Nakamichi Amp replacement. Preamp or speaker level inputs NAK
03-17-08 | 12:57 PM
#1
Thread Starter
Lead Lap
Joined: Apr 2007
Posts: 522
Likes: 5
From: sc
Nakamichi Amp replacement. Preamp or speaker level inputs NAK Diagrams & PICS
I have determined I have a bad output channel on my drivers side front channel. I would like to replace the Nakamichi with an aftermarket 5 channel amplifier. I plan on removing the factory amp all together and replace it with an aftermarket one. I am not sure yet as I need to know what type of inputs I need before I can work on selecting a model. I can handle making the RCA connectors if need be.
It is on a 1998 GS(400).
Any input would be great.
I have attached the diagram just as a matter of documentation. This was from an attachment that Dan at tuning factory sent on to me.
My question is pretty simple:
Which type of amp do I need to get?
Do I need to get one that is set up for speaker level inputs?
Do I need to get one that is set up for preamp inputs?
Thanks,
BP
It is on a 1998 GS(400).
Any input would be great.
I have attached the diagram just as a matter of documentation. This was from an attachment that Dan at tuning factory sent on to me.
My question is pretty simple:
Which type of amp do I need to get?
Do I need to get one that is set up for speaker level inputs?
Do I need to get one that is set up for preamp inputs?
Thanks,
BP
Last edited by TRD911; 03-18-08 at 04:29 AM. Reason: 1998 GS
03-17-08 | 03:14 PM
#3
Thread Starter
Lead Lap
Joined: Apr 2007
Posts: 522
Likes: 5
From: sc
I know this could really be a question that is better asked on some audio forums.. Just so you know it has taken me the better part of the past weekend just to get my question together so that I know what I need to go forward.
The next question will be how do I tell what I got. I have an O-scope I can hook up and measure the voltages (input) and this might tell me what I have...
My speaker always works it just is about 99% less volume than the other 4.
It does sound very staticy as well.
This picture is of the input wires to the amp. Maybe the size will lead someone to a conclusion.
BP
The next question will be how do I tell what I got. I have an O-scope I can hook up and measure the voltages (input) and this might tell me what I have...
My speaker always works it just is about 99% less volume than the other 4.
It does sound very staticy as well.
This picture is of the input wires to the amp. Maybe the size will lead someone to a conclusion.
BP
03-20-08 | 02:35 PM
#6
Thread Starter
Lead Lap
Joined: Apr 2007
Posts: 522
Likes: 5
From: sc
I have a small update.. although I did not do anything and the problem has gone away... I swapped the right and left speaker input from the head unit and the problem swapped sides.. this points to the head unit. I took the head unit out, took the connector off and on off and on.. with static persisting. I turned the unit off via the button on accident.. and when i turned it back on. I could not make it get static. 
I cycled power several times with the key.. button.. I could not make it do. it.
So far so good.. I had it playing for an hour with the "bad" speaker blaring and no static..
We will see.. ..
BP
I cycled power several times with the key.. button.. I could not make it do. it. So far so good.. I had it playing for an hour with the "bad" speaker blaring and no static..
We will see.. ..
BP
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03-20-08 | 05:42 PM
#10
Thread Starter
Lead Lap
Joined: Apr 2007
Posts: 522
Likes: 5
From: sc
BP
03-20-08 | 05:47 PM
#11
03-21-08 | 06:45 PM
#12
Thread Starter
Lead Lap
Joined: Apr 2007
Posts: 522
Likes: 5
From: sc
I know we are having a conversation by ourselves over this topic..
I had my front drivers side door completely apart. PERIOD.
I had the housing separated by the 8 or 10 screws that hold it together.
The Diagram is right. There are not buried electronics hidden in the housing.
Take your door panel off and prove me wrong.
I will have mine off gain... the rears soon..(next two weeks) and I will take pics to prove that the diagram is right..
BTW..... I drove the car today......... We got in it everything worked good... got back in started it.. and the speaker messed up.. turn it off... back on and walalaaa.. it fixed it self.....
This is very strange to me..
BP
I had my front drivers side door completely apart. PERIOD.
I had the housing separated by the 8 or 10 screws that hold it together.
The Diagram is right. There are not buried electronics hidden in the housing.
Take your door panel off and prove me wrong.
I will have mine off gain... the rears soon..(next two weeks) and I will take pics to prove that the diagram is right..
BTW..... I drove the car today......... We got in it everything worked good... got back in started it.. and the speaker messed up.. turn it off... back on and walalaaa.. it fixed it self.....
This is very strange to me..
BP
03-22-08 | 02:13 AM
#13
yes but I know there are people out there with this problem...there are a few threads about this actually.
I was referring to "electronics" as in the el-cheapo crossover located inside the black housing. I was thinking maybe that's going out?
And any luck with finding an aftermarket amp? Someone suggested a simple way of ghetto rigging it...seems like a nice fix though.
Left front speaker failing - amp problem?
I was referring to "electronics" as in the el-cheapo crossover located inside the black housing. I was thinking maybe that's going out?
And any luck with finding an aftermarket amp? Someone suggested a simple way of ghetto rigging it...seems like a nice fix though.
Well its quite clear that its the low level output at the deck for that channel. There is a fairly inexpensive fix for this but you do have to sacrifice some of the capabilities of your Fading control.
If you can find a wiring diagram for this car then you are half way there. Find the two wires that are the low level outputs to the deck. If they are anything like the SC400, they share a common centre pin (or ground) with the rest of the outputs (left, right, front and rear). Once you find which one is left front positive, cut that wire. Locate the left rear positive and 'tap' (as in solder) on to that wire. This will give you good left channel information going to the rear and front left low level input of the amplifier. because its low level, impedence should not be an issue and the volume levels should be pretty much equal. You will not have proper fader control after you do this though.
If that doesn't work, I may suggest a new head unit install and do a complete amplifier bypass (run new wires to your speakers). I've done this many times - its pretty straight-forward. You just need a kit to fit the deck in the dash.
Good luck!
If you can find a wiring diagram for this car then you are half way there. Find the two wires that are the low level outputs to the deck. If they are anything like the SC400, they share a common centre pin (or ground) with the rest of the outputs (left, right, front and rear). Once you find which one is left front positive, cut that wire. Locate the left rear positive and 'tap' (as in solder) on to that wire. This will give you good left channel information going to the rear and front left low level input of the amplifier. because its low level, impedence should not be an issue and the volume levels should be pretty much equal. You will not have proper fader control after you do this though.
If that doesn't work, I may suggest a new head unit install and do a complete amplifier bypass (run new wires to your speakers). I've done this many times - its pretty straight-forward. You just need a kit to fit the deck in the dash.
Good luck!
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