Vintage Car Audio Gets MP3 Input

[Nali] is fixing up a 1966 Rambler Ambassador and decided to give the audio a bit of an upgrade. Instead of replacing the head unit he added a connector for audio input. The method he used is simple, inexpensive, and allows the original unit to continue functioning as a radio. He cut the feed wires going to the volume knob and patched in a headphone jack. The jack he used has an internal switch that is meant to switch off a pair of speakers when headphones are plugged in. The jack will allow the original signal from the radio tuner to pass through whenever there isn’t a connector plugged in. It seems like this is easier on older hardware than it is on modern equipment.

This isn’t where his entertainment enhancements stop. [Nali’s] working on a 7″ in-dash Linux machine so keep your eye on his thread to see what he comes up with.

[Thanks Joel383]

20 thoughts on “Vintage Car Audio Gets MP3 Input

  1. Its interesting he states that the grounds differ from inside the radio to the vehicle ground, and in most cases that is correct.

    Solutions? Simple ground loop isolator? $7 at monoprice. Possibly may be able to snip the ground on the signal wire as well.

  2. “Keep you are eye on his thread?”

    Hey, I’m building a 7″ touchscreen carputer as well.
    Using a 60GB SSD for now. Biggest problem is getting a Linux-compatible FM tuner. I’m working on a dock for a slimline CD/DVD-rw that’s USB powered; it would be nice to pop that out to use with my netbook. I keep reving the idea though, so I may never finish it. Flip-up screen, removable, internal battery, etc. Also saw an earlier version of the radio input hack; I wanted to try it, but the stock stereo is showing its age (they don’t build ’em like they used to), so the cartainment system superseded that.

  3. Nice hack, in the old-school sense. Takes me back . . .

    I helped a friend do this some years ago on a ’66 mustang to add a CD player. The audio level at the volume knob wasn’t close to the headphones output, so it took some experimentation to find the best stage to connect the CD output for minimal gain- and impedance-mismatch. The ground loop problem came up then, too. Battery power for the CD (and not adding a connection between audio ground and vehicle ground) solved that to his satisfaction.

    Also, we didn’t use a fancy switch/jack either, just unplugged the CD (or didn’t use it) while playing 8-track. Yeah, he had an 8-track collection — and a recorder! I like this solution a little better, but my buddy was even cheaper than Phil here.

    And why the tape input instead of the radio, you ask? It was a stereo 8-track but a separate (in the same chassis) AM-only radio! You could get AM/FM radio in the car _or_ AM/8-track — or just AM for cheapskates.

  4. I did it in ’69 with my dads F85 Oldsmobile-Delco. 1/4 inch jack to a Norelco Carrycorder, the proto cassette. Unless you had an old Ford or AMC you couldn’t hack most portable stuff into a car’s radio. This was at a time when most tranys were PNP and positive ground design.
    The Norelco was cutting edge compared to 4 or 8 tracks. Mono of course, but HiFi and it had neg ground transistor design. Cars by then were all neg ground. Power was on the tip audio on the ring, radio was c/o on insertion.
    This hack is the best way to do this today. Most factory car radios have good performance and sound except for speakers. But they have little theft appeal too. Upgrade what can’t be seen, power amp and speakers. Then plug in a HiFi source of digital audio, no Mpee’s! That’s progress.
    Two years later that ’65 Olds got a stereo car type but portable cassette with 2 mounted under dash speakers so the radio with a simple lo-pass became probably the first 2.1 (sub)bass system in the world. And dad didn’t know it was installed!
    Lastly no computer card or TV tuner pod can compare to any decent factory or Pioneer tuner, most are intermod hell. You should hack the data bus on a Pioneer instead.

  5. if i was going for a carputer that small, i would get one of those car stereos like this one: if that’s anything like the one i was playing with at bestbuy, you push the button, face flips down, screen folds out, touchscreen.. awesomely mechanized. it already plays dvds but i’m sure one of you genius hackers could figure out how to interface it with the carputer, throw in a usb port, maybe some card slots, in the dash or something, of course, leaving the original unit just like it is, only figuring out how to utilize the touchscreen.. unless you’re planning on building a carputer that flips out like that, from scratch. that I would like to see.

  6. Nice! Way better than my fix, which was to retrofit my [does it matter?] with a really stupid and overly complex system using an inverter and a generic $100 stereo with remote.

    I meant to do the car computer thing, but never got around to it. So I just bought a generic all-in-one mini stereo with decent speakers at a pawn shop.

    I just ran the speakers to the backseat/bench under the carpets – the hardest part was stuffing the whole thing into a milk crate stuffed with foam and wiring the inverter in place of fog lights. Took about an hour and a half to do everything. The stereo in my car is original and has some collector value, so I left it alone.

    Apart from having to burn custom CDs to put five disks of “appropriate music” in, and the little issue of dropping the remote a lot, it works OK. The mediocre stereo plays .mp3s, so I have a lot of music available.

    I can’t “crank it up” to create deafness inducing audio levels, but the engine can do that all by itself. I can’t really drive it for more than an hour or two on the freeway without taking a break to relax the smile muscles anyway.

    Best of all, no one will try to steal the radio because it’s so damn old looking. It took about 10 minutes to change the inverter power connector over to spade lugs. I’d do this again.

  7. I m Nali .
    English is not my native so be nice with me . I m french . Just avoid slang and I ll understand ..
    What I did on my old Rambler radio is the result of knowledge .
    I really know electronics . Not too difficult , I m not proud of it . So what I did was after a lot of mesurement , cares , etc .
    If you don t know what you do , ask a friend .
    You may destroy your radio , your mp3 / ogg player or both .

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