DAC vs onboard

ALTF420 · March 18, 2021

well I've got a X570 with Realtek ALC1220-VB onboard sound, but I bought a small DAC (with 96kHz 24bit 2 channel). However, if I look at the settings of my internal audio, it says it's got 32bit and 192kHz. I don't think I hear any difference (Tidal Master files on Sony MDR-7506 studio headphones).

Might my onboard sound actually be better than the dac? The dac has got a rather annoying noise, while the 3.5mm jack gets the coil whine of the GPU

WereCat · March 18, 2021

Good DAC should remove the noise. Since you get noise on both... you got 2 bad DACs.

rice guru · March 18, 2021

A dac us more than just how many bits it can output it's also about dac chip implementation and how good the amp is on the output stage every dac even stand alone ones have a amp to be able to output a signal if the implementation is bad or. Just the dac itself is bad you will hear noise. But a good dac should be absolutely silent.

Psittac · March 19, 2021

I have an at the time $500 dac/amp and have had my woes with PC noise. I don't know what DAC you have but it could be a crappy dac, it could also be a noisy PSU transmitting sound to your USB and your onboard audio is just shielded better.

I know that schiit at one point had a decrapifier that would remove usb noise but they discontinued it. I think it didn't sell well and higher end dacs are supposed to clean the usb signal? Maybe they just integrated the decrapifier into their units or maybe I'm just taking a shot in the dark. Maybe my dac/amp is just prone to USB noise.

At any rate I know for a fact that different PSU's make more or less USB noise within the same system. My end result was a pi2aes ($300 galvanic solution) but after a month or two of the new psu running it had little noise. It's only heard in tubes now.

H713 · March 19, 2021

As mentioned, it probably comes down to USB isolation. Good DACs do this well, and over the past few years they seem to have gotten considerably better. Modern Schiit DACs tend to be just fine with this. Some of their older products had much lousier USB interfaces- hence why they sold a "USB Decrapifier". If your DAC has a "rather annoying noise", then either the USB power and/or USB ground noise is absolutely extreme or it's a lousy unit.

I have never met someone who could tell the difference in a blind test between 96k and 192k sample rates. For one, almost none of the content you listen to will be available at those kinds of sample rates. Remember, CD quality is 16 bit 44.1 k.

Just because your onboard audio claims to do 32/192 does NOT mean that it actually does. In fact, I can promise you that it doesn't even come close to 24 bits of dynamic range, much less 32. They're simply regurgitating the specs of whatever DAC chip they used. 98% of the time, the chip is not the limiting factor, it's the implementation and supporting circuitry.

For better or for worse, the Sony MDR-7506 headphones are both very sensitive and rather bright, so they tend to make any noise issues obvious. They're also just about the single easiest load you could give a headphone amplifier, so you're unlikely to see too many differences in that department.