Hi all!
I want to buy a dac for a computer, many models were presented here [Advert removed] I settled on these two Topping D50s vs SMSL M500 If there is anyone using the same, I would be very glad of your feedback.Or you can offer some other models up to $ 500
Thanks!
I want to buy a dac for a computer,
Why? What are you looking for?
The DAC built into your soundcard is usually better than human hearing so if you want to spend $500 buy one with the features you like or one that’s sturdily built, or one that looks good etc.
The only sound quality issue from your soundcard might be noise, but if you’re hearing noise almost any USB soundcard, interface, or DAC should be OK. The other important specs (distortion and frequency response) will be better than human hearing unless something is seriously defective or broken.
Or, you can get a home theater receiver for less than $500 and it will support/decode surround sound from DVDs & Blu-Rays or it can create surround/spatial effects from stereo sources. Plus, it’s got an amplifier to drive speakers, a headphone output, multiple inputs, remote control and all that stuff. (You’d probably need HDMI instead of USB.)
If you want to improve your sound consider upgrading your speakers… Unlike DACs, every speaker sounds different. Or, you can get a pair of highly-regarded headphones in the $200 range. But, with headphones or speakers you should listen for yourself because the specs are often useless and opinions & preferences vary, and with headphones you need to check the comfort.
Or, just play-around with equalization! 
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Now… If you are recording you might need a USB audio interface, but not because of it’s ADC. The mic preamp built-into a soundcard is incorrect for stage-studio mics and it’s often noisy. And, most laptops don’t have line-inputs so if you are recording from a line-level device you may need an audio interface. The line-inputs on a regular soundcard in a desktop/tower are often adequate, again as long as you don’t you don’t have noise issues.