The problem is that by the time I get some built and ship them anywhere the price is 2-4 times what a completed amp is from China.
It is all about timing.
🙂
Yeah, DUG, what about that "extreme Avantgarde" PCB that you previously designed for the amp 😉.
Regards,
Same design, cleaned up a bit...no jumper on the bottom.
I am about to order a board from fusionPCB. (seeed) (non audio related)
And I have set up a paypal account.
I will look at their prices and see if it is better than I calculated before.
Still hard to compete with a complete amp for $17.
Dug,
If you can squeeze your board to less than 2x2 inches, I think Itead http://imall.iteadstudio.com/open-pcb/pcb-prototyping/im120418001.html will make qnty 10 for $10 shipping included. I hear it takes 3 weeks but results are decent. I for one am lucky enough to have your original board (thanks!) but would be interested in another bare board. 😀
Regards,
X
If you can squeeze your board to less than 2x2 inches, I think Itead http://imall.iteadstudio.com/open-pcb/pcb-prototyping/im120418001.html will make qnty 10 for $10 shipping included. I hear it takes 3 weeks but results are decent. I for one am lucky enough to have your original board (thanks!) but would be interested in another bare board. 😀
Regards,
X
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Well, I am not actually interested in the price, it's always been about the sound... If yours has a better designed board I prefer to spend a little more than just buy something for being cheap and then throw it away. I already had one of these DDX amps that just died sitting there, enough of half baked stuff for sometime.
What would you change about the board?
The schematic is right out of the data sheet.
The usual switch from ceramic SMT caps to poly caps, nicer inductors, bigger power caps is really all you can do. Has anyone tried setting it to 1.2MHz switching to see if the sound is better? My one experiment with switch from ceramic to poly caps did not result in anything discernable to my ears.
SMT caps to poly
I like my 10uF 0805 input caps
What does the graph on the poly caps look like? How big is a 10uF poly cap?
There are probably inductors that have better inductance vs current flatness but I would like to see the curves vs size compared to the ones I used.
There are things that I would change if I would like a larger board.
But
My criteria was power vs size.
IMHO I think it is not too bad.
If other people want to tinker with the components then they are certainly welcome to lay out a board themselves. Data sheet schematic...no magic hookups here.
The pin layout of this device is fantastic. No wires crossed, power on one side, signal on the other.
Love the sound the way it is...IMHO
🙂
Attachments
Dug,
I agree with you about the caps. The small size of your board is awesome - can it be at or under 2 x2 inches? Where do you have 10 uF input caps? I thought the spec was 1 uF? Or is that so that you can get ultimate low end bass extension? A 10 uF poly cap is huge.
I agree with you about the caps. The small size of your board is awesome - can it be at or under 2 x2 inches? Where do you have 10 uF input caps? I thought the spec was 1 uF? Or is that so that you can get ultimate low end bass extension? A 10 uF poly cap is huge.
digikey search...10uF
lots of them:
http://www.digikey.com/product-sear...=1&stock=1&quantity=0&ptm=0&fid=0&pageSize=25
Might be able to do 2 x 2.
Might try on the weekend.
lots of them:
http://www.digikey.com/product-sear...=1&stock=1&quantity=0&ptm=0&fid=0&pageSize=25
Might be able to do 2 x 2.
Might try on the weekend.
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Dug,
Good for you, rolling your own,
Sucks, that the Asian's can make something with TI parts, cheaper than I can by the parts from Mouser.
The Asian design looks to have some possible design/component choice issues, i.e. DC power, 2.1/2.5mm jack, is probably under rated. IIRC,, switchcraft seem to be the only ones making a high I silver plated, rest are tin, lower I. Inductors look to be under rated.
Know one seems to be making any measurements, only listening tests.
Suggest that you have a read of this app note from Maxim, lots of great ideas. Would like to put my tuner/media player in this unit.
Reference Design for a Class D, 2.1-Channel, Audio Amplifier for an MP3 Docking Station - Reference Schematic - Maxim
I checked the prices, maxim are much cheaper than the TI parts, but they do not have the same power as TPA3116 (50W).
Good for you, rolling your own,
Sucks, that the Asian's can make something with TI parts, cheaper than I can by the parts from Mouser.
The Asian design looks to have some possible design/component choice issues, i.e. DC power, 2.1/2.5mm jack, is probably under rated. IIRC,, switchcraft seem to be the only ones making a high I silver plated, rest are tin, lower I. Inductors look to be under rated.
Know one seems to be making any measurements, only listening tests.
Suggest that you have a read of this app note from Maxim, lots of great ideas. Would like to put my tuner/media player in this unit.
Reference Design for a Class D, 2.1-Channel, Audio Amplifier for an MP3 Docking Station - Reference Schematic - Maxim
I checked the prices, maxim are much cheaper than the TI parts, but they do not have the same power as TPA3116 (50W).
Input coupling, I use a 1uF/50V/X7R/1210. 1210 allows you to use 10uF. TPA Gain is set to minimum, so no need for a 10uF. Cap distortion will be much lower than the TPA, so it really will not matter, just extra cost/size. TI eval uses what? 0805/0603? = too cheap.