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Khadas or D30 (concerned with USB pc noise)

mt196

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#1
Hi guys, I just registered but I read a lot of threads here in the last weeks.

I have currently an AudioGD R2R-11 and I would like to swap it with Atom+DAC. I was really interested in the Khadas Tone Board + Case, but it seems that it measures worse with USB than Coax, or at least it can measure worse in case you have some noise coming from your USB. Since right now with the AudioGD I do hear a lot of noises coming from my PC USB when using my speakers, so when I am using the Preamp RCA on the back of the AGD (funny thing is that when using headphones I do not ear a single noise), I don't want to have the same/similar problem with the Khadas. Should I go with the Topping D30 instead and use it with SPDIF?

Marginal question: does the D30 have the same Hump than D50? I think not since they use different DAC chips, am I correct? I didn't find similar graph in the reviews to compare D30 with D50 and Khadas.

Thank you and I hope I didn't break any forum rule with this thread :oops:
 

Tircuit

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#2
Can't comment on the Khardas, but I'm using PC>USB>D30>Atom and I am very pleased. Easy setup, no noise.
 
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#3
well, the Khadas still measures better than D30 so i'll stick with it.
If you do not hear noises when you listen through headphones on your AGD using usb connection, maybe it's a problem of the line out section and not of the pc itself, for example it could be the amanero board irradiating EMI noise on nearby circuits (since the amanero is right next to the RCA outs), on this forum those products showed up a lot of engineering issues so i'll not bother with those problems so much, i think that another product from wesiontek or topping will solve it. You can still use an Y USB cable and power the khadas from a wall wart if you're still experiencing this.

The D30 should not have the hump in IMD distortion as D50, since it's typical of ESS chips and the D30 is using a CS4398.
 

WondrousHippo

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#4
Don't obsess too much about the numbers, you're talking about tiny differences at inaudible levels. So if the D30 seems better, go with that. Also it has a bit more input versatility.
 

GPJ

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#5
I use a D30 or Khadas on the same PC. Completely silent from both. I'd be hard pressed to tell them apart in a blind test with Aune X7S and HE-560 (balanced).

The same PC has an X-Fi Titanium HD......a very high spec'd card that is totally ruined by EMI. Fortunately these stereo outboard DAC's relegate internal sound cards to the dust bin. I will never use an internal card again. The modern day USB DAC destroys it.

I suppose there is a use for multichannel though....
 

atsession

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#6
I saw a recommendation on another forum for using a USB expansion PCIe card and decided to try that and it worked for me.
I used to use a Schiit Modi and it is very susceptible to USB noise and putting something like this: https://www.amazon.com/FebSmart-Sel...071P5C6CS/ref=cm_cr_arp_d_product_top?ie=UTF8
in my computer removed any popping or crackling from the USB port. I'm using a Khadas board now and it's working great using the same port from the expansion card. All the usb peripherals--like keyboard, mouse, thumb sticks etc. coming from the motherboard usb ports all probably contribute to the noise.
 
OP
M

mt196

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Thread Starter #7
well, the Khadas still measures better than D30 so i'll stick with it.
If you do not hear noises when you listen through headphones on your AGD using usb connection, maybe it's a problem of the line out section and not of the pc itself, for example it could be the amanero board irradiating EMI noise on nearby circuits (since the amanero is right next to the RCA outs), on this forum those products showed up a lot of engineering issues so i'll not bother with those problems so much, i think that another product from wesiontek or topping will solve it. You can still use an Y USB cable and power the khadas from a wall wart if you're still experiencing this.

The D30 should not have the hump in IMD distortion as D50, since it's typical of ESS chips and the D30 is using a CS4398.
The strange thing is that it doesn't happen with a different pc (a notebook) so maybe it is partially PC fault.

Since with the D30 I have more possibilities (coax, usb and optical) probably I'll go with that one, I was just curious to know why there are different graphs in that review compared to D50 and Khadas reviews.

A possible solution could actually be using a Y USB splitter, connecting Khadas to the PC taping the V+ pin on the usb and connecting the other end to a wall wart, in this way no electrical noise from PC should interfere
 
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