My 7498 Class D Amp

Hello.
This is my little integrated amplifier that I set up buying parts on Aliexpress.

TDA7498 from the black board.
SMPS 26V 8.5A (221W) power supply for use in industrial equipment.

Digital preamp with 3 line-in and 2 line-out, Bass, Treble and Loudness control and remote control.
Hot glue as a temporary feature to attach the display to the panel until I buy a tool to thread the front panel aluminum.

Speaker output terminal I left RCA until
Purchase the appropriate terminal for the speaker cords.
Hope you like it.

Ps: I bypassed the 2.2ohm resistors.

Ps: I don't know why some photos were inverted.
 

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A slight noise when no signal.
By injecting signal even at very low level the noise ends completely.
Probably your source - many digital players power down the output amp chip when idle, causing the impedance to rise to very high, generating noise. Its annoying (a good feature with earphones and when battery operated though)


You can cure this by adding a low value load resistor (few kOhms) on the input of the amp, on the assumption all the sources these days with be very low impedance. You could add such a resistor to a set of phono leads alternatively.


I've used some of these TDA7498 boards and they seem pretty good, though I'm sure there are some very cheap ones with inadequate filter components. The 2 ohm resistors are there for 4 ohm loads as the chip is rated down to 6 ohms. Its best to bypass the resistors and use only with 8 ohm speakers.
 
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Can I ask of the digital pre amp and display?

Great build. Well done. I use similar amp with 24v smps and an Ebay es9038q2m dac, Google chromecast, through Faital 3fe22. Sounds lovely . Overall cost well under 100gbp


This is the digital pre amp with display.
R$ 64,09 18%de desconto | Frete Grátis DC9-24V PT2313 Soundboard Digital Preamplifier Board (Conjunto Completo) Siemens Capacitores De Acoplamento de Áudio
AliExpress

I like him, but it's the simplest on Aliexpress. I must say there are some that should be better.
Beware of some that are with 5.1 input. It has neither bass nor treble adjustments. They are usually called PGA2311 / PGA2310.
 
Probably your source - many digital players power down the output amp chip when idle, causing the impedance to rise to very high, generating noise. Its annoying (a good feature with earphones and when battery operated though)


You can cure this by adding a low value load resistor (few kOhms) on the input of the amp, on the assumption all the sources these days with be very low impedance. You could add such a resistor to a set of phono leads alternatively.


I've used some of these TDA7498 boards and they seem pretty good, though I'm sure there are some very cheap ones with inadequate filter components. The 2 ohm resistors are there for 4 ohm loads as the chip is rated down to 6 ohms. Its best to bypass the resistors and use only with 8 ohm speakers.

Hello!

I'm really enjoying the amplifier and this noise has not bothered me yet. But I will do what you said.
About the 2.2ohm resistor, I jumpered under the board, I use 6ohms and 8ohms speakers.
 
Bump. I see the 7498 chinese thread is closed, I thought I'd ask a question here. I bought this amp awhile ago and never hooked it up. I played it and it worked at first and then I hooked it up again and no sound. Anyone know if it's fixable? The light still works, but no sound. Been over a year so can't send back. Here are some pics. Thanks for the help.
 

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We just have the same problem with what is believed to be a TDA7498E amplifier. I read somewhere that people have found TDA7498 chips in boards that should be TDA7498E.
What is your supply voltage?
It might be poor quality cooling-paste that migrates in-between the legs of the chip and causes interference. A problem with the TDA7498E chip (probably also TDA7498 chip) is that it is extremely small in size.
 
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Hi FF! Thanks for the reply. I'm using a 24 volt. I also have a 32 volt. Here is a closeup of it. I detached the heatsink so you can see. I don't own any patse and where to get it. I've seen some PC videos where they repast it. I sent the seller who is away till next week to see if he can help. So did you fix yours?
 

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