I posted this as a question originally before the crash which led to how I ended up setting up my radio so I thought I’d at least throw out there the nutshell version and if there is interest I can answer questions and provide more info.
My goal was to utilize a factory radio for my 77 and add a console 8 track but also be able to use Bluetooth to link my phone. 70-77 radios and the separate 8 tracks, for those that don’t know, utilized one wire to each speaker (technically even though the rear speaker did have two) and used common ground instead of 78+ (and modern radios) for their speaker connections. They also required 8-10 ohm speakers which can be purchased but aren’t the “standard” anymore.
What I did was purchased a Bluetooth enabled amp made by kenwood (I believe others exist too) which was small enough to mount under my center console. Then I used a line output converter to convert the factory one wire output to two rca line level outputs that I could feed into my amp. I used two rca splitters so my amp “saw” 4 inputs, left front, right front, left rear, and right rear. The amp then fed “4” modern speakers. I say 4 in quotes cause I used one of the dual coil from speakers so technically that speaker plus two 6x9s out back. Anyway, the amp was now the deciding factor on what type of speakers were required so there was no need for 8-10 ohm speakers. The amp has a wired remote which I hid in my ashtray and switches between an rca input (radio or 8 track player) or push a button and the amp switches to Bluetooth and will stream from my phone.
I know this is real bare-bones on what the setup is but #1 like I said if there are further questions and interest I’ll be happy to answer and #2 I struggled to find any info saying something as simple as a line output converter would work so I figured if I post this someone might find it and know it’s possible to do.
Is it the perfect setup for a high output state of the art audio system? No. But for the average Joe, I think it works just fine.
