Adri's Audio » How to digitalize physical formats

Adrianna Oliva

DAPR 4085

September 8 2026

Cassette Restoration: A how-to

Picture this; you're an audio engineer starting in a new producer role. Entering the studio feels like traveling back in time. The retro looking room has pictures on the walls similar in style to those of the 1980’s, and the mustard colored walls have acoustic foam boards of various shapes and sizes. Sitting on the desk is a Wheatstone AudioArts A-50 analog broadcast console, which was discontinued in the early 2000’s. Looking around at all this equipment, it really feels like time stopped in this room.

What's more; in the storage closet you find boxes upon boxes of old cassettes and reel to reel’s dating all the way back to 1975. But just sitting in boxes, these stories will go unheard to the new age of streaming services and digital audio. To let future generations enjoy these ancient conversations, audio engineers take these analog relics and convert them to digital format using various procedures and skills, outlined below. This paper will focus on cassettes, though reel to reel restoration is a very similar process (just different machines).

To understand restoring, you must first understand how a cassette stores audio. It is important to note that mechanical audio signals going into a microphone are converted to electrical signals. Two magnetic coils of tape sit inside a cassette, where the electrical signal is etched into the tape. Those same etchings in the tape become audible during playback, which is how you hear the signal recorded to the cassette.

There is a caveat to repeated playback; over time, the magnetic tape inside a cassette will erode or the cassette itself can get damaged. Even the National Archives and Records Administration recommends digitalizing tapes older than 15 years. Sometimes when played too much, reels of tape can magnetize together and cause an echo-like effect during playback. Storing a cassette in the wrong environment can even add to a recording's demise. Issues like these make it extremely important to restore tapes and put them in digital format. This way, the audio can be played back as many times as desired without ruining the quality of the recording.

Here's the question now; “How do I take this analogue tape and convert it to digital?”. It's actually pretty simple, first you need a cassette machine to playback your tapes. The cassette goes into a cassette player, whose output goes to the input of your interface, goes into your computer, and then into your digital audio workstation (or DAW) of choice. This probably sounds confusing if it's your first time hearing about signal flow, so think of it like this; cassette > cassette player > interface > computer > DAW. It's actually recommended by the International Association of Sound and Audiovisual Archives to digitalize at 24 bits and at least 48 kHz, so make sure your session has those settings when you create it! Once in your DAW, create a stereo audio track with whatever input is being fed by your cassette player. For this example, let's say we have the cassette deck via 2 xlr cables going into inputs 1 and 2 on your interface. You would select input 1 and 2 on your audio track.

After this, record enable and input monitor the track so you can hear what is being recorded, and hit record in your DAW before actually playing the cassette. At your cassette player, you now want to fast forward and then completely rewind your cassette. This makes sure it starts the cassette at the very beginning when you hit play. As long as the routing is correct and the track is recording when you hit play on the cassette player itself, you should start to hear the magic happen. The machine reads the magnetic tapes in your cassette, and the output of the cassette player will record directly into your DAW. Let the machine play the cassette all the way through, ensuring all parts of the cassette are recorded into your workstation.

Once the cassette is digitalized, the real fun begins. The process of preserving the tape is turning it to digital, but making it sound better is the process of audio restoration. When dealing with old audio formats there can be a variety of different artifacts affecting the sound of your preserved audio; crackles, popping, a hum or buzz in a recording, unintelligible audio, and so many other issues.

With clicks, pops, hum, or buzz, audio engineers typically turn to de-click or de-noise plugins to remove unwanted noises (Cedar, Reaper de-noise plugins, and Izotope RX-11 are examples of tools audio restorationists might use).The main goal of restoration is to clean the sound of a recording and make it more intelligible, while keeping the restoring as true to its original as possible. Basic equalization and compression (other types of audio processing) are likely to be utilized if an engineer sees fit for the restoration process.

The various restoration processes must be used with caution; too much processing can lead to unwanted artifacts or leaving the audio clearly processed. While the main goal is to make these old recordings sound as good as possible, tampering with the sound too much can take away from the “old-time feel” and make it obvious that the track was tampered with. So, while it's recommended to process your tracks as much as needed, make sure that isn't tampering with the final product of your restoration.

Understanding these processes could help you restore old formats dating back even before 1975. Conversations that have been lost in the airways for decades could be brought back to life by restoring cassettes. Or maybe a client has recordings of a relative that has passed. Bringing back these old conversations could provide a great comfort for the owners of the material, and spark interests for all the people who are likely to hear it once restored. Words shouldn't have to go lost in time when we have the tools to bring them back to life.

Works Cited

International Association of Sound and Audiovisual Archives. Guidelines on the Production and Preservation of Digital Audio Objects. IASA, https://www.iasa-web.org/tc04/audio-preservation. Accessed 8 Sept. 2026.

National Archives and Records Administration. “Machine-Readable Media.” National Archives, https://www.archives.gov/preservation/holdings-maintenance/machine-readable. Accessed 8 Sept. 2026.

How to digitalize physical formats

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