Hi there,

I'm in the process of building an eight-channel surround sound installation and for that obviously need 8 channels of amplification, with very high channel separation for maximum effect.

I'm looking for about 25W per channel. Could you suggest IC's I should look at? While I don't need Super-HiFi stuff, frequency response should be somewhat linear and predictable.

Oh, and the project is severely budgeted, since everything goes X8...

Thank you, any feedback is appreciated!

 

Take a look at Elliott Sound Products' website:
http://sound.westhost.com/projects.htm#index
Lots of amplifier projects that he's built and tested.

Since you specify 8x25W, just your power supply alone (> 200W) will be rather pricey.

 

MPJA.com currently has a deal on 24v 12.5a supplies.
http://www.mpja.com/prodinfo.asp?number=17429+PS
Two of those ($25/ea) for your +24/-24 rails would be a good match for this project:
http://sound.westhost.com/project72.htm

That'll give you just about 25w/channel. Build four of those amps, and you've got it.

 

Wow that was quick! Thank you, those few lines already help a lot. I'm studying those projects now.

Would you recommend the tripath ic's? Their efficiency looks like it might save me some money on the power supply, or do I get the wrong idea there?

 

Tripath IC's? I don't know what you're talking about.

The power supplies I suggested would be very good for your project. Linear supplies would be better from a noise standpoint, but would be cost prohibitive, power hungry, and would make good room heaters.

The amplifiers should be at least decent. The site owner wouldn't have posted them otherwise. The PCB's aren't exactly giveaways, but you'd spend about that much designing/ordering the boards yourself - and you'd skip all of the work (not to mention if you'd made goofs, and had to fix them.)

 

The Tripath site is down now or maybe they are out of business.
Their amp ICs use class-T which is something like class-D using something like high frequency PWM.

They lie about the output power. Their 15W IC has an output at clipping of 6 Watts into 8 ohms. It is 15 Whats into 4 ohms at a horribly clipped 10% distortion.

 

Tripath Technology, Inc. doesn't exist anymore.
They did a reverse merger earlier this year with Etelos Inc.
Tripath was basically bankrupt. They had huge internal problems with accounting and "cooking the books", and got the dickens sued out of them. They lost.

 

You guys are great - thanks for the wealth of information!

I'm going through the options now, the ESP boards look like a contender. Thanks again!