Ebay cheap TDA7498 boards

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Hi all,

I'm building a hi-fi for my wife for christmas and just bought one of these TDA7498 boards to do the heavy lifting of driving the speakers:

TDA7498 100W 100W Class D High Power Amplifier Board DC20V to DC36V | eBay

There seem to be tons like them on eBay.

Anyone had any experience with them? Any modifications that have to be made to make them sound good? They look fairly decent, with WIMA type caps on the output filter and a decent heatsink...
 
I've just finished an amp with this board 100W TDA7498 100W High Power Digital Amplifier Board Amp Board with Radiator | eBay This board has way larger/better chokes which makes a big difference when played loud/hard. I would only recommend this board with 32V to 36V which gives you more power than a tpa3116 which has the potential to sound a bit more detailed. Tpa3116 has 400khz switching frekvency and the TDA7498 has under 200kHz which is a bit too low and gives white noise faster when pushed to the limit. But when driven at 36V the limit is way higher than on the tpa3116(maks25V) so its a lot more powerful when driven at 36V:)
The sound from the linked card is some of the best I've heard from any stock board mention earlier. No sibiliance and no harsh treble, but with a lot of punch in the bass! I highly recommend it!
Ofcourse you could swap out the ceramic smds with film smds which would probably make it more detailed. I also swapped out the powersupply cap to a better aluminium electrolytic for more current control. That cap was the only mod I did and I didn't listen to the board on beforehand. The chokes on this board bought seperately cost more than the entire board linked so I think its a great buy!
 
i own that board from the original post.
you can find it cheaper on ebay (it was like 11€ shipped to germany).
i had ordered the board from the second post, too.
but it never arrived and the seller is an a**hole.

yes, the output filter of the black board is really weird.
it actually is only "one half" per channel.
(i will look that up when i´m home and post the values; they also differ from the datasheet-circuit.)

BUT:
the amp sounds really good for its price.
the cheapest tpa3116 (red yuan-jing board and unmodded black yuan-jing) sounds definitely worse.
but a modded tpa3116 or a better board like that from sure-electronics might be better.
the tda7498 plays lower on the same fullrange speakers and the high mids are not that harsh.
there are not many options in that price range and the for 11€ that black 7498 is not the worst.
one thing to consider might be that the datasheet doesn´t suggest 4 ohm speakers.
some sellers say it would be possible to drive 4 ohmers with tda7498, but i didn´t try it yet.
another reason to consider the tda7498 might be that there seems to be no higher spl into 8 ohm speakers from single dc supply available.
 
I will use a metall case and I will use short cables to my subwoofer, because the cables and the speaker influence the characteristics of the class d amplifier (by the way I bought the US $12.86 tda7498 from aliexpress, tzt trading including free transport to Switzerland). I read that class d especially tripath cause high frequency emi, hopefully I needn't add an elektor HF Filter.
 
I do not hear any interferences between those boards and my pc although they sometimes are without an enclosure next to each other on my desk.
but you have to take all my statements with the grain of salt, because i have neither highest claims in sq nor do i hear everything that other guys describe when they talk about their amps and speakers and preamps and cables and so on.
 
Hi Buehgemeiste
Have you used a plastic enclosure?
How did you connect the 3 pin connector for the input? On ebay ther are special cables "2.0CH Audio Input Connector Cable" (i have bidden, but I don't want to pay EUR 5 for that cable, it's not even shielded). I have ordered the tda7498 today and I'm awaiting the delivery (I'm also waiting for the tda7297 board, which was € 3,23). Has anybody used the tda7498 with 12V? According to the data sheet, it would work and deliver about 12W, which would be sufficient to me with minimum distortions. I wonder weather or not the cooler is sufficient for 100W (passiv).
 
omg, i´m really a noob, so i hope some of the more experienced guys will support us.

yes, i have tried both plastic and metal enclosures.
both work well for me.

the 3 pin connector is a special type of jst-connector.
jst + two letters, but i do not remind which atm.
for testing and fast switching between hardware i use dupont wire.
you can remove the connector carefully and wire the rca-connectors (or whatever you use) directly to the board.
inside one enclosure i gave to a friend i used a crimped connector like this one Housing Connector 2.54mm 3 Pins
but i had to cut away some of the plastic surrounding the pins on the amp, so the connector fits in.
if you are willing to modify the plastic you can use pretty much any connector for 2.54mm pitch.
 
I will use a metall case and I will use short cables to my subwoofer, because the cables and the speaker influence the characteristics of the class d amplifier (by the way I bought the US $12.86 tda7498 from aliexpress, tzt trading including free transport to Switzerland). I read that class d especially tripath cause high frequency emi, hopefully I needn't add an elektor HF Filter.
I have one of these on the way too (paid $12.67 during the 11.11 sale on Aliexpress) along with this PSU which I got for $18.65 including shipping. Will be fun to see what such cheap parts can do with my Q Acoustics 2050i speakers. :)
Btw. the impedance of the speakers is rated 6Ω nominal (4Ω minimum). Does that call for any mods?
 
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i disassembled the heatsink and one of the big white 5W resistors to see all the traces.
this is actually even more weird than i tought.
i used ltspice to draw a circuit diagram of the output filters i have on my board.
i'm waiting for this board to arrive:
Assembled TDA7498 (100W+100W) class A Power amplifier board-in Amplifier from Electronics on Aliexpress.com | Alibaba Group
i bought it on the 11.11.-sale.
it seems to use a lot of through hole components.
so my goal is to mod that with trevmar's suggestions from this thread:
http://www.diyaudio.com/forums/clas...tput-filter-designs-sure-tda7498-example.html
and compare it to the black board.

edit:
R1 and C1 are smd parts beneath the heatsink (long traces between the chip and the L's).
The 220n (blue) are 22K63 and look very cheap.
The 33n seems to be a film resistor.
R2 is a 5W rated cement resistor.
 
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Received the board tonight, so naturally I had to test it straight away :p

Pleasantly surprised. I'm not 100% on the sound yet (only tested it via Youtube on PC, need to find a CD player) but it sounds alright, with plenty of punch.

Building a case to put it in soon.
 
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