Stock Radio Work-a-round.
Thread Starter
Racer
Joined: Sep 2003
Posts: 398
Likes: 0
From: Texas
Stock Radio Work-a-round.
I've been trying to put the radio in my 74 back to stock. It presently has an aftermarket CD player in a hacked up center console. I bought a new uncut center console, and finally found a stock radio to install.
It is from a 76 though. I've got the power and light and ground figured out, even got the speaker wires figured out, BUT, it has a 6 wire connector that is supposed to go to a "multiplexer", that I don't have and can't seem to find available. Is there a way to make this radio (am/fm stereo) work without the multiplexer??? Any semi-bubba fixes to make this work??? The radio doesn't appear to have a plug for the heat sink that goes behind the map pocket, so I guess that function must be combined in the multiplexer? I really would appreciate some help/advice here as I really would like to get rid of this aftermarket radio. I have done a search and not found the answers , please help!
Dusty
It is from a 76 though. I've got the power and light and ground figured out, even got the speaker wires figured out, BUT, it has a 6 wire connector that is supposed to go to a "multiplexer", that I don't have and can't seem to find available. Is there a way to make this radio (am/fm stereo) work without the multiplexer??? Any semi-bubba fixes to make this work??? The radio doesn't appear to have a plug for the heat sink that goes behind the map pocket, so I guess that function must be combined in the multiplexer? I really would appreciate some help/advice here as I really would like to get rid of this aftermarket radio. I have done a search and not found the answers , please help!
Dusty
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by Vmo
I really would appreciate some help/advice here as I really would like to get rid of this aftermarket radio. I have done a search and not found the answers , please help!
Dusty
Dusty
This is just a suggestion, but you know that Mid-America Corvette parts catalog has an exact stock replica of your stock stereo, that has a new modern digital tuner and aux hookups for an Ipod or MP3 player. It mounts just like your stock one, with the ***** through the holes, but plays like an aftermarket HU. It's pricey, but would give you the stock look, almost exactly, and you wouldn't have to track down 30 year old parts to put together a worn out stereo.
http://www.madvet.com/shop?frame=4.307.3486
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
The "multiplexer" term throws me. I purchased a '73 AM/FM Stereo for my '71 coupe last year (the previous owner scrapped the original for a Kenwood! Go figure....). It has a separate stereo power amplifier unit which mounts under the right side dash pad. It has a 3-wire lead and connector which hooks into a 3-wire lead/connector on the radio head. I believe that the three wires are "ground" and a signal side for each channel. The only electronics on the power amp heat sink are two power transistors and a couple of capacitors. If you have a 3-wire set coming out of the back of the radio head...that's them! If you don't have the power unit, I think you should be able to find one on e-bay for not too much $$$. This all assumes that your '76 radio is designed the same as my '73. Someone else may be able to tell you the "skinny" on that. By the way, the early '70's Corvette radios had 10ohm speakers--not that easy to come by today. You can probably replace the existing speakers with 8 ohm speakers, if you don't run the radio near max output (if you do, you'll fry the "peewee" power transistors). Good luck!
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by 7T1vette
the early '70's Corvette radios had 10ohm speakers
That's dumb. I don't even like some of today's Infinities, door speakers, that are 2 ohm. Most HUs won't like that.
Intermediate
Joined: Nov 2003
Posts: 33
Likes: 0
From: Windsor ON
multiplexer
If your radio is really from a 76 then the item you need is an amp (heat sink)
http://cgi.ebay.com/ebaymotors/Corve...20284178QQrdZ1
if its from an earlier year (69/70 ?) then it actually is a multiplexer that you need. In those years all mono AM/FM radios had a built-in stereo preamp but if you got the AM/FM stereo option they just added the mutiplexer which contains everything else needed to turn the mono radio into stereo.
You can differentiate by looking at the radio's case. If you see fins and something like the ebay pic on the side of your radio then it is an early one and the radio should work in mono without the multiplexer.
If all the sides are flat with no fins then it is a later one and the above amp will be needed to make it work. But beware these amps came in two versions one for mono radios and one for stereo (the ebay one is stereo)
The multiplexers are probably rare. In 1970 the AM/FM stereo radio was $278.10 which doesnt seem like much until you realize that it is almost the same price ($289.65) as the 454 option!
http://cgi.ebay.com/ebaymotors/Corve...20284178QQrdZ1
if its from an earlier year (69/70 ?) then it actually is a multiplexer that you need. In those years all mono AM/FM radios had a built-in stereo preamp but if you got the AM/FM stereo option they just added the mutiplexer which contains everything else needed to turn the mono radio into stereo.
You can differentiate by looking at the radio's case. If you see fins and something like the ebay pic on the side of your radio then it is an early one and the radio should work in mono without the multiplexer.
If all the sides are flat with no fins then it is a later one and the above amp will be needed to make it work. But beware these amps came in two versions one for mono radios and one for stereo (the ebay one is stereo)
The multiplexers are probably rare. In 1970 the AM/FM stereo radio was $278.10 which doesnt seem like much until you realize that it is almost the same price ($289.65) as the 454 option!
Last edited by tomzss; Aug 25, 2006 at 09:37 AM.
Thread Starter
Racer
Joined: Sep 2003
Posts: 398
Likes: 0
From: Texas
The plug on the radio appears to be the same as the one in the picture, but is there any way to avoid spending another 100 dollars to get this radio working?? Between the money I've already spent on the radio bezel, and the radio, I really hate to spend even more to get a crappy 70s sounding radio. I was hoping someone has some kind of a magic fix to make a cheaper alternative. Thanks for the inputs.
Dusty
Dusty
Intermediate
Joined: Nov 2003
Posts: 33
Likes: 0
From: Windsor ON
Sorry, a 76 radio will not work by itself.
If you know someone handy with a soldering iron you can tap into the preamp and then run it into any aftermarket amp. it wont be factory original but no one will see it either.
I can look at my schematics (which are at home right now) and tell you where to connect the wires if you want to try it.
Tom
If you know someone handy with a soldering iron you can tap into the preamp and then run it into any aftermarket amp. it wont be factory original but no one will see it either.
I can look at my schematics (which are at home right now) and tell you where to connect the wires if you want to try it.
Tom
Last edited by tomzss; Aug 25, 2006 at 09:59 AM.
Race Director
Joined: Feb 2005
Posts: 16,100
Likes: 17
Satelite 8 track..
Originally Posted by Vmo
I was hoping someone has some kind of a magic fix to make a cheaper alternative. Thanks for the inputs.
Dusty
Dusty
Some are cheap at $49....
Rich
Last edited by rihwoods; Aug 25, 2006 at 10:01 AM.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
There are companies that redo vintage car stereos with modern guts. I've been thinking about it for my dad's '54 GMC, I need to get the original tube radio out and see if it works first.
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,482
From: Southbound
Cruise-In II Veteran
Define "multi-plexer." 68-76 stock AM/FM units have one external transistor in a heat sink for the U69 and two of the them for the U-79 (stock stereo). If memory serves, each transistor has a three wire connector.
Purchase the assembly instruction manual (AIM) and study the diagrams of the stock installation.
Purchase the assembly instruction manual (AIM) and study the diagrams of the stock installation.
Le Mans Master
Joined: Oct 2000
Posts: 8,897
Likes: 1,357
From: Santa Ana CA
Originally Posted by tomzss
Sorry, a 76 radio will not work by itself.
If you know someone handy with a soldering iron you can tap into the preamp and then run it into any aftermarket amp. it wont be factory original but no one will see it either.
I can look at my schematics (which are at home right now) and tell you where to connect the wires if you want to try it.
Tom
If you know someone handy with a soldering iron you can tap into the preamp and then run it into any aftermarket amp. it wont be factory original but no one will see it either.
I can look at my schematics (which are at home right now) and tell you where to connect the wires if you want to try it.
Tom
I put the JBL amp in when I had an aftermarket stereo. The stereo was a piece of junk and even with just a tone control, the "new" "old" mono (in 4-channels) sounds far better than the aftermarket stereo did.
While I was in the radio, I added a wire to the "on" switch that would also send 12 volts to trigger the amp aleviating the need for a separate switch.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by toddalin
Exactly what I did on my '64 radio. I have a 4-channel JBL amp mounted under the passenger seat and when I did this modification a couple weeks ago, the old radio sounded far better than it ever did. The old power stage was making all kinds of noise and hiss, but the preamp stage is very clean.
I put the JBL amp in when I had an aftermarket stereo. The stereo was a piece of junk and even with just a tone control, the "new" "old" mono (in 4-channels) sounds far better than the aftermarket stereo did.
While I was in the radio, I added a wire to the "on" switch that would also send 12 volts to trigger the amp aleviating the need for a separate switch.
I put the JBL amp in when I had an aftermarket stereo. The stereo was a piece of junk and even with just a tone control, the "new" "old" mono (in 4-channels) sounds far better than the aftermarket stereo did.
While I was in the radio, I added a wire to the "on" switch that would also send 12 volts to trigger the amp aleviating the need for a separate switch.
Wouldn't happen to have some diagrams or schematics you could post huh?
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Originally Posted by Kalway
First time I've ever seen anyone want to go BACK to the original stereo. If I really wanted the stock look I'd do as suggested earlier and get the midamerica modern replica.
And the Amp was still sitting behind the pass side dash
It doesnt sound like the Kenwood that that was in it when I bought it, but its stock
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by Bob Onit
I did
And the Amp was still sitting behind the pass side dash
It doesnt sound like the Kenwood that that was in it when I bought it, but its stock
And the Amp was still sitting behind the pass side dash
It doesnt sound like the Kenwood that that was in it when I bought it, but its stock
Maybe I'm too new fasioned, but I love the aftermarket stereo I installed. Sounds great. Doesn't look stock, but sounds wonderful.