Restoring Led Zeppelin

A hit movie about the world’s greatest rock band turns conventional ideas of audio restoration on their head.

“In the early stages of making the film, we met with extraordinary resistance to the concept of playing whole songs,” says Bernard MacMahon. “People were just like, ‘No‑one’s going to be interested in that!’ But if you think that the story of this band is worth you sitting in a theatre for two hours, then I believe you’ve goddamn got to play a whole lot of that music. And if that isn’t a total thrill for the audience, why are you even doing this band in the first place?”

Not only does Becoming Led Zeppelin include full songs, but the team behind the movie also flew in the face of industry convention in their approach to sourcing and preparing this music. Director MacMahon, sound supervisor Nick Bergh, writer, producer and music supervisor Allison McGourty and editor Dan Gitlin had the full cooperation of the band and Atlantic Records. They could therefore have accessed the master tapes, or any of the numerous digital remasters that have been released over the years. Instead, they used the original vinyl records.

“We made a very conscious choice to go with the discs,” says MacMahon, “and the reason is that the tape is often so different from what the public heard. Even if the master tapes survived of all the studio recordings, which a number don’t, they were always made with the mind that they were going to be significantly altered in bringing them to the public on a piece of plastic. The production master was altered from the quarter‑inch that was made in the studio, then that production master was enormously goosed at the cutting stage by a Bob Ludwig.

“What the public heard on their record players is not what you would have heard played back in the studio. So the truest thing is for you to hear the ultimate thing that millions of people bought, in the truest possible way. That’s the philosophy of the film.”

Pressing Matters

The first step was, therefore, to obtain the best possible vinyl copies of everything. This was not as simple as it might appear, given the complex nature of record manufacture in the ’60s and ’70s. Taking Led Zeppelin’s 1969 debut album as an example, “There were many different early pressings of Led Zeppelin I that differ widely in sound quality,” says Nick. “This wide disparity seemed to be largely due to record azimuth errors in the original tape and the various ways mastering engineers were correcting for it, or not correcting for it.”

Director Bernard MacMahon (left) and sound supervisor Nick Bergh (right) review Nick’s transfer of Led Zeppelin I at Endpoint Audio Labs.Photo: Allison McGourty

“Atlantic were using four pressing plants,” continues Bernard, “and on album one, each of those plants had different lacquer cuts made. And the white label test pressings that are very desirable by collectors, that’s another cut as well. And each cutting engineer that’s making the lacquers for those different plants is maybe doing two or three or four lacquers. And each of those might have minor differences, as anything would in the real world. Each of those is different. On the RCA pressing, the channels are the wrong way around! The fans generally seem to think that’s a different mix. It’s not, it just obviously doesn’t sound the same as what they’re familiar with.

“So what was amazing with Led Zeppelin I is that the pressings are radically different in terms of sound and quality. And the best was from George Piros, a classical cutting engineer who came from Mercury [Records]. He didn’t like rock music at all, but he was essentially just getting what was on that tape on the record, and that’s why his is the best.”

So different are the various pressings, in fact, that MacMahon believes this was a factor in the dire press reviews of Zeppelin’s debut album: the white label copies that were sent to journalists were from one of the worst cuts.

The First Cut Is The Loudest

The film concludes with the triumphant release of Zeppelin’s second album, a disc which threw up different but equally confusing choices for the team. “When Led Zeppelin II was completed, it was sent to Bob Ludwig to cut,” reports MacMahon. “Unlike on album one, Ludwig cut all the lacquers for North America. And that record sounds absolutely amazing, and it’s incredibly loud.

“And, as you know, volume on a record is created by the needle moving rapidly and dramatically in the groove — but the apocryphal story is that [Atlantic Records co‑founder and President] Ahmet Ertegun’s daughter had a white label pressing of the record and was playing it on a cheap kids’ turntable and the record was skipping. This was a problem with super‑loud records: they would skip because the needle on a bad hi‑fi would be jumping so much it would bounce out of the grooves.

Eddie Kramer (left) and Jimmy Page mixing Led Zeppelin II. Rather than return to the masters or remasters, the film‑makers chose Bob Ludwig’s original vinyl cut as the definitive representation of the album.Photo: Ron Raffaelli

“So that record was recut. The first 200,000 or whatever copies were this amazing version, and then everything else that was sold subsequently was this much more dialled‑back master with a much less dramatic cut. When you hear the Ludwig cut, the music has this unbelievable excitement to it. It sounds so good that people will now pay upwards of three and a half, four thousand dollars for pristine copies, even though it’s not technically a rare record. Unlike on the first album, all the media would have heard that version. The white labels were all that version, to my knowledge. And that record had a seismic impact in America.”

MacMahon: "When you hear the Ludwig cut, the music has this unbelievable excitement to it. It sounds so good that people will now pay upwards of three and a half, four thousand dollars for pristine copies, even though it’s not technically a rare record."

Transfer Windows

Once the best version of each release had been identified, the next challenge was to track down the best possible copy of that version: ideally, one that has never been played.

“Even a single play can instantly damage the record,” warns Nick. “The louder the cut, the more the stylus is moving in the groove. If you...