MEI Amplifier Wiring Question

I got a bunch of car parts and stuff the other day for free, and there was a nice pair of 150 Watt Sony 3-way 6 X 9 inch speakers and a circa 1980's MEI amplifier in good condition:

The label says:
MEI
Mobile Audio Systems
Model: PA705H
40 Watt Power Amplifier
DC 12 Volt Negative Ground

Made in Korea (I presume South Korea)
Ground Each Speaker Individually (I used the Stock Ford 2-wire harness +-)
Do Not Connect any ground wires together. (No problem there)

The speaker wires are paired by color and identified:

Input side:
Left = Blue/Blue (with black stripe = negative ground
Right = Green/ Grn/black stripe

Then two with RCA jacks (MP3/Cassette input connectors)
Left = White (Low Input)
Right = Red (Low Input)

Output Side:
Left = White/White with black stripe
Right = Gray/Gray with black stripe

Then 3 other wires with no tags:
Red (It's cut where the fuse probably was, because there was a red wire in the box of junk, with a fuse holder)

Orange = ??? My guess is a remote switch in the dash to turn it on/off

Black = ??? Amplifier Ground???

The thing is black with the red MEI logo and measures about:
1" thick
4" wide
5" deep

and has side mounting screw nuts on each side, recessed in the case.

I searched on the WWW and found several forums guessing at the parent company. I searched for wiring diagrams, and no hits.

If anybody recalls these small amps, would you post what you know about the wiring. Most times these kinds of amps get mounted in the trunk, so if the driver wants to boost the sound up from whatever the radio/MP3 or whatever can produce (sound volume power), they need a dash-mounted switch. There's no switch on this unit, so it must have stayed in the car.

All the tuning/tone/volume has to come from the radio/etc.

My radio/cassette is a Toshiba and has similar RCA jack wires with the female end. These are male on this Amp.

So far the best guesses for the original firm was:

Matsu****a Electronics Industries (MEI) - Japanese
Mansoor Electronics Industries (MEI) - Taiwanese
JN MEI a division of Phillips Electronics - Taiwanese

and MEI is a common street name throughout China, Taiwan and both Koreas.

I tried searching with "mobile amplifier wiring diagram" (and variations of those keywords) as well as MEI, Mansoor, and combined with one or any combination (12 combos) and no results.

It was sold through a big US distributor via CostCo and many car audio shops and parts stores.

The Orange, Black and Red wires are the dubious ones. If I do it the wrong way, it's toast. I think I'm close to having it right, but better to know from someone else who knows.

 

Aw Heck light that candle and see if she takes off.

 

They don't get any cheaper than FREE. I think the ones are a couple C-notes. No candles until some body pipes in.

 

Dang I'm glad I hid under that chair.

 

You're safe. I love listening to the Jazz greats and hearing them 'talk' to each other with their instruments. I love my eardrums a whole lot, so its not the loudness, its the clarity that the amp would deliver. And once you've heard the best Mexican Mariachi bands, you don't want to miss a note. I was raised at the right time in music's evolution, and its almost criminal that good jazz isn't around much on the radio waves. Spoiled rotten. My parents and I sat from 7 PM to 4 AM in the French Quarter back in the early 70's listening to Al Hirts in his own club, jamming with musicians from the other clubs. the place wasn't packed either. What a night! Then we went to Pete Fountain's club the next night and more jamming all night!

Dad played with Oscar Petersen in WWII, dual pianos, and he sent dad a copy of the recording. Awesome times.

 

It's not specific for this MEI unit, but its a good generic diagram anyway, and they've even got a downloadable installation movie:
http://www.crutchfieldadvisor.ca/S-qfA9bQt0374/learningcenter/car/amplifiers_wiring.html

http://www.crutchfieldadvisor.ca/S-qfA9bQt0374/learningcenter/car/amplifiers_movie.html

Still looking though...

 

1767 Car Amps to choose from! Sheesh!
http://ampguts.realmofexcursion.com/

 

Edmunds have a heck of an unbiassed list of tech on car audio systems:

http://www.edmunds.com/ownership/audio/articles/index.html

 

I'm gonna open up the box and trace the circuit. Heck there might be a color-coded wire diagram inside.

 

New and Refurbished Car/Home MP3, Audio, Video

I figured I'd give it one last shot (the extra mile) and found a goldmine of goodies!

http://www.sonicelectronix.com/

Check out their Liquidation Station menu! High end equipment at 1/3rd of Walmart prices!

They've also got a Discontinued list, which is useful if you don't want to buy something that's already off the market, when you go shopping for some good equipment.

Some good tech info on speaker sizing too.

 

Old car and home stereo equipment manuals, anyone?

http://www.stereomanuals.com/index.htm

 

A Stereo School for Cars!! ??

Holy smokes! Check out the sound system in this Caddy Hearse (uh, Station Wagon!) You'd never need Q-Tips again! Melts the wax out of your ears!

http://www.stereoschool.com/okc/gallery/showcars.php?start=10&p_f=0

 

Got The Wiring Solved!

I have a Love/Hate relationship with anything Microsoft, like most folks, so I never used their "Live Search" until today. Google does a lot of stuff, but it gave me mainly Commercial results. I wanted down and dirty circuit info.

The Fairmonts offered a Premium Stereo option that came with an amplifier hooked up between the speakers and radio, and mounted under the middle speaker cavity under the dash pad. This little unit fits Perfectly! I'll cover the speaker holes from underneath to keep the dust and spilled coffee off the amp, and since I just finished wiring the radio, I can add a couple connectors and in she goes!

It's only 40 watts of power to 4 channels (speakers). The beauty is that I also got those Honkin' 150-watt Sony rear (6" X 9") 3-way speakers (Base, Mid-range and tweeter in each one) and I've got nice 40-watt tweeters in the front. The ones I installed would work fine, but I had to fix a couple of small holes with finger nail polish. They're 150 watt units with only a base and mid-range. That means you miss stuff on 2 of the 4 channels.

Here's what I did:

1) I opened up the unit carefully - a couple of dried potato bugs fell out.

2) I traced the 3 dubious wires; Black, Orange, Red (non speaker, non RCA jack wires)

* Black goes to a solder joint marked ' - GRND' - straightforward

Red and Orange go to a blackbox thingy I didn't recognize. The Live Search let me search by component number and find a site with the FREE Data Sheets (electronic layout, circuit board connectors, etc.)

It was an NEC MR-301 12H (25 amp) relay. Looked at the hookup, and the circuit board solder and I knew from reading the pages on Headlight relays which was which.

* Red is the fused power line.
* Orange is the Amp's On/Off remote switch power.

If it's not on, the radio runs the speakers, if it's on, you get fuller sound, even at lower volumes.

I couldn't believe that there are 1,500 watt amps for cars. No wonder kids keep asking you to repeat! WHAT from too many WATTS! Nuts.

If you're lucky enough to find a small, after market amp at the junkyard or a garage sale, I think this method of solving the wiring codes will work.

By the way, this same relay is used in Power door locks, power antenna circuits, and lots of other sensor circuits.

Here's the Intregrated Circuit Datasheet sheet site:
http://www.datasheetcatalog.com/

This is the 'Other Manufacturer' page (NEC isn't on the main page above):
http://www.datasheetcatalog.com/other_manufacturer.html

This is this Relay's datasheet download page:
http://www.datasheetcatalog.com/datasheets_pdf/M/R/3/0/MR301-12H.shtml

Now we can R&R most anything.

EDIT: Just to keep it in one page:

And then I found this site with the exact circuits! These are the components (IC - Integrated Circuit), but the datasheet shows a typical circuit board layout. If it broke down, I could take it to a repair shop with these documents and have them fix it. The new amps are much bigger! How the heck could you run a 1,500 watt amp? That's 150 amperes on a 12 volt circuit! No wonder they went to 42 volt systems!

http://www.alldatasheet.com/view.jsp?Searchword=MEI

That's another AMEN to that mystery!

 

And then I looked at the Toshiba Cassette/Stereo deck. I thought it was like a Factory Radio, at about 10 watts. It's 50 watts, all by itself. The amp is 40 watts.

I'll keep it for the next car.:2_thumbs_up_-_anima

 

Great info Norman now I can look for a amp to go along with my new Panasonic stereo.