Tiny Car Audio Amp.

**thwack** · 08-10-2006, 07:42 PM

Hi All,

i have been looking to replace my head unit with my car pc for a while, but I did not want to have a separate amp. After disassembling and old HU that I had lying around I think I may have a way to set everything up and still not run into space issues (everything must fit into a double din space)

I have found a schematic for an amp using the ST TDA738* range of car audio amplifiers. (I have a TDA7384 from an old phillips car stereo) this will put out 4x 25W of power to the speakers.

I am after comments and suggestion as to issues I may have. I will be powering this directly from a 12v battery source.

Thwack

**DJFriar** · 08-10-2006, 09:17 PM

It won't sound good, but it would work. But it won't sound any better than a standard car stereo.

Personally, I can think of no reason to not use an aftermarket amp other than cost, but if you are bilding a CarPC, then its pretty much a required component. I couldn't imagine spending that kind of money and pushing the sound through such a poor amp.

**thwack** · 08-16-2006, 01:27 AM

In my case the size of the amp is critical.
Yes a dedicated amplifier would sound better. But would also be much larger and require a second box and installation location. All up this amp is set to fill a size of 5.5 x 4 x 2.5cm. Not very large!!

It will give me 4x35W output. Try getting as much sound/size with any other amp.

This chip amp is the same amp as is used in many Philips car stereo's, so it can't sound any worse than a standard head unit would. If I wanted loud and obtrusive I would get a large amp .... But I don't.

I am mainly using my computer for navigation not audio. Though each has it's benefits. Lotsa mp3's when driving though the bush.

Thwack

**blkwrx** · 08-16-2006, 10:57 AM

I don't think he meant that it would sound bad because it wasn't loud. External amps do a lot more than just allow you to push the volume higher. HU also grossly over rate there power output so if it is a HU based amp I would guess you won't get more than 15w rms. This means your going to have to raise your gains to get to a good auditable volume (not loud just comfortable), pushing the amp and making it sound like crap. This is what happens in most standard setups which leads us back to DJFriar statement. If that doesn't matter to you then all the luck...

**JC-S60** · 08-16-2006, 11:18 AM

Sounds like an interesting undertaking.

You could also go with a velleman kit. They have small amps that run on 12v as far as I can remember.

http://www.velleman.be/ot/en/product/view/?id=9184 (but I don't know if it needs +12 and -12v)

Good luck!

**XC-C30** · 08-18-2006, 10:14 AM

Originally Posted by JC-S60

Sounds like an interesting undertaking.

You could also go with a velleman kit. They have small amps that run on 12v as far as I can remember.

http://www.velleman.be/ot/en/product/view/?id=9184 (but I don't know if it needs +12 and -12v)

Good luck!

Are the velleman kits that good for the purpous?

Maybe look into the amp-kits from 41hz.com? For what I've read about it, they should sound pretty desent.

edit: the specs on the velleman look pretty good, but then again, numbers don't say anything.