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A new Dac to improve sound quality from Khadas Tone Board 1

b4nt

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How many studio microphones used for recording instruments do you know reach 100kHz -3dB ?

That is not the point. 100k or 50k shall come with more linearity in low audible range (levels but also phase). Nagra is a well known professionnal grade and high range boutique, I assume they know what they do from microphones to line levels.

Can you record the same song (the part that sounds bad) from both DACs so the rest of us can analyze and listen for themselves ?

I can do this this week end maybe. That Ariana record is 44.1/16. I'll try to get 96/24 records from lines out of the three DACs.

Meanwhile, you may check the records I mentionned in #71.
 

solderdude

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That is not the point. 100k or 50k shall come with more linearity in low audible range (levels but also phase). Nagra is a well known professionnal grade and high range boutique, I assume they know what they do from microphones to line levels.

upper frequency extension has absolutely nothing to do with the lower end of the audible spectrum and certainly not in phase.
If anything the Nagra is 5Hz to 40 kHz (+0 – 3dB) so they have their post filter set much lower than the 100kHz of the RME.

Again, here too it does not matter because A: there aren't many recordings with meaningful 'info' beyond 40kHz and B: You can' t hear it anyway.
Absolute phase at higher frequencies with a slow phase change (post filtering) isn't of audible concern.
Only interchannel phase shifts (which would have to be substantial) could be audible.

The linked YT video: I can' t hear nor see anything ' unexpected' at 0:47

analysis.png


Of course it is YT, BW limited, severe loudness compression and clipping. I would not use this track for anything else than just listening to it.

clipping.png
 
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b4nt

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If anything the Nagra is 5Hz to 40 kHz (+0 – 3dB) so they have their post filter set much lower than the 100kHz of the RME.

Nagra could have their post filter at 100k and their lines outputs at 50k only. Those a disctint things.

According to their specs, RME shall have lines out at approx 100k (whatever filter is).

If I well remember, in the earlier post you mentionned, from 20-20k(-0,1), one assumed Topping D50s has his lines out at 80k or so.
 

b4nt

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The linked YT video: I can' t hear nor see anything ' unexpected' at 0:47

That is in the FLAC file, for YT video. On YT, you shall notice it, but weaker (due to compression there).

I think it is that plop I mainly hear from FLAC, then, another at least follows:

ToppingTheMarias.PNG
 

b4nt

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I recently had big EMI and noises issues. Found also my RCA cable was occasionnaly catching 4G RF harmonics. I solved all this on my hardware.

By the way, I could dinstinguish this in Arpo, Call Super, record, seems to be low level 4G harmonics noise inside the track:
ToppingArpoCallSuper.PNG
 

solderdude

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Why would that be 4G and harmonics at that ?
It must be below 20kHz.
You can select that small area and do a spectrum analysis.
 

solderdude

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According to their specs, RME shall have lines out at approx 100k (whatever filter is).

One day you will have to enlighten me what you mean by that.
The output circuits, most likely, are just the outputs of the post filter opamp with a 100 ohm in series.

Nagra obviously thought 40kHz (not 50kHz) was enough and did not want to set the filter at 80 to 100kHz or so.
It's a design decision and not an audible one at that.
 

b4nt

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Why would that be 4G and harmonics at that ?
It must be below 20kHz.
You can select that small area and do a spectrum analysis.

Any cables or electronic magic.

I found out my own 4G phone was producing exact the same low level interferences and noises. Since, I changed my RCA cable for a better shielded one. But I still got some if my phone is too close (20cm or so) from my Topping DAC and RCA cables (which are on my desk). Now when I still hear such noises, I just move my phone away.

Watch that video (it covers 2G, 3G and 4G), then test yourself using your 4G phone, scroll with a app like Twitter for constant 4G activity:

 

solderdude

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There really is NOTHING strange about interference (not harmonics) of a phone signal. This is caused by the high power 120Hz pulsed RF when connecting to towers (broadcasting at full power before deciding which tower and power level is needed) and are the, familiar to most, weird tones.
The RF energy at a few cm away from the cable is often unavoidable and is allowed up to a certain distance.
Yes, some interlinks screen worse than others. Nothing weird about that.

What's it have to do with the level difference of the OP's 2 DACs ?
What's it have to do with bandwidths, post filters ?
 

b4nt

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One day you will have to enlighten me what you mean by that.
The output circuits, most likely, are just the outputs of the post filter opamp with a 100 ohm in series.

That picture is from AD (maybe from outdated topologies... the Fiio has such, the Aune should have such). I'm basically refereing to the split one can make between between DAC functional bloc and lines buffers functionnal block:
 

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solderdude

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functional blocks say little to nothing about actual circuits, actual PCB layout, power supplies, ground decoupling, etc.
Why bring something up that, again, as zilch to do with the OP ?
Why bring up an old config from an R2R DAC that is not used in any of your DACs ?
 

b4nt

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What's it have to do with the level difference of the OP's 2 DACs ?
What's it have to do with bandwidths, post filters ?

This was just to inform you i'm able to distinguish noises produced with my setup or environment, whatever sources or causes are, from noises inside tracks. so later, I'll provide try to provide you a record from my Fiio.

Meanwhile, listen to Hush and to Arpo, try to hear that noises. If you don't hear them, you won't hear what the Fiio adds (but we shall see differences in the records).
 

solderdude

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The FiiO X5 adds nothing. It just converts digital sample values and calculated intersample values and then converts that to about 4 bit deep ' average values' (average over time to the belonging sample values) that get further averaged by the post filter (that's what it is for) by removing the HF crap.

My FiiO certainly does not add or change anything and under equal conditions is indistinguishable (with the proper filter settings) from any other DAC I have.

The fact that you can distinguish can be caused by the file, by file handling (EQ applied), filter used or anything else in the chain or the used files.
We don't and can't know what you perceive and why.
 

b4nt

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functional blocks say little to nothing about actual circuits, actual PCB layout, power supplies, ground decoupling, etc.
Why bring something up that, again, as zilch to do with the OP ?
Why bring up an old config from an R2R DAC that is not used in any of your DACs ?

That is in the output stage of the Topping D50s. Is this part of the filter or is this a basic lines buffer?

It seems forseen to allow some one to change the op-amp... to tweak the sound characteristics:
14030-topping-d50s-inpage6.jpg
 

b4nt

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My FiiO certainly does not add or change anything and under equal conditions is indistinguishable (with the proper filter settings) from any other DAC I have.

Filter at your convenience. And listen better to Hush and Arpo.
 

solderdude

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Correction... it is 'swapable' because people believe that this imparts a sound signature and those that do believe will prefer a DAC that offers this.
 

b4nt

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Correction... it is 'swapable' because people believe that this imparts a sound signature and those that do believe will prefer a DAC that offers this.

This is just a wording correction. Take two DACs from different vendors, and with the same digital to analog chipsets. If those vendors do not use the same op-amp at the output stage, their sound "signature" will be different.

Sorry. You say all DACs sound exactly the same.
 

solderdude

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