Radio 3: pre-echo on Liszt loud piano parts

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Re: Radio 3: pre-echo on Liszt loud piano parts

Post by Tim Gillett »

FrankF wrote: Thu Aug 05, 2021 12:28 pm Very interesting that there's no mention of Ampex tapes in all of that.

That said, my abiding memory of Ampex is peppered with swear words and flecked with the spittle of despair, as I transferred all my recordings from a Fostex analogue to an AKAI digital, and shovelled up the fragments from the carpet...

It's true some Ampex tapes exhibited binder hydrolysis, but so did some 3M Scotch and Sony tapes. Possibly some BASF tapes and others. Countless recordings were affected. The standard temporary fix of controlled baking before winding or playing tapes has been in use for decades.

Unfortunately because it involves raising the temperature of the tape to 50 deg C or more for maybe 24 to 48 hours or more, tape baking will tend to make the print through problem, the subject of this thread, even worse. But it's been found to be a sensible tradeoff compared to possibly ruining the recording by attempting a play without first baking out the moisture.

I once tried to manually remove pre and post echo in a solo voice recording running to some six hours. It involved sampling some room ambience and cutting and pasting the ambience into all silences between the speech. Sometimes the speech wasnt enough to mask all remaining echoes but overall it made for a more listenable product. Maybe someone has developed a software tool which can sense silences prone to print though echoes and automatically substitute in clean room ambience.

https://richardhess.com/notes/formats/m ... ing-tapes/
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Re: Radio 3: pre-echo on Liszt loud piano parts

Post by MOF »

I remember some years ago there was a gentleman from America who wrote for SOS for a while, he had links to a company that used a vacuum process instead of baking. I think a chemical was added that prevented hydrolysis happening again.
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Re: Radio 3: pre-echo on Liszt loud piano parts

Post by Tim Gillett »

Yes I believe vacuuming is also effective but apparently the treatment time frame is much longer.

I guess the problem with any sort of sealant to lock out moisture re entry would be that it would have a thickness resulting in a minute separation of the oxide from intimate contact with the head face, or a "spacing loss", which is notorious for loss of highs in playback, similar to a dirty head.

A similar technique involving "wet play" of tapes which squeal on playback, resulting in nasty FM modulation of the audio, reduces the squeal but also results in a significant loss of highs in the transfer, again due to spacing loss.

So often real world solutions involve trade offs.
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Re: Radio 3: pre-echo on Liszt loud piano parts

Post by FrankF »

This thread is starting to sound like the great British Radio Bakeoff. :oops:

As soon as CDs came along, I gave up on tape as a lost cause.
However, putting on my Advocatus Diaboli hat, I also have some CDs with mysterious digital distortion on them: for example, the 5 vol. complete Erik Satie piano works on EMI, played by Aldo Ciccolini.
He recorded the complete piano works twice: once in the 60s (ADD), and then again in the 80s (DDD).
Now, guess which recordings have the digital distortion?
Yep! It's the later versions.
I can thoroughly recommend the 60s box set, however, if you can find it.
As Sylvian sang, it's full of the most poignant "désespoir agréable".

Getting back to Radio 3, it would be interesting to know which recordings of these works they recommend in Building a Library.
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Re: Radio 3: pre-echo on Liszt loud piano parts

Post by MOF »

I guess the problem with any sort of sealant to lock out moisture re entry would be that it would have a thickness resulting in a minute separation of the oxide from intimate contact with the head face

I don’t think it was a sealant, it was there to change the chemical nature of the binder so that it didn’t hydrolise.
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Re: Radio 3: pre-echo on Liszt loud piano parts

Post by MOF »

He recorded the complete piano works twice: once in the 60s (ADD), and then again in the 80s (DDD).
Now, guess which recordings have the digital distortion?

For a 60s recording it would have to be AAD.
Have you ripped the 80s recording into your computer to see the waveforms? It just might be the CD player distorting if the mastering took the peaks to extremely close to 0dbFS.
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Re: Radio 3: pre-echo on Liszt loud piano parts

Post by Hugh Robjohns »

FrankF wrote: Thu Aug 05, 2021 1:52 pm I also have some CDs with mysterious digital distortion on them: for example, the 5 vol. complete Erik Satie piano works on EMI, played by Aldo Ciccolini.
He recorded the complete piano works twice: once in the 60s (ADD), and then again in the 80s (DDD).

That doesn't sound right. The first letter describes the original recording format, the second is the mixing format, and the last is the mastering format.

A recording made in the 60s must have been AAD, not ADD...

Now, guess which recordings have the digital distortion?

It could be either, of course, and for lots of reasons -- all inexcusable, naturally -- but I'm guessing you're not a fan of the later recordings.
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Re: Radio 3: pre-echo on Liszt loud piano parts

Post by Tim Gillett »

MOF wrote: Thu Aug 05, 2021 2:43 pm
I guess the problem with any sort of sealant to lock out moisture re entry would be that it would have a thickness resulting in a minute separation of the oxide from intimate contact with the head face

I don’t think it was a sealant, it was there to change the chemical nature of the binder so that it didn’t hydrolise.

I'd be interesting to know more then.
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Re: Radio 3: pre-echo on Liszt loud piano parts

Post by MOF »

I'd be interesting to know more then.

It was some years ago Tim, I’d have to trawl through all my paper copies. Maybe someone at SOS remembers who the author was.
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Re: Radio 3: pre-echo on Liszt loud piano parts

Post by forumuser840717 »

Possibly Roger Nichols's archiving work through Digital Atomics? They used to refer to using a vacuum dessication process.

It was done at a couple of places I worked too (in the UK) and I vaguely remember mentioning it on the forums a very long time ago but I've never written for SOS whereas Roger did.
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Re: Radio 3: pre-echo on Liszt loud piano parts

Post by FrankF »

Hugh Robjohns wrote: Thu Aug 05, 2021 3:29 pm That doesn't sound right. The first letter describes the original recording format, the second is the mixing format, and the last is the mastering format.

A recording made in the 60s must have been AAD, not ADD...


It says the recordings were made between 1966-1971, then "digital transfers and mixing - 1991".
Does that make it AAD or ADD?
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Re: Radio 3: pre-echo on Liszt loud piano parts

Post by forumuser840717 »

MOF wrote: Thu Aug 05, 2021 2:52 pm
He recorded the complete piano works twice: once in the 60s (ADD), and then again in the 80s (DDD).
Now, guess which recordings have the digital distortion?

For a 60s recording it would have to be AAD.
Have you ripped the 80s recording into your computer to see the waveforms? It just might be the CD player distorting if the mastering took the peaks to extremely close to 0dbFS.

It could be ADD if the original analogue recording were remixed/re-edited digitally. In classical world, the majority of sessions were mixed to stereo live, on the sessions, so the second letter commonly refers to the post production stage (normally just editing and perhaps a little mastering) rather than mixing in the more familiar pop sense of tracking-mixing-mastering.

I've done work re-editing/re-mastering old recordings from analogue tapes where the end result was identified as ADD even though the original release was AAA and happened before I was born!
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Re: Radio 3: pre-echo on Liszt loud piano parts

Post by MOF »

I've done work re-editing/re-mastering old recordings from analogue tapes where the end result was identified as ADD even though the original release was AAA and happened before I was born!

Well according to this article you're breaking the trades description act. :lol: Apart from a short gap 1991-5 it's as Hugh mentioned above - recording, mixing and mastered format.
https://en.wikipedia.org/wiki/SPARS_code
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Re: Radio 3: pre-echo on Liszt loud piano parts

Post by MOF »

Thanks forumuser840717, it was Roger Nichols July 2006 article
As everyone knows by now, analogue tape suffers from 'sticky shed syndrome'. The tape companies suggested baking the tapes to enable playback temporarily. In 1992 I started using a vacuum process to recover these tapes; I enlisted one of the original scientists who developed Mylar and the oxide binders for DuPont to help develop it. It works perfectly and turns out to be permanent. Tapes processed in 1992 still play back perfectly today, without the increase in distortion as a result of baking.

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Re: Radio 3: pre-echo on Liszt loud piano parts

Post by Hugh Robjohns »

FrankF wrote: Thu Aug 05, 2021 5:26 pmIt says the recordings were made between 1966-1971, then "digital transfers and mixing - 1991".Does that make it AAD or ADD?

Ah... okay then, if remixing was involved in 1991 that stage could have ended up on a digital format to make it ADD. Fair enough.
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