Bypass amplifier?

I'm trying to install an aftermarket Sony CD receiver in my '05 Sonata.
There's power to the unit but no sound. Is there an amplifier on this
car I need to bypass? If so, how?

 

wrote in @g43g2000cwa.googlegroups.com:

Do you have the receiver hooked up with a hyundai wiring harness?

 

Yes, I plugged in the existing harness to the Hyundai harness that
Crutchfield supplied with the new head unit. I've read about bypassing
the outboard amplifier but can't find any info on how to do it.

There's power and a signal (can see the graphic eq on the unit moving)
but no sound.

 

wrote in @g44g2000cwa.googlegroups.com:

Does the unit have an "aux" (or some other named) button that you
accidentally pressed? Is your fader set incorrectly (feeding signals to
non-existant speakers?) Wish I could help more but I'm one of those that
needs to see something in person in order to fix it. That's why I'll never
work a help-desk.

 

Can someone help with the amplifier question? Someone must have had
this same experience.

 

I think you're on the right track, but I unfortunately don't have the
answer; I'm not that knowledgeable about audio components.

I think Richard Steinfeld may have some expertise in this area. Perhaps
if he sees this he'll have something to offer.

 

I did.

Note that my audio knowledge is in home and professional recording and
broadcast systems. Car audio is quite specialized and has an almost
unique ability to permanently shred the driver's hearing apparatus and
create real drive-by misery to others. Having gotten this off my chest,
I'll attempt an answser.

From what you've written, I think that the place to zero in would be on
what's sometimes called the "processor loops." In other words, there may
be a signal out point and a mating signal in point. We're talking about
four jacks here.

Some car stereos have this ability -- the idea is to be able to run the
audio from the head section (tuner, CD, etc.) out to an external
processor device (originally, an outboard equalizer). The signal is then
returned into the unit after processing to be fed into the stereo's
power amplifier stages; from there, the amplified signals go out to the
speakers. You may wonder why there could be connections for your unit
since it's already got an equalizer. Well, some people might get talked
into using an echo device -- which nobody ever needs because all
recordings have exactly the desired amount of echo already and adding
more is like (them metaphor in my mind is not suitable for children).

Two methods of switching are used for such a "loop." One is to use one
jumper cable permanently attached between the jacks for each channel.
The other is via a digital switch in the receiver. Since it's 2005, I
suggest reading the instructions carefully to see if you've just gotten
a menu selection mis-set. And, yeah: some of Sony's instructions can be
the worst Japlish ever conceived -- complete with insane names for
functions and explanations that never made sense in the original
Japanese in the first place (My Sony digital camera has a "sports
lesson" mode!!).

Another possible point of signal interception may be in order to
accomodate external crossover networks, "subwoofer" amplifiers, etc., etc.

So, I recommend putting this thing on your workbench, connecting it to a
12v battery and a pair of speakers, and while reading the manual, try
slogging through the menus. I think that this is going to work. You
should have an antenna to test the FM (a short wire will do if you're in
an urban area)and a CD for raw sound. The reason for doing this out of
the car is to see if the unit is, indeed, working OK.

I'm guessing about your unit totally, so I really don't know what you've
got. But if you get sound on your workbench, this eliminates the stereo
itself as the source of the problem.

For speakers on the workbench, you can use just about any speaker ever
made. Home speakers are fine. You'll just get less sound from them. You
won't damage the car stereo using them. However, whatever you do, do not
short circuit the speaker wires together -- even one strand of the wire
touching the other polarity can instantly fry your output ICs.

Always keep in mind that in a car, an honest 5 watts is a hell of a lot
of power! 15 watts will be across the threshold of pain. And it doesn't
make sense to spend lots of bucks on car stereo because you can't hear
the quality over the road noise. In other words, I believe in keeping
car sound systems really simple and save the money for the good stuff at
home.

Another option that occurred to me is that your stereo may just be
what's called a "head" unit -- in other words, the equivalent of what in
high-end home audio has been referred to as a "tuner-preamp." In this
case, there's no speaker power at all -- your unit is intended to work
into a separate amplifier in order to drive the speakers. Hmmm. You did
use the phrase "head unit," didn't you? If so, you _must_ use this with
an external amplifier. A low-powered one should do nicely.

Further, I really doubt that Hyundai put a separate head unit and power
amp in any car. Why bother? It's not needed in any car. So, I'll assume
that the original factory stereo was the traditional all-in-one box with
speaker lines coming out. In other words, there's never been an OE amp
in your car to bypass. Perhaps I'm wrong and somebody else can correct
me here. But if I were Hyundai, I sure wouldn't waste money on this
extravagance.

Finally, if you're not sure about what you're doing, you may want to
hire an installer to get everything right. As I said above, car audio
has always been somewhat specialized. I was just inside an old Motorola
AM-FM car radio that my friend bought on eBay for his 70s Mopar muscle
car -- he paid big bucks for the thing. I did some preventive servicing
on it for him, and I had to marvel at the uniqueness of what I found
inside it, and also the excellent reception and decent sound, still
after all these years. Impressive.

Richard

 

from what i heard thre is an amp in sonatas in the trunk behind the
liner unplug it then run wires straight from your stereo or re- route
then.....

 

I can't talk about the particular year, but I have the highest-cost 2000
Sonata and I can assure you that there is no separate amplifier in it.

Richard

 

I also wonder about this. I hooked up my kenwood head unit in my 04
Sonata and I get power and no sound. Can anyone confirm for sure that
there is some kind of external device. Also, do you need to use the
"Power control wire" from your head unit? Any help at all would be
appreciated.

 

After much headache and sweat, there IS an amplifier on the 05' Sonata. It is in the trunk under the trunk panels secured by plastic pins. It's on the passenger side bolted to the frame with three screws and nuts size 10mm. It is hooked to the cars wiring harness for the OEM stereo. It has a 25 amp fuse which I found out doesn't have to be bad for the amplifier to be fried. If the amp is blown, You must un-hook the harness to the amp before hooking up a new head unit/receiver OR you WILL blow up the new unit! Trust me I know! I have went to numerous professionals and the best advice is to by-pass the amp, re-string wire and go direct to new unit and speakers. I've also heard a person should find where the amplifier harness goes into the engine compartment and unhook that end as well. Not sure if I have the hoospa to do that. I'm so totally bummed, it's so much work to just get some tunes!