hand re-spool the tape from the floor after the transport on other machines dumped it all when the tension sensors went nuts in fast wind. Assuming they didn't just shred the tape.

[Hugh Robjohns]

Storing tail out would not have solved the issue as the 'sandwich' of plastic film base and oxide means that the oxide layer in a wound tape is separated by a base layer on both sides.

The AES tech bulletin gives chapter and verse, but storing tail out means the tape must be rewound before playing, and the act of rewinding actually helps to diminish the print through by 3dB or so. Weird but true!

[Wonks]

Possibly some static electricity effect, or magnetic separation effect, generated by the much higher tape layer parting speed when running in rewind as opposed to normal forward play speed?

[MOF]

Possibly some static electricity effect, or magnetic separation effect, generated by the much higher tape layer parting speed when running in rewind as opposed to normal forward play speed?

??????? The previous replies are correct Wonks. Apart from ‘static electricity’ nothing else makes sense.
You’re in danger of creating mistakes on the internet.

[Wonks]

I see what you did there.

[MOF]

I see what you did there