Iron Mountain’s Kelly Pribble On Session Archival, Storage, and Securing Your Legacy

It has become crucial for studios and artists to adopt a forward-thinking approach towards preserving their life’s work by archiving their sessions so that they are safe in the event of a natural disaster, technological glitch, or an unknown variable further down the line.  

To understand the importance and intricacies of session archiving, we turned to someone with decades of expertise: Kelly Pribble, Director of Media Preservation Technology at Iron Mountain Media & Archival Services. Kelly is a veteran studio engineer who has spent a lifetime dedicated to music and audio restoration. 

At the young age of 23, he opened and ran the historic Quad Studios in Nashville before moving to London, England to set up and run Kensaltown Studios, overseeing a decade of sessions with artists like Coldplay, Yusuf Islam aka Cat Stevens, KT Tunstall, James Morrison, Jason Mraz, and more. 

After returning to the US, Kelly joined media archival giant Iron Mountain, a company that has been offering top-of-the-line storage services since it was founded, against the backdrop of the Cold War, in 1951. 

If you’ve been curious about proper session archival methods, you won’t find a better starting point than this blog. We sat down with Kelly recently and he generously shared learnings and best practices for session archiving from his long and illustrious career. 

Read on to learn about the importance of archiving your work, the biggest mistakes people make, how to manage your hard drives, Kelly’s favorite gear for archiving, and more.    

Tell us about the work you do at Iron Mountain.

One of the many things Iron Mountain does as a company is store assets. One of the things that is connected to me is, we provide climate-controlled high-security vaults around the world for media assets. We work with record labels, film companies, large and small corporations with archives… any kind of company that has media assets or content related to the company and its history.

In 2010, Iron Mountain was working on a project in Rio de Janeiro, Brazil, where a lot of tapes had become moldy. They asked if I would go to Brazil and see if I could figure out how to fix this. When I went down there, I realized there were over 7000 tapes that had become wet – it was not a good situation. I built a team for that project, and that's where remediation really started for me – working on tapes that had mold issues or contamination from storage and things like that.

Then we started seeing that analog tapes from the ‘70s into the ‘90s were degrading rapidly for some reason. No one had seen this in the US, but I started seeing a lot of it in Brazil, and one of the reasons was part of the recipe of the tape. There’s a kind of lubricant in the recipe so that when the tape goes across a stationary head, it doesn't squeal or stop. That lubricant was coming to the surface and causing all kinds of problems – tapes were also bound or stuck together from layer to layer on the edges and as we unwound them, it would literally destroy the tape because it was bound together. I named this issue “Adhesion Syndrome”.

I started reaching out to every expert in the world, showing them pictures, and nobody had ever seen these issues before. So, I just started experimenting and came up with a process by which we could actually get the tapes unbound. We thought at the time it was isolated to South America but then there was an incident in New Jersey, so I was going back and forth, taking care of these tapes that have these issues. In 2013, Iron Mountain asked me if I would consider staying in New Jersey after I finished the Brazil project to build and help get their audio and video studios started on the East Coast. 

Now, in New Jersey, we have four audio suites and a large video studio, as well as a remediation lab. We have five studio locations in the US, and globally in London and in Paris.

So, we can now offer the same services globally. In 2016, we applied for a patent for all my techniques for working with media that is in a state of degradation and I actually received my first patent in 2022 for Media Recovery Technology.

What are the main benefits of archiving your sessions?

The short answer is: always archive as much as you can because you don't know when that information is going to become non-retrievable. 

I was making records on analog tape in the ‘80s and ’90s, and then with the digital revolution, we went to digital tape, workstations, and hard drives. No one then was thinking, “Hey, will this analog 2-inch tape play in 25 years? Will we be able to boot this hard drive with Pro Tools early versions 1, 2, or 4?” 

There was no concern about that because we thought everything was going to last forever – and I'm just as guilty of that, being a part of the industry. We would back up sessions on digital tapes for long-term storage and we thought that was going to last forever. Now, we know that there's a time limit on everything that we do: whether it's a hard drive, whether it's a tape, no matter the format.  

What we’re also seeing is that when people did archive, say in the early 2000s on AIT tapes or some digital format tapes, we can't read it with today's computers! So, we have to have legacy equipment and software that dates back 25 years to be able to actually read those tapes and then retrieve that data as a new archive.  

There was an original archive, but now those archives are so old and our computers are so far advanced, that we can't even plug those hard drives into the current computers. So, I have to have legacy rigs of a 25-year-old Mac tower today to be able to recover archives from the early 2000s. We are archiving early archives that are not physically that old, but technology-wise, ancient, and sometimes non-retrievable!

So, the biggest thing now, whether you're doing something on your DAW in your bedroom or in a studio, is to think about this: “Are we going to be able to play those files or that tape in 20 or 25 years?” And if you don't start thinking about archiving what you're working on today, that stuff may not be retrievable in 20 years. 

I give a lot of educational talks and presentations to students and educators. All these schools have amazing studios, but nobody talks about this because, in today's society, we think everything is going to last forever. Working with archival collections, I know it doesn’t. We're having to go back and recover master sessions with today's modern archiving capabilities, and it takes a lot of equipment and is expensive to do.

So, archive as much as possible, and regularly migrate to new formats?

Exactly! Also, have multiple archives. This goes back to the “Law of Averages,” which is: two might fail, three probably won’t. That’s triple redundancy and I’ll give you an example to understand why we do it in threes. Every commercial airplane has three systems on it so if System 1 breaks for some reason, you've got two other systems that take over in the middle of the flight. So, we try to explain that in a simple way

If you have a hard drive in one location, we suggest you have two more hard drives in two different locations, because if we have a situation like the LA fires or a natural disaster and the first hard drive gets deleted or destroyed, you've got two other backups somewhere else. 

I have a lock box in a bank that costs me $100 a year – it's fireproof and it's in a bank. You go, “Okay, I'm going to put my hard drive in there, and every few years I'm going to pull one out, convert it to a newer drive, and put it back in.” It ensures redundancy of my archives because if I've only had one copy at my house with my DAW and I have a natural disaster, all of that is lost. 

So, you want to keep storing and updating, but I understand that it's sometimes costly and it's also physically difficult to go to three different places. There are certain studios that, at the end of the day, when you're recording a session at the studio, will back it up to two other hard drives right then, so just in case that original hard drive fails, you've got two more backups.

There’s no magic bullet on storage right now – we’re even seeing some new SSD hard drives fail – so you've got to think about this: “What if something happens and I lose what I have in my home or in my studio, do I have backup?” Triple redundancy needs to be enacted because the law of averages says if you've got three copies, there’s a pretty good chance you're going to be able to recover your data before something bad happens

When it comes to triple redundancy, what is your take on cloud storage being one of the ways people can back up their sessions? ​

Great question! I think cloud storage could be one of the redundancies for sure. This provides for separate geographic storage/placement in a way that is cheap to store and easily accessible. 

Redundancy could be separate cloud storage accounts as well. The main goal is to not have all your data in one location, if possible. When there is a natural disaster like the LA fires, cloud storage would definitely have an advantage over physical storage in some cases. Just make sure your bill is paid! [Laughs]

What are the biggest threats to media assets in storage?

If you're in a climate that has high humidity, you have to take extra precautions because it's the elements that you're fighting against. I've dealt with analog tapes that were stored close to the ocean for decades for a particular artist. When I got the tape, it was covered with salt residue that was so thick, it ate into the tape and damaged it quite extensively. They were multitrack masters and I was able to recover them, but it was one of those things that nobody had thought about. 

For the longest time, record labels thought a 2-track mix copy, a DAT, or a CD was all they were ever going to need. Fast forward 30 years and we've got immersive sound, and you can’t take all the tracks from a CD or a 2-track master and bring them back. There’s some AI out there now that could maybe go into a 2-track and actually distinguish the different instruments and be able to separate them out, but that’s the future and if the humidity is really bad, you're damaging the internal parts of your hard drive, so you need to take measures to keep your hard drives in a climate-controlled space. It doesn't have to be perfect, but try to keep it out of the extremes, because that's going to be detrimental to being able to open those drives in the future. 

Any other dangers that we're not aware of, other than humidity and heat?

The unknown or unexpected. That's the thing about natural disasters and that's where we go back to the redundancies of having your work backed up in multiple ways or possibly even geographical separation. Not everybody can do that, I get it, but if you get a little creative… like I said, get a lockbox or put a drive at your parents’ house, or somewhere safe that you know you can go back to if you can.

In terms of the actual hard drives, everybody thought the SSDs were going to be the saving grace of dead hard drives, but they’re dying as well. So, there's nothing foolproof and that's why we go, ‘redundancy, redundancy’. 

There's no guarantee. Hard drive manufacturers say, ‘We're going to guarantee our drive for 10 years’, but they're not going to guarantee the content, they're only going to guarantee the drive. 

So they could fix your drive but you’ve probably lost all your content?

Exactly! “Here’s a brand-new drive, thank you.” There is no insurance on your content at all! Even the tape manufacturers back in the day had a disclaimer on the back of the tape that the guarantee only covers the replacement of the tape. Nothing else.

Every couple of years, migrate to a higher drive. Don’t wait 10 years because what we're going to be working on in 10 years is not going to be compatible with what we're dealing with today. 

The evolution of re-archiving your archive is very important. We can’t predict future technology whatsoever, so part of being a musician or artist is making sure your stuff is recoverable in the future.

Not only does hardware become obsolete, but so does software, right? When archiving your sessions, what do you do about the fact that the software and plug-ins used in the session probably won't be compatible with future operating systems?   

One of the things you can do is what we call consolidating a session. In a Pro Tools session, for example, there are little segments that you see scattered all around the song – they only feature once, or only in a couple of parts of the song. What we like to suggest is to render each of those segments as a full track from the start to the end of the song so they’re not sectioned. So, at some point, if I can't open the session that puts all those things in place, I have files from zero to the end of the song that indicate exactly where those placements are and I can open them up in a new DAW. By doing a consolidation of every track, they’re now just WAV files and you can bring them up into any software out there. 

We call that consolidation or “bar 1/beat 1”, which is what they call it in Europe. Consolidate the file from the beginning of the song to the end of the song, and if there's a plug-in that makes that sound happen, that's going to be in that file or create a new file / track of that effect or plug-in.

That’s helpful for the future because we may not be able to bring those plug-ins back. We see that every day: somebody goes, “I want you to recall a session on Pro Tools”, but we don't have the exact plug-ins that the session used, so we're never going to be able to recover exactly what those files are or what that record sounded like because those plug-ins are now obsolete. But there is a way to future-proof that by doing the consolidations.

What are some of the other mistakes people make when it comes to archiving their source material?

The biggest one I find is that the metadata is missing! And what I mean by metadata is the information: What version of the software were you working on? What happened in your sessions? Are there plug-ins? Any information that you can put on that drive or on the tape or whatever it is – that information is vitally important for the future to be able to recover your data. If it's not there, we don't know what is recoverable or how to even approach it because we don't know what's on that drive or tape.

You’ve got to think, ‘If I'm making a record in my home today in my DAW and it’s going to be on a hard drive, what are all the key things that went into making that music that rest on that hard drive?’ Those things need to be written down somewhere. And if this is a major record, in 20 years we'll be at higher resolutions and when we want to go back to the original files and remaster it again, we need to know what version of the software it was made on. You need the information of what you did today on those assets to stay with those assets.

One of the other things that we always do in the studio systems is, we try to have a dedicated computer for our DAWs because we try to keep them running as smoothly as possible and make sure nothing is running in the background and bogging them down. Have a dedicated computer for your workstation, or it could become corruptible because you're working on ten different things on the same computer. Try to stay away from introducing anything that could corrupt the current status of what you're recording. 

Let's talk about some of the key gear that you use in your process.

I use Prism Sound converters; I bought them from Vintage King many years ago, actually. One of the things that used to bother me with some of the converters or the I/Os that I would use is, when I was archiving a tape, I was hearing the input to the DAW and hearing exactly what's on the tape. When I played it back, that's where I kept hearing a difference and that was basically just different converters, or there could be some kind of an EQ on the output of the converters. It bothered me that I could hear the difference between the input and the output until I found the Prisms. 

The ones I use are the ADA-8XRs (which are about to be discontinued), but until I found those converters, everything sounded different coming back from my DAW. Since I've been using the Prisms, I can't hear the difference. I hear exactly what I'm putting in coming back out, so that was one of the reasons I stuck with those. 

I stand by those because, when archiving, I want to be able to present, digitally, exactly what's on the tape. There may be other ones out there now that are as good, but I'm not aware of them. I've been using these for probably ten years now and they are the best for me so far. I started getting to know the amazing guys from Prism well and they've got a new unit that we're going to demo pretty soon; it’s so much more compact. 

As far as tape machines go, we're using legacy tape machines. We have four studios in the US and two in Western Europe and we all use Ampex ATR machines. With something like an Ampex ATR 104 and different head stack combinations, I can archive mono, 2-track, 3-track, 4-track, and either half-inch or quarter-inch, so that one machine can do so many different formats. 

And then all of our multitrack tapes go on Studer A827s which was the Rolls Royce of 24-track machines when they were made, but they haven't been made for 40 years now, or even maybe longer, which creates a problem in itself.

That’s my go-to: the early Ampex tape machines and the Studers going into my Prisms. It’s a clean, short run and I try to get the least possible resistance going from tape to my Prisms. 

On the output, I use Dynaudio speakers. I've been using them for years because they’re very transparent and that's pretty much mostly my rig for archiving. It’s very simple and very compact. 

Is there any other gear you recommend that is key to the session archival process? 

Depending on what formats you are archiving, many components could be needed. Here’s a list of items needed for archiving multiple formats:

• Splicing blocks of various sizes
• Leader and splicing tape of various sizes
• A solid computer platform, such as a Mac
• Professional DAW
• An array of analog playback tape head configurations from ¼-inch to 2-inch, mono to 24-track, to convert a machine to different formats
• DAT, analog cassette, and digital multitrack machines
• Hard drives and appropriate backup solutions
• Asset metadata software
• Outboard noise reduction processors (Dolby A, SR, and dbx encoder/decoders)
• Timecode synchronization
• High-quality master clock

I read an interesting quote from an article on the Iron Mountain archival process: “The maintenance of a master tape is necessary even after its content has been transferred to a digital source.” Tell us a little bit more about why that is. 

That's a great question! A lot of people don't understand what that statement is about. I'm going to give you another example: remember standard definition TV? Then we went to 4K, and if you look at a normal SD picture on a 4K TV, it was square, had black sides and it wasn't big enough because now the 4K was so much of a higher resolution that the lower SD file couldn't complete the whole picture.

So right now, if we digitize a tape at 192 kHz, as resolution rises at some point in the near future, we're going to want to double that to 384 kHz but those 192 kHz files can never up-res to a higher resolution – they’re capped at 192 kHz. So, we're going to want to keep that original tape in as good a condition as possible, so that as resolution rises, we're going to re-digitize at a higher resolution, and for that, we want to go back to the original source.

You always want to keep the original source as long as you can, because there are overtones and things going on, on that analog tape, such as a bias tone on an analog tape, at 150 kHz. Recording at 192 kHz cuts things off at half, which is 96 kHz; so 192 kHz is not really giving you 192 kHz, you're getting half of that.

As resolutions rise, we're going to want to go back to the original masters and capture all the essence of that master. So, there needs to be maintenance done on the master, in terms of climate control, where it is stored, and how it's stored, because we want to keep that original master as long as possible.

Now this brings up a pretty new topic that I would like to talk to you about because I'm starting to be convinced it might be worth it. I'm really starting to look at the possibility, while I'm doing 192 kHz files, of also doing an analog-to-analog copy because we're seeing such degradation with some of these tapes that in five to ten years when the resolution gets higher, this original tape that’s degrading now, may not be playable. And then all we're going to have are those 192 kHz files that we're not going to be able to up-res. But we could if I have a really good analog-to-analog copy that I hit really hard, level-wise; and the analog tapes that you can buy today, you can hit really hard.

There used to be this theory, back in the ‘70s and ‘80s that if you copy an analog tape from one tape to the next, it's considered second generation because you're hearing the noise floor of the first tape but you're also adding the noise floor of the second tape, which is then second generation – it’s not as good as the first. But now, with the ability to hit a tape at a level of +9, the noise floor on that second tape is so low it's not impacting the sound.

So, I'm looking at suggesting, on certain tapes of monumental artists, or if there's a one-of-a-kind master, of maybe doing an analog-to-analog copy today to preserve it, because if we can't play that original in 10 years, we’ll at least have a new tape that’s probably going to last for another 10 or 20 years like the original did before it starts degrading. I'm really starting to entertain that idea and it keeps me up at night, [laughs] really, because I'm going, “How many tapes should I have suggested this for before?” 

We see the benefits of session archival in several Iron Mountain projects. Let’s talk about the Appalshop project that was part of the Living Legacy Initiative and then about the Bob Dylan project.

The Living Legacy Initiative is Iron Mountain’s corporate philanthropy effort, which looks for culturally significant projects and provides funds to be able to recover or help a situation. 

The Appalshop Museum started in the ‘60s and was created to document the culture of the Appalachian people through film, video, and audio. It is a part of American history – bluegrass music, folklore, crafts, and so much more have come out of the Appalachian Mountains and the culture there. They’re very hardworking people, so Appalshop started as a government project to train young adults in the Appalachian area in how to shoot and develop film and record audio and video because they felt like they weren't getting represented properly in any way by the media. It was a community center that was based upon archiving the culture of the Appalachian people. 

Two summers ago, they had what is called ‘the thousand-year flood’; it rained for days and a river close by flooded the Appalshop Archive. It happened so quickly that they were unable to move anything, so the entire library of the documentation of Appalachian culture – audio, video, film, papers, and photographs – was submerged in floodwaters. 

They approached us and one of the first things we wanted to do was get everything out of that climate. It was the middle of July when this happened, and it was really hot, humid, and mold set in very quickly. So Appalshop dried it, bagged it and, through Living Legacy, we were able to bring it to our underground facility in Boyers, Pennsylvania, and put it in cold storage to stop the degradation.

The tapes came to me, I reevaluated some technology that I have a patent on, created a new machine, and we were able to remove the mud from the tapes without hurting them and actually recover the footage as a proof of concept. We digitized and sent it back, and they were floored because they didn't think they'd ever be able to see that footage anymore. 

This horrible catastrophe threatened the ability to archive Appalachian culture, along with the ability to observe, enjoy, and celebrate it in years to come. If Living Legacy hadn't have been able to step in, I wouldn't be able to prove that I can actually recover this media.

Appalshop is still trying to raise money for that project; there are 9000 pieces of media, whether it's video or audio, that have to be remediated, cleaned, and digitized. I am dedicated to that project, come hell or high water. It’s a very personal project for me and it’s one of those projects that is going to define my legacy; I'm extremely proud of being able to help these people recover what they've lost. I grew up not very far from there, I knew a lot of those people, the culture, the music… The Appalachian culture is fascinating to me and it's a part of Americana that is very important.  

Look at the LA fires, which is another natural disaster – people went to work or they got evacuated and they lost everything; there's nothing to recover. That's why we need triple redundancies; that could have helped a lot of people if more people would have known that.

What I'm also trying is to figure out how to create an ‘Archive Yourself’ situation, maybe an app, where you scan, for example, photos of your loved ones who are no longer here. It’s your personal legacy. In archiving, the big question now is: how many of us have archived our personal lives? Because the LA fires really highlighted how you can lose all of your personal history. That’s a fact, and it's probably one of the biggest eye-openers I've had in a long time. 

So, I'm personally working on that and I'm hoping we're going to be able to come up with something in the future.

This subject has bothered me for over a decade, to be honest with you, and I haven't found the avenue to get it out there. We’re talking about archiving music and historical things, but our personal archive is just as important. Life is short, life is precious, and archiving your life is very important.

That actually sounds like it could come from a Bob Dylan song, so maybe that's our cue to talk about him. 

[Laughs] All right, let's talk about Bob Dylan! This is one of the coolest projects I've worked on. So, a few years before The Bob Dylan Center opened in Tulsa, Oklahoma, they started archiving tapes that would be used in their exhibitions They came across two albums that they sent to another archivist in New Jersey who I know pretty well and when he got them, he found that they were bound with adhesion syndrome – the same thing I had seen in Brazil.

I had done a presentation at the Library of Congress a year before, where I displayed my machines and processes to this crowd of archivists from around the world. Fast forward a year later, and this archivist calls me and says, “I have some tapes that are bound like those videos you showed at the Library of Congress”. I asked, “Well, how many do you have?” He said, “I have 63.” And I said, “Who’s the artist?” He answered: Bob Dylan. That’s how it happened!

There were two records – ‘Knocked Out Loaded’, and ‘Empire Burlesque’ – both of which were recorded between 1984 and 1986, and all the 2-inch multitrack master tapes were bound. I was able to get everything completely unbound and we were able to digitize them and return them to the Bob Dylan Center. 

These were the original multitrack masters and the greatest thing for me as an archivist, musician, and recording engineer was that I got to be a fly on the wall for two Bob Dylan records. I heard the banter between Bob, the engineers, and the other studio musicians; it seemed like Bob would start playing a guitar riff, the band would join in, and then he would start humming some melody or lyrics. You could hear them creating the songs in the studio, and several of them ended up being on the record.

Having been in so many sessions around the world with big artists, this was mind-blowing for me because when I was transferring those tapes, I got to hear how Bob Dylan made records in that time period.  

The team at the Bob Dylan Center is amazing! Truly dedicated to the preservation of Bob Dylan’s life and career. It’s a wonderful place to visit and a highlight of my career to work with them.

The one thing I always want to say when I'm talking about these masters is there was no fault with the storage. It was just natural degradation that we're seeing more and more often, particularly now from tapes in the ‘70s and ‘80s, whether it's the lubricant that's coming off or it's the adhesion where the tape is bound.

So, we know it's an age thing and we know it's a degradation that's happening over time and it's getting worse and that's why we're trying to educate people now. I'm doing educational panels with students and with record labels to say, ‘Hey, if it happens to Bob Dylan from 1985, that's a problem!’ 

You and I could go to a museum today, and see a book or a painting that's 500 or 600 years old that’s in good condition. Guess what? That’s metadata! That’s old entertainment. A painting is metadata, a Bible from the 12th century is metadata, and we're able to see these kinds of things that are hundreds and hundreds of years old but then I’ve got tapes from the mid-80s falling apart. That troubles me and so my quest in the last seven or eight years is about educating people.

A pretty common response when I talk to estates or artists about this is, “We don't have a budget for that.” Well, at some point you're going to have to have budgets to do this because otherwise you're going to lose everything. It's possible you're going to lose it before you know it, and there are a limited number of professionals who know how to deal with it today.

I've got a machine being built currently that's going to come out in the next six months hopefully, that automates my processes. So, the future for me, as part of Iron Mountain, because we have millions of assets around the world, is how quickly we can archive these. We need people to realize that future generations have to be able to appreciate this work, whether it's audio, video, or film. If we don't get on this today, we know we're going to lose it. It’s just a fact and a race against time. My goal is to get in front of it.

If you’re interested in purchasing gear for session archival, contact a Vintage King Audio Consultant via email or by phone at 866.644.0160.