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Class D Switching Power Amplifiers and Power D/A conversion

Fasten seat belts.  TDA8932 pessimistic review.
Fasten seat belts.  TDA8932 pessimistic review.
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Old 26th January 2016, 01:05 AM   #111
abraxalito is offline abraxalito  United Kingdom
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Perhaps a different page or offering from the one I received. Definitely the RF board is inside (a small daughter board fitted perpendicularly to the 'top shelf' PCB), with attached antenna cable, in mine.
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Old 26th January 2016, 01:28 PM   #112
Lo_Tse is offline Lo_Tse  Canada
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Quote:
Originally Posted by abraxalito View Post
Perhaps a different page or offering from the one I received. Definitely the RF board is inside (a small daughter board fitted perpendicularly to the 'top shelf' PCB), with attached antenna cable, in mine.
Hmm, interesting. I opened the webpage that was described in your post and that's what I read. However, on the same page, photos of whatever you described (daughter board attached to the antenna) was also shown?? Anyway, good to know that the amp worked fine.
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Old 28th January 2016, 12:35 AM   #113
orto is offline orto  United States
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Got my Sanwu blue board setup for testing in a portable bluetooth speaker today. Feels like it's not going to cut it at 12v. I'm using it to drive a single Aura NS3 8ohm speaker and something just doesn't sound right. Comparing it to a few of my TDA7297 modules is night and day, the 7297 is ahead. I've got a non bridged 8932 module as well, so I'll test that out and report back.

I think I remember somebody saying it might not be a good idea to undervolt this amp, and so far I'd have to agree with that.
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Old 28th January 2016, 04:00 AM   #114
danielwritesbac is offline danielwritesbac  United States
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Quote:
Originally Posted by abraxalito View Post
I've never heard of GigaWave, certainly that would be a very good explanation for why my phone didn't find it. I'm not so interested in that part of the EOS box so not going to swap over to Bluetooth just yet.
But I really love that PT810.
Cost like a sandwich. Has CD specs. Works better than a CD player despite MP3's. Specs says 30ft. Actually works to 20ft with an android or 14ft with an iPhone. Fantastic. Also, a whole lot more relevant than that GigaWave errata.
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Old 28th January 2016, 05:41 AM   #115
danielwritesbac is offline danielwritesbac  United States
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Default Big Bro, just so you don't get bored. . .

Class-D|NXP <--Link
The TDA8920, TDA8950, TDA8954 have developed boards available.
Of these, the TDA8950, this one: TDA8950 120W 120W Class D Amplifier Board L | eBay #301442111174
This!
1). It can recycle that transformer you bought for a gainclone. Way back in the day, I bought one with right voltage, insufficient amperage. Oh yeah! Fair game. An efficient amp can make use of that, hypothetically (there's not proof yet).
2). See picture in ebay link and you'll see why I bought it. Not only is it factory standard in SE mode (they all share the same gain fault so that SE mode has higher fidelity), but also, none of the developed boards have high quality array decoupling like is available for TDA8932. In the picture, you can clearly see that the overlarge two-big caps bad quality decoupling, lousy bridge rectifier and outright dangerous screw terminals can be cleaned right off the otherwise nice board, resulting in a straightforward blank space available to install something better, very easily.

I bought it immediately!
One means to work wouldn't be enough to buy the thing, but two means to work, was apparently fascinating enough to make a purchase.

TDA8950 has as much effective audio power as two of LM4780 run parallel, possibly. But it certainly doesn't have more than that, as the datasheet suggests, wrongly. So, from my one board, I expect up to 67 watts per channel to 8 ohm loads or almost twice that to 4 ohm loads. I won't get that much with my transformer; however, efficiency, only if factual, might make that transformer useful.

In comparison with my TDA7293's, of which a stereo pair (to my schematics) will waste only 17W more into the the heatsink than TDA8950, I cannot predict how such a comparison will go. For sure, I will remove the cheapskate power circuit from the TDA8950 board and replace it with something more practically beneficent, because I have done the same for my TDA7293's and that did raise my expectations a bit. I don't know if the TDA8950 will want parallel 100u, 220u, 330u, 470u, nor how many of those it may want paralleled, but I will identify that and provide it before making any comparisons. With some practice, the matter is simple; however, there is a spot of labor for it. Indeed it would be unfair to do it for one amp and not the other.

This will not be perfect. The only solid data so far is that I thought the layout favorable for modifications and thought it worth the $19 because finding out what happens might be meritorious in some way yet to be identified.

Indeed, I really did buy the TDA8950 amplifier board because the worst thing about it can be removed and replaced very easily.
I don't know if that will be enough for validity.

I didn't buy the TDA8950 board because the TDA8932 board failed to do something I liked, but rather because the latter made me get curious. The TDA8932 in SE mode did successfully fill the need for my office. They're really valid for production efforts, but although practical tone is easy with these, the Hi-Fi thing isn't easily done because SE mode reduces output power, so they're just interesting enough to find out what "Big Bro" can do.
I was curious enough that the expenditure of $19 seemed fair.

My intended mods also cost a separate power supply board. And, mine are bulky. Just sayin.

Will there be a bit more of pretty sounding audio? I don't know yet.
Awaiting the postman.
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Old 28th January 2016, 07:18 AM   #116
abraxalito is offline abraxalito  United Kingdom
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Quote:
Originally Posted by danielwritesbac View Post
They're really valid for production efforts, but although practical tone is easy with these, the Hi-Fi thing isn't easily done because SE mode reduces output power, so they're just interesting enough to find out what "Big Bro" can do.
I have my active set-up running now and can confirm that in BTL mode with a 2.5:1 step down trafo, into a 4ohm bass/mid they're the highest fi chipamps I've had in my system. Tweeters are being handled by one of the cheapest chipamps out there, a TDA1521A again with an output transformer (its a bit current-limited but swings a wide range of volts).
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Old 28th January 2016, 02:42 PM   #117
doctormord is offline doctormord  Germany
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Quote:
Originally Posted by danielwritesbac View Post
But I really love that PT810.
Cost like a sandwich. Has CD specs. Works better than a CD player despite MP3's.
Yeah, sure! A2DP V1.2 == SBC
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Old 28th January 2016, 05:13 PM   #118
Buehgemeiste is offline Buehgemeiste
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Quote:
Originally Posted by danielwritesbac View Post
The TDA8920, TDA8950, TDA8954 have developed boards available.
Of these, the TDA8950, this one: [url=http://www.ebay.com/itm/301442111174?]TDA8950 120W 120W Class
I have an eye on that board, too.
The price is just right.
There ist another interesting 8950 board:
http://de.aliexpress.com/item/12-14V...7-7eb7cecbdfac
It looks like it is made for the use with a single 12V battery.
Did i get it right that this board has an voltage converter for 12V single rail to dual voltage like 24V-0V-24V onboard?
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Old 28th January 2016, 07:57 PM   #119
doctormord is offline doctormord  Germany
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Yes
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Old 30th January 2016, 07:38 AM   #120
danielwritesbac is offline danielwritesbac  United States
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Quote:
Originally Posted by doctormord View Post
Yeah, sure! A2DP V1.2 == SBC
For the PT810, means to work also include decent range, absence of ground loops, and its own private power supply. So, the analog portion of means to work have the basic necessities of a high end source. Sure, the digital specs are outdated; however, it does still have practical means to beat most sound cards by a comfortable margin, for the price of a sandwich. As the topic involved using a phone for the source, I think the PT810 a valid part.
See also the Hiby app.

For the sake of clarity, please ridicule/lambast proportionately to error. The horn haplessly stuck nonstop on the car isn't nearly as helpful as a little blast when the stoplight went green. Please review that difference in effectiveness. Also the option of making better quality helpful suggestions is something you might like to try out, for the novelty of it.

I think that your input and contribution could be fantastic, but please make the amplitude considerably more dynamic!!! Either silent or nonstop blast is same as mute, except that one option is slightly more annoying. But, I don't want you to be muted in either way.
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