Tda8924

[bostjancek]

Hello!

I've got some of the Philips TDA8924 - 2x120W class D power amps. I'm asking if it is worth to build something with them? Is the schematic on the datasheet optimal or I must go on the different way?

If someone used this chip - wat is the sound quality of the given amp?

Cheers

 

[Spasticteapot]

I'm bumping this. I need a subwoofer amplifier!

 

[Neil Davis]

An externally hosted image should be here but it was not working when we last tested it.

I used a modified version of the layout in the 8920 datasheet, and the amp seems to work fine. I haven't really done much with it yet, but it runs cool and seems to be a good amp.

I had trouble with the inductor getting hot using a 7A JW Miller 2100 series device, but switching to a 2200 series low-loss coil did the trick.

 

[Spasticteapot]

An externally hosted image should be here but it was not working when we last tested it.

I used a modified version of the layout in the 8920 datasheet, and the amp seems to work fine. I haven't really done much with it yet, but it runs cool and seems to be a good amp.

I had trouble with the inductor getting hot using a 7A JW Miller 2100 series device, but switching to a 2200 series low-loss coil did the trick.

I'm pretty new to DIY anything. Expect dumb questions to ensue.

I presume that the Miller object you refer to is the output inductor?

Also, do you think this would be a reasonably easy 1st Class-D project for someone with decent soldering ability (providing he's not using his craptastical soldering iron with corroded tip)?

I'd need some practice with SMD work, but it's hard to argue with the output power!

 

[Neil Davis]

Also, do you think this would be a reasonably easy 1st Class-D project for someone with decent soldering ability (providing he's not using his craptastical soldering iron with corroded tip)?

I'd need some practice with SMD work, but it's hard to argue with the output power!

There are a couple of traces that go between SMD component pads, so you need to have good SMD soldering skills and the right equipment. However, there is nothing smaller than 0805 SMD chips, so it is possible to hand solder if you have a temperature-controlled iron with a fine tip. I wouldn't characterize this as an easy project, but it was easier to do than I expected.

 

[Spasticteapot]

There are a couple of traces that go between SMD component pads, so you need to have good SMD soldering skills and the right equipment. However, there is nothing smaller than 0805 SMD chips, so it is possible to hand solder if you have a temperature-controlled iron with a fine tip. I wouldn't characterize this as an easy project, but it was easier to do than I expected.

I'll try something else, then.
Can you reccomend an alternative for a subwoofer amplifier? The quality need not be astounding - distortion is usually lower at low frequencies, anyway.

 

[Neil Davis]

Can you reccomend an alternative for a subwoofer amplifier?

I have no idea what your objectives are and what constraints you have, so I can't make a recommendation. However, I can point out that due to the high manufacturing volume, the subwoofer plate amps available at MCM, PE, Apexjr, etc are hard to beat--there is no way the DIY'er can build something comparable at the same price. Take a look at my plate amp modification page. There's no Class D stuff there, but there are some ideas that you may be able to use.
Plate amp modification page

My page for DIY plate amps is at: DIY plate amps

In the next update cycle I will add the TDA8920 amp details. But that won't be until I have put it through some testing, and I don't know when that will happen.

 

[Spasticteapot]

I have no idea what your objectives are and what constraints you have, so I can't make a recommendation. However, I can point out that due to the high manufacturing volume, the subwoofer plate amps available at MCM, PE, Apexjr, etc are hard to beat--there is no way the DIY'er can build something comparable at the same price. Take a look at my plate amp modification page. There's no Class D stuff there, but there are some ideas that you may be able to use.
Plate amp modification page

My page for DIY plate amps is at: DIY plate amps

In the next update cycle I will add the TDA8920 amp details. But that won't be until I have put it through some testing, and I don't know when that will happen.

I have a bunch of transformers, capacitors, and whatnot handy. Also, I'm building an active filter for my Gainclone, so adding a mixer and low-pass filter would not be too hard.

The plate-amps are nifty, but I am what you would term a "horrible cheap-***", and don't feel like paying 50$ for a cheapie amp.

 

[sulc]

Anyone know which Epcos core is usable for coil ?

 

[Bender.ru]

http://www.diyaudio.com/forums/showthread.php?s=&threadid=109430