Delco 8-track with Modern Amp + Speakers? *

Discussion in 'Car Audio, Electronics & Security' started by JohnnyZ, Jan 9, 2012.

  1. JohnnyZ

    JohnnyZ Veteran Member

    Sep 2, 2010
    Currently my ’78 Z28 does not have any audio equipment installed. I’m looking at finding an old Delco 8-track and then wiring in some off the shelf speakers and maybe an inexpensive amp.* I’ve been reading up and it appears the old Delco’s are 4 ohm while modern electronics is 8 ohm.
    Where should I start to look to get this all done? Has anyone done it? Do I just need a few resistors of a fuse and all will be well? Will my local Audio guy know what I’m talking about?
  2. 1971CamaroGuy

    1971CamaroGuy LS Swapped 1971 Camaro

    Oct 31, 2004
    The cheapest way to do it is to get a amplifier with hi-level inputs and wire the speaker out from the radio into the amplifier.....then run your speakers to the amplifer. Just get a set of good 4 ohm speakers that are matched to the amplifier.

    Most modern amps can do this,For digital music, you can use an IPod, IPhone, or mp3 player through an fm modulator.

    just keep in mind the limitations is going to be the 8-track unit itself.
  3. Twisted_Metal

    Twisted_Metal Administrator Staff Member Lifetime Gold Member

    Feb 26, 2004
    Bloomington, MN
    ^ That should work.

    Many FM modulators are mono.
    I tried two different ones and they were horrible.

    I now use a cassette adapter with my MP3 player and it actually works quite well!
    WAY better than a cheap FM modulator. :D

    I don't know of anyone making an 8-track to MP3/CD adapter.

    Unless you have someone add a plug interface to the head unit..... You might have to take this route for an external player.


    ;) :crazy:
  4. Gary S

    Gary S Administrator Lifetime Gold Member

    Apr 14, 1999
    Bismarck, North Dakota
    All the old Delco radios I've worked with, AM, AM-FM, 8 track, or cassette have 10 ohm outputs on their amps, not 4 ohm. Using 4 ohm speakers would get you dangerously close to damaging the output amplifier from excessive current.
  5. JohnnyZ

    JohnnyZ Veteran Member

    Sep 2, 2010
    Alright - so the Delco is 10 ohm out? What type of Speakers do I need? I don't even know what an OHM is.
  6. JohnnyZ

    JohnnyZ Veteran Member

    Sep 2, 2010
    I'm not worried about the iPhone. I plan to pick up a pile of 8-tracks :crazy:
  7. Gary S

    Gary S Administrator Lifetime Gold Member

    Apr 14, 1999
    Bismarck, North Dakota
    The only 10 ohm speakers I've ever found in the past 40 years were the GM Delco speakers. If you can't find 10 ohm speakers, use 8 ohm ones.
    And, if you put a separate amp on the old radio, the speakers need to match the amp, not the radio. Then, you need to match the input of the amp to the 10 ohm impedance of the output of the radio.
  8. 2ndgenhunter

    2ndgenhunter Veteran Member

    Mar 19, 2010
  9. jroach

    jroach Veteran Member

    Apr 9, 2007
    petersburg MI
    delco output

    i just talked to a guy at car stereo one. he told me there is no way to modify the 10 ohm out put of the delco radio to work with any modern amp he also told me that they used common ground on the speakers so i could not use an amp because of that also. is this true? sounded like bs to me.
  10. Bikefixr

    Bikefixr Veteran Member Lifetime Gold Member

    Mar 13, 2006
    Your audio guy is clueless.GM hasn't used a common speaker ground since the 60's. And even if they did, so what? You will be rewiring modern equipment and speaker in, and normal grounding now applies. I have done EXACTLY what you want to do and mine works great.

    The factory radio speaker outputs can't be wired into a modern amp directly. The impedence (resistance) is to high. No big deal...we are using a small converter to take your high impedence output and converting it into a modern low impedance output.

    I used a PAC adjustable line output converter. It takes your speaker outputs (pos and negative) and drops the voltage to a manageable level and impedance. Then you connect to an amp with standard RCA cables. Connect amp to any 4ohm speaker you want.

    The Delco 8-track is much better than people give it credit for. The FM section is very good, and the tape section is also very good. 8-tracks got a bad reputation mostly because people don't take care of them. You can make tapes that outperform a cassette. I record my own and you would be amazed at how nice they sound. Barry's 8-track repair in AZ tweaked my DELCO player and my Marantz home recorder. He can also add line-inputs to your DELCO. The other option is this: PAC also makes a line-level switch. So if you want to play your I-pod through your factory system..skip all those crappy FM modulators. The switching adapter has 2 inputs and 1 output. When it senses a switches that into the amp. I use one of these to switch between my in-dash DELCO Am/FM and my console mounted DELCO 8-trackplayer. Seamless and sounds great. The PAC adapters are between $25 and $35 depending on what you need it to do.

    Go to Ebay:

    This is a $22 widget that connects your factory radio/8track to any aftermarket amp you want, 2 or 4 channels. It turns the amp on and off with a current sensing wire.

    Now get one of these:

    You need an I-pod to RCA cable. Connect cable to I-pod, the RCA's to the widget above. This allows you to boost the output of the I-pod high enough to drive the amplifier. Volume up/down via I-pod built-in controls. This widget goes into a signal-sensing line-level switchbox. I use a PIE SW-2. When the I-pod is on..the box sends the signal to the amp. When you turn the radio head unit on it turns the I-pod off and send the radio signal to the amp.

    Sounds isn't. It's just a matter of dropping the signal from the radio, boosting the signal from the I-pod , then switching from one to the other and sending it to the amp. I wired mine up an a couple hours. Love it. Looks totally stock, but I have the in-dash DELCO, underdash 8-track, and a hidden Xune...driving a sweet ADS 2 channel amp into an Infinity 6x9 coax in the rear package shelf and an Infinity 4x10 coax in the factory dash location.
    Last edited: Mar 10, 2014

Share This Page