Newb with stereo questions.

[kjvbluexj]

I just bought a 98 XLS and the head unit was not working at all. So I had Fry's install a new HU and they informed me that the factory amp is on its way out. The sound quality is just fine, but there is a faint high-pitched whine that goes up and down with the engine speed. They're suggestion was to bypass the amp and run the speakers directly from the head unit. I asked about the possibility of replacing the factory amp and they said that should work just fine. So here are my questions.

1. How do I know whether I have the 6 speaker or 7 speaker setup? The Toyota dealership tells me it's a different amp for each system.

2. What are the chances of me finding a replacement factory amp(new or used) for less than the $700 - $900 that the dealer wants for one?

If I can't get it for less than $50, I'm probably just going to have them bypass the amp. I imagine there has to be a factory amp sitting inside some Avalons in wrecking yards, or from people install entirely new systems...

[kjvbluexj]

Or am I just better off bypassing the amp and not even worrying about replacing it? How will the sound quality be affected?

I have this head unit installed.

http://www.crutchfield.com/p_020CX40...ch=cx400&ssi=0

[kjvbluexj]

Nothing? No One?

[Chunkywolf]

If your system is the 7 speaker system, the subwoofer won't work if you just hook up the speakers directly to the head unit, BUT also, if you get the wrong amp(OEM), it may not support the subwoofer. I haven't looked much into the OEM equipment I have, since it's not that impressive, but it is definitely worth looking into in your case. considering you could lose a lot of sound depth by losing the subwoofer.

[jbfrench]

If you have a speaker mounted in the molding of the center rear brake light then you have the 7 speaker system.

If you can't find an oem amp, don't worry, just buy a 5 channel amp. These 5 channel amps can actually improve your sound quality because like ChunkyWolf said, the oem amps aren't very impressive. These amps have 4 channels for the cabin (front right, front left, back right, back left) and one for the subwoofer. This covers all 7 of your speakers, since the back doors have 2 speakers a piece. These can be had off ebay for less than 200 bucks or Crutchfield for 350 or more. But 500 dollars for a Boston Acoustics amp (great brand) is less than the oem and will probably yield better quality and more options.

http://www.crutchfield.com/g_347150/....html?tp=35808

But your head unit does have a 4 channel amp built in, which might be enough to power all 7 of your speakers. The 7th speaker (the subwoofer) might just be wired into all 4 channels which means you don't even need an oem replacement amp. The head unit will probably provide better sound than the oem amp.