A Madman’s Quest to Build a DIY Tape Recorder/Player

Compared to a modern MP3 player, which is fully digital all the way down to the storage, the tape decks of the past are ridiculously complicated. When the Compact Cassette (the standard “cassette tape”) first came to market in the 1960s, digital audio was still a pipe dream. Suitable analog-to-digital conversion was within sight, but affordable storage wasn’t. So, the public turned to cassettes tapes with their complex electromechanical recorders and players. Because he seems to be some kind of masochist, Igor Brichkov is on a quest to build his own DIY tape recorder/player.

Because he still has some regard for his own sanity, Brichkov seems to be focusing solely on the electric and electronic circuits. He isn’t attempting to recreate the various winding mechanisms. That’s probably for the best, because those mechanisms are notoriously temperamental — even in production tape decks. Instead, Brichkov is using the mechanisms from an old tape with his own electronic circuits.

Those circuits broadly fit into two categories: playback and recording. On a production tape deck, there would likely be more intermingling between those in order to cut costs. But in this case, Brichkov kept them mostly separate and easier to understand.

The two most important components here are the recording head and the playback head. Brichkov chose to salvage the playback head from an existing tape deck, but constructed his own recording head. That is essentially just an electromagnet. As voltage from the audio source signal passes through, the recording head produces a magnetic field that varies in the same way. Run a magnetic storage medium, like tape, nearby and it will receive a magnetic imprint of the audio. The playback head then does the same thing in reverse to reproduce the audio.

While that concept is easy to understand, the actual execution required a deep dive into analog signal processing. Brichkov relied on op-amps as pre-amps to increase the amplitude to something usable, but he also had to include features like AC bias mixing with the input signal. That’s in addition to the recording and erasing features, as well as a VU meter made up of eight LEDs to provide rudimentary level visualization.

Brichkov feeds the pre-amp output directly to a wired amplifier, but he connected a Bluetooth receiver module to the input side. That lets him send an audio signal from a smartphone or tablet for recording. The components are still on strip boards, but we’ll be interested in seeing where Brichkov takes the project from here.