Best option for converting irreplaceable cassettes to digital format?

December 2, 2015 7:49 AM

I have about 80 cassette recordings of interviews dating from the early 1990s that I need to convert to some kind of digital format. What are my options if my priority is the preservation of the tapes? Is there a "gentle" tape deck on the market?

I have no idea what condition the tapes are in or what the sound quality of the recordings are like. (The tapes have been in a cardboard box in a file cabinet until a few months ago and are now on a shelf in my office.) They are mostly high-quality TDK cassettes and look like new, but I don't want to just stick them in whatever Yorx walkman I can find for fear of chewing them up.

Expense is not a huge issue. I'm prepared to ship these cassettes to a vendor that does this kind of archival work, but I'm a bit nervous about sending them through the mail for fear of them getting damaged or lost. If it existed, I'd probably prefer to purchase some kind of high-quality tape deck that could do this conversion automatically myself. (I don't really want to connect a regular tape deck to my iMac and manually make all of these recordings in Audacity myself - too time-consuming.) Does this exist?

Whether I convert myself or send them off, I don't have and will need to get some kind of tape player to listen to at least some of these tapes to verify the accuracy of transcripts whether or not I do the conversion myself. Is there a brand or model on the market today known for high-quality rollers (and whatever else all the contact points are)?

posted by ndg to Technology (9 answers total)

Try ebay for old high end casette machines. If you go the DIY route. I looked up the cost of one and they fall between $24-$70 US. Casette used to be the thing, so there was solid, high end, gentle equipment. If you can play these casettes with good fidelity, sound capture has really advanced. You should be able to record in a quiet place with a microphone, just as if they were talking in the room.

Look at Technics Stereo Casette Deck RS B18, as an example. I saw three of these on Ebay, right off the bat. (I am not in this business.)
posted by Oyéah at 9:30 AM on December 2, 2015

Don’t use a microphone - plug the line out from a decent tape deck straight into the line in of any half-reasonable sound card and record straight to wav.

(Half reasonable in this context means: try whatever is built into your PC / Mac and see what the noise levels are like. Acceptable? Just use that. No Acceptable? Go out and buy a USB sound device and plug the cable into that instead.)
posted by pharm at 9:41 AM on December 2, 2015

I'd think that whatever machine might do the conversion automatically for you will take just as much time to do it as you will take to do it with an iMac and Audacity. Unless you want to go back and edit things after the fact, it would be pretty much start it, let it run, stop it when the tope is done.

That said, I don't know if machines that are one-box solutions exist.
posted by BillMcMurdo at 9:58 AM on December 2, 2015

There's a pretty major factor in transferring old cassettes that most folks don't really think about: Every cassette you've ever recorded still bears the sonic marks of the machine it was recorded on. The condition and quality of the original deck will imprint on the product you hold in your hands today. The most obvious example of this, that most folks have some experience with, is when you record on a deck with low batteries; the resultant recording sounds that much faster on a deck at normal speed. You might also hear this phenomenon on a deck with gummy capstans or rollers; the pitch of the recording can warble or drift based on that impairment.

But cassette heads themselves are also inconsistently aligned. The technical term for this alignment is called azimuth: Azimuth is the angle of the magnetic gap in the tape head relative to the tape. Pretty much every cassette deck, from unit to unit, will have a microscopically different azimuth. Frustratingly, this can also change over time as decks are poorly or improperly maintained. Playing tapes back on a deck with an azimuth that is even minutely off from the source deck can make them sound milky, washy, muddy, or bright. The only way to correct for this in playback, historically, is to get a deck with what's called "azimuth adjustment." As you might imagine, these tend to be higher-end decks such as certain models made by Nakamichi. You can see people arguing at length over which deck is the best for this purpose.

If you aren't looking to produce crazy high-end remastered/restored editions of these cassettes, perhaps it won't matter as much to you, but I bet it will make a significant difference in the clarity and intelligibility of your recordings. And if you're going to digitize these only once for all eternity, I think it's worth it, especially if money is less of an object for you.

I have a Nakamichi DR-1 which I picked up for a song on Craigslist, and it's been absolutely amazing. There are "better" Nak decks out there (see my link above) but you can generally find one of these for a reasonable sum. Just try to go in on one that looks (at least to the extent that you can trust) as if it's been well-maintained and kept in solid running order.
posted by mykescipark at 10:09 AM on December 2, 2015 [4 favorites]

You could pick up a Zoom H1 for about $100 (and a big microsd card). It's an excellent stand-alone audio recorder, and will output to WAV or MP3. Find a high quality tape deck as recommend by people further up the thread, and connect the Zoom to the tape deck.

Using a Zoom will mean you don't have to fool around with audacity or worry about your computer going to sleep or whatever.

Plus at the end of the conversion project you'll have a high quality digital audio recorder if you ever need to do more interviews.

You might also think about getting a couple of external hard drives to copy your digital files to. Put one in a safety deposit box and one in a fire safe.
posted by gregr at 10:59 AM on December 2, 2015

I would actually check with an archival expert in this case. I did tape-to-digital transfers (untrained except for what I could glean from the internet) for a university department in the early 2000s. About 80% of the time, everything was fine and easy and straightforward. But 20% of the time things got complicated, and maybe 5% of the tapes--especially ones that had not been played at all since their recording--were destroyed in the process of digitizing. As in, you get one try at this tape because the emulsion is going to crumble off the reel as it unfurls. Knowing how to identify the problem reels was not always straightforward, and some material was lost (heartbreakingly, even though these weren't extremely valuable materials). If you want extreme care taken and have a low tolerance for error, go to the experts.

William Basinski made art out of this process, btw. If you like moody ambient music, check out the Disintegration Loops.
posted by late afternoon dreaming hotel at 11:20 AM on December 2, 2015 [3 favorites]

These are all good points, and I would echo them with two more thoughts about doing this:

1. It's good to plan that this may be the very last functioning of each cassette. Make sure you've checked your set up with a test tape to check everything works before doing it on an actual tape.

2. Understand that the tapes are likely be weak mechanically, so I would try to refrain from stressing them- such as rewinding them with a tape deck to the very end- the stress from the final 'thunk' might break the tape or pull it out of the reel. My old Onkyo deck had a pretty strong motor. (This isn't fatal, but it does mean you'll have to repair it, which adds time to the process, and is a even more difficult if the cassette isn't held together with screws- you'll have to carefully cut it apart and install it in another shell.) So if a casettes is already at its end, just tension them manually with a finger. Also, if the deck wants to autoreverse at the end of a side, you might want to try and circumvent that process as it waits for her tape to stop turning in order to sense to reverse. This again puts stress on the tape.

I digitized a 40 year old tape of my wife as a five year old, and immediately after doing so, the tape came off the reel and was out of commission. I was lucky enough to have gotten it right, as another stab at it would have needed a repair first.
posted by MacChimpman at 1:47 PM on December 2, 2015

Hit thrift stores and look for an old 16/44 or 48, or even a 24/96 high end recording interface. I see these a LOT now. Old TC electronics, motus, m-audios, you name it. Don't pay more than $20. These have BEAUTIFUL preamps/ADC converters and usually cost thousands when new, but no one cares now because they're not 24/192 or even higher with all the latest connections. It will probably be firewire, you'll need a computer with fw400 or a $4 adapter card. The best recordings of this sort i've gotten were from a cheapo dented up late 90s MOTU rack mount interface. They sound noticeably clearer and better than any other setup i attempted.(and it's not an EQ or colored sound thing, it's an SNR and noise floor thing)

Now hit craigslist, and look for your local audio gear facebook swap group. Maybe you'll luck out at the same thrift stores, maybe you wont. Nakamichi was a good suggestion, but there's other good high end decks like tascam and certain sonys. You don't need the best one ever made, basically anything in this list(notably the sony ES stuff which should be cheap) will do what you want very well.

Go to your local PC recycling center and ask if they have any rack mount power conditioners. Buy one, it should be about $20. Plug your recording PC, interface, and tape deck into it.

Buy some shitty tapes at a thrift store that are undamaged to test your setup with. Plug some headphone in to the interface. Set the levels, etc. Verify every function on the machine works and there's no slipping or nonfunctional stuff, which would likely be broken belts. The best would be to bring headphones and a tape with you everywhere you go to try a deck out including thrift stores. You might have a flat spotted rubber pinch roller(replaceable, but annoying. move on)

Once you'll full tested a machine and made a couple test recording, THEN you move on to recording them. Audacity is free and works fine for this.

Conver to FLAC, upload to a free dropbox account, burn to archival quality DVDs(do a google search) at the slowest possible speed and bury in a box in your closet.

The advice above about the tapes possible grenading at the end of the first play is real. Spend some time before you even put one in making sure the machine is playing smoothly without any noticeable wow or flutter, that one channel isn't louder than the other, etc. Do this with a commerical recording because your actual irreplaceable tape may not have been recorded well. Channel balance is something you can correct in post. Wow is a machine issue you don't want to deal with(and is likely the aforementioned pinch roller, belts, etc).
posted by emptythought at 2:27 PM on December 2, 2015

Nthing the advice to use a professional archivist if the interviews are valuable.

The magnetic oxide can flake off the plastic acetate base - we had some tapes and they had to be unwound and specially treated (baked in a special oven!) to bond the materials for this one last playback.
posted by jasper411 at 3:30 PM on December 2, 2015