Putting New Into The Old – A Phonograph Upgrade.

[smellsofbikes] recently came into possession of a 1970’s “stereo radio phonograph” cabinet consisting of a vinyl record player, AM and FM radio, and eight track tape player. The radio worked, the turntable didn’t sound too nice, and the tape player didn’t work at all. A new needle fixed the turntable, but the eight-track was in bad shape. So he replaced the tape player with a BeagleBoneBlack which plays streaming internet radio.

Hopefully, this fix is temporary, since he has carefully disconnected the tape player connections in the hope of fixing it soon. The swap out involved a fair bit of engineering, so he’s split his build log into several bite sized chunks. The first step was to set up the BBB, upgrade it and add in all the network and audio related stuff. Audio on the BBB is available only via the HDMI port, but [smellsofbikes] had a USB soundcard handy, so the next step was setting that up. He installed mpg321 – the command line mp3 player and set it up to play music streaming from somafm. Next up was getting some scripts and programs to run automatically during system bootup. The final part of the setup was adding a WiFi router as a repeater connected to the BBB via an ethernet cable. He could have used a tiny WiFi USB dongle, but he already had the router lying around, and he wanted to dedicate USB to audio functions alone, and use the Ethernet port for Internet.

He then worked on identifying the wires that go from the tape player to the amplifier, spliced them, and hooked them up to the audio sound card on the BBB. With this done, the upgrade was more or less complete – the system played streaming music and stations could be switched remotely (via SSH to BBB). [smellsofbikes] reckoned it would be nice to use the existing controls in the phonograph cabinet to control the internet streaming music, instead of controlling it via a remote computer. The cabinet had 4 indicator lamps that indicated which track was being played and a button to switch between tracks. He removed the old indicator panel and put in a fresh PCB, designed in KiCad and cut on his LPKF circuit board plotter. An aluminum knob machined out of hex bar-stock works as the new track change button. At this point, he called it a wrap. The BBB and Asus router go inside the cabinet, and the old (non-functional) tape player is put in place. Quite an interesting build, and we look forward to when he actually gets the tape player working. [Alan Martin], aka “The Most Interesting Engineer In The World” has told him that “it is a moral imperative that you repair the eight-track and get it working”. [Alan] has promised to send [smellsofbikes] a suitcase full of brand new, still in their plastic wrappers, eight-track tapes when he gets it working.

28 thoughts on “Putting New Into The Old – A Phonograph Upgrade.

  1. Those 8 tracks will self destruct in one playing, if they have foam pressure pads. The last ones were real cheap.
    Save your good vinyl for another player. That’s a cheape cartridge not a magnetic pickup.
    Why a micro there is room inside for an old PC.
    Soma FM!

  2. yeah, the 8-track is not worth anything. even for history value, its worthless.

    I grew up using 8tracks – it was my first recordable system. as bad as cassettes were, they blew away 8tracks.

    those things could not die fast enough. please don’t bother with it. some old stuff is cool. 8 tracks are not in that class. there’s just nothing good about them.

    what might be funny is to open up an 8track tape, put in something that uses nearfield or proximity and acts like a trigger to turn on specific things. insert 8-track A and it plays music from artist A. insert B and you get B. each dummied up take could send out some unique id burst (using some radio format, anything could work here) and some sensor would pick that up and basically just juggle the playlist corresponding to the ‘tape’ id that was sensed.

    THAT might be a neat hack!

      1. Radio stations did not use “8 tracks”. We used carts — same shape, different setup, higher fidelity, and actually older.


        Imagine that the same 1/4″ tape had only two tracks (left and right) and a signal track. You had higher fidelity (I speak from experience — I recorded about 60 ads in the 1990s) and some nice features for the time.

        Eight-track? How DARE you…! (flaring nostrils ahoy)

      2. I’ll confirm what [pseydtonne] said. We used “carts”, short for “broadcast cartridges”. Any exclamations from visitors of “duuude, you play 8 tracks?” were immediately countered with “duuude, nooo we don’t!”. Properly aligned and using Dolby, a fresh cart in a good machine could produce near-CD quality audio. Even on their best days, 8-tracks could only try to sound like a cheap cassette tape.

        That said, I still enjoy playing 8-tracks at home (something about the “ker-thunk” sound from the solenoid is magical), and replacing the rotting foam pads isn’t all that difficult in most 8-track shells. The worst that goes wrong with most 8-track players (unless something gets jammed in or a rotten foam pad gets smeared all over the insides) is that the belt will fail by breaking/elongating or by turning into goo (depending on what the belt was made of). Replacement belts are readily had and even cleaning belt goo off the capstan isn’t particularly difficult.

      1. There used to be commercial adapters that routed the headphone out of a CD player to an electromagnet in a cassette tape shell. Along with some gears to make sure the spindles moved in unison, which was necessary to fool some players’ detection of end of tape (or broken tape). I’ve never seen an 8-track version, but I’m sure it could be built.

        1. I was thinking about doing this: pulling out the cartridge from one of those cd-to-tape adapters and driving it with a gumstix reading mp3’s off an sdcard. I have all the pieces. But this had to get finished and running for a PI party, so fancy stuff got tossed in pursuit of minimum robust functionality.

        2. RadioShack (and others) used to sell a cassette player that would be plugged into the 8-track slot.
          I’m not sure how it moved the signal from the cassette head to the 8-track head, but 8-tracks capstan drive drove a pulley to drive the cassette hubs. I think it bled a small charge off of the track change sensor to power the amplifier for the cassette head.

      2. Use another 8 track head aligned with the active head. Feed as much signal into it as to match the volume of a loud tape. This is what seems to be in the cassette adapters. Also what is in card readers when you swipe.

  3. As a footnote, 8 track openings are almost exactly the same size as desktop drives. I am partway through a build which I originally intended to stuff a harddrive through the original 8-track fascia (as in my Magnovox unit the 8 track hardware was removable from the rest of the head unit, leaving plenty of empty room for a raspberry pi, a small router, and misc other hardware, not the least of which is a cheap TOSlink to RCA module (for the audio out from my tv).

    Just some thoughts. I may end up gutting mine out and installing some ventilated bays for a couple game systems, and storage for all the stuff that goes with it. You can get these cabinets at the big warehouse Goodwill locations for like 5-10 bucks frequently (I have 3 of them now of varying ages and conditions) or sometimes on Cragslist for free. Great project cabinets!

  4. Ahh, nostalgia; I learned to sing and listened to really old music in front of a stereo that looked just like that as a small child. If I ever have room, I want one; not to use as is, but to just keep the shell and replace all the innards with some quality parts. Good turn table, cassette, hacked up 8 track recorder, mp3/ogg/flac/streaming, and some nice 8″ low-mid and electrostatic mid-high speakers. Just out of nostalgia.

    Considering the price I saw one at in a thrift shop (over $100) I guess I should be glad I tend to live in small apartments.

  5. One thing the 8 track could do that escaped the greater market was Quad, real Quad 4.0 not a matrix or CD4 (had nothing to do with CD’s) on vinyl. I have a couple around somewhere and the extra head or two.
    Phillips botched what would have been the best Quad for the time. A small company came out with a 4 track Quad cassette about 74. It wasn’t that expensive, play model $100 record-play $150. Since there was no compatibility Phillips said NO! It was another 10 years or so when the 4 track portable studio was allowed with a normal stereo or 4 track switch to be compatible. Most of those 4 tracks would only mix down to 2 RCA jacks. Still no Quad.
    Most major labels mixed Quad versions of some great music from that era.

  6. I have been keeping an eye open for a ‘Hi-Fi Console’ myself for a similar project (would prefer a tube unit but aesthetic condition and price are mitigating factors). I just find today’s cheap Chinese crap unappealing on every level, from looks to sound quality. Some of those consoles sound quite good despite being moderate wattage, and I love the look.

    Picked up a pair of 70’s Acoustic Research AR4’s at a flea market for $10 and after a $20 surround repair they are amazing! It amazes me that despite all of today’s technology most people have not really experienced good stereo sound. Additionally, with today’s low cost of storage I don’t understand the continued appeal of the mp3 format.

    As for the 8 Track, I say let it go… There’s nothing there worth saving.

  7. I’m not sure it’s all that fun and interesting to have 1970’s era particleboard in your house, it was probably soaked in a lovely mixture of formaldehyde and other organic solvents and no doubt emits a foul smell.

  8. When you get the 8-track player fixed you can put the BBB in an 8-track shell along with a write head. The challenge will be the power. Maybe you could put a couple metal pads on the outside of the shell and create contact points for them to mate with inside the player.

    Then you have an authentic old stereo AND a BBB! Probably not any more practical than just leaving it as is or using the aux-in (if there is one) but more fun to show off!

    1. No aux-in, alas. I’d like to eventually swap the switch, that right now is ‘phono/am/fm/tape’ for a five-position rotary so I can add this in, if/when I get the tape working.
      I’m wondering if there’s enough room for a bbb in an eight-track cartridge. Were I to do that, I’d probably power it inductively, as there’s excellent access to one face and two sides of the tape when it’s in the player. (Would it erase tapes, if it turned on while one was playing? Maybe a Secret Message Will Self-Destruct mode…)

      1. I like the self-destruct mode more, the more I think about it. There are already two contact switches that signal if a tape is inserted, and if it’s recordable. A third one could signal if the tape has a little chunk cut out on one edge. If it doesn’t, it plays just like normal, but if it does, the inductive coil turns on and nukes the tape while it’s playing, so you only get one read out of it.
        Of course, this is inverse security: it would play repeatedly on anyone else’s eight-track.
        but if I wait long enough, there won’t be any more operational ones, and then my plan will be awesome.

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