[DjBobby]

Instead of the hub, wouldn't that be a question of cutting the +5V wire on the usb cable?

Well I guess it leads to the same improvement.

 

[bogi]

It would have sense to cut the +5V VBUS wire at the USB B type connector, so the high frequency noise from it would not influence data wires along the cable. When external power is not needed, such solution is better than substituting one power source with other.

USB B type adapter on this product strips +5V wire on the female side of the adaptor:

Just plug your current USB cable into the female side of the USB B type adaptor.
The USB type A branch of this product is intended to be used to inject clean power, but with D50 is not needed, since D50 does not require external power. You can simply let it unused.
https://www.audiophonics.fr/en/vari...e-for-external-usb-a-power-supply-p-8389.html

 

[spacequeen7]

Wondering why would the USB input sound so much worse than the spdif and why would connecting an external usb to spdif converter like SMSL x-usb II bring so much improvement while using the very same xmos as already built in the D50, I think I came to the solution. For some reason with the devices I was using until now, i never had any bad experience with the noise and distortion issues connecting usb dacs, probably because they were galvanically isolated or properly filtered. Using the external converter was breaking a line or the loop of D50 having two usb cables connected at the same time, one for the power and one for signal transmission. Once they were isolated or detached, the sound of the D50 was much better.
I remember reading a long time ago about simple solution of noisy usb by using a powered usb hub. I found one laying around unused for years, connected the D50 to the powered usb hub and then connected it to MacBook. To my astonishment the sound changed considerably for better. The D50 lost the hardness, the mids came forward making the sound more engaging, the bass came wider and with more space around the notes, loosing the droning forwardness which was present before and most important, the soundstage got compact. Everything is now more connected, it might sound like a narrower on first listening but it feels more right. Without the usb hub, the soundstage was very wide but hollow in the middle and not deep. I would say that the D50 connected directly to the Mac sounds more V-shaped to me, while connected through the usb hub sounds more linear.
I am pleasantly surprised with the cheap solution. So basically if interested to try, you might buy one of these:
https://www.amazon.de/Hama-2-0-Hub-Netzteil-USB-Kabel-kompatibel/dp/B003E3R1KM?th=1
No need to buy the the USB3.0 since D50 doesn't support it.

On another side it is interesting to investigate further the problem with the THD compensation in the new es9038 chips. There are many reports that this setting changes the sound for better or worse as reported with the Pro-Ject Pre Box S2 digital. Topping's techs haven't incorporated in the menu this setting to be user-switchable nor we know exactly if this compensation is by default on or off. It could be the cause of the sound coloration present, since it changes the presence of the 2nd and 3rd harmonic.
https://www.audiosciencereview.com/...ect-pre-box-s2-digital.2370/page-4#post-66480

I had similar problem with my other DAC/amp ,someone mention this in one of the you tube vids,I was very satisfied with this cheap solution (USB HUB ),yes it sounds pretty natural and dead silent
BTW,iirc you can only have two DACs connected to the same HUB after that it will start splitting bit rate,I'm not sure this is insulation problem or Windows compatibility but decent USB cable seams to help also

 

[lacknothing]

Had the D50 for some testing and in case someone might be interested, I share my audition impressions here.

In short, its a step up compared to a cheap modified single clock TEAC in terms of dynamics and resolution, but its quite a step back in musicality with its hard, technical sound signature.


The long version:

As there was no PS included, I hooked it to a random 5V USB charger as well as to a pure LiFePO battery supply which has its output paralled with 1000uF Nichicon FC (no regulation whatsoever, just 2 diodes to get down to +5V, fully isolated from mains).

USB signal was fed directly from a Laptop and went through the Intona 1kV and 2.5kV isolator.

Beginning with the effect which the Intona 1kV versus 2.5kV USB isolator has on the presentation, its quite remarkable that - given the excellent measurement results of the D50 shown elsewhere - also in this setup the 1kV isolator yields considerable improvement in overall clarity but the 2.5kV version even is quite a step ahead.

Feeding the D50 by a standard 5V USB charger with display, I noticed that the current draw of the D50 is around 450mA. So no problem, as those can easily output 1.5A

Rolling the USB power supply to the battery power, its been immediately obvious that the D50 does respond heavily to the signature of any PS, which is no good sign for me at all.

The USB power supply yields a shouty presentation which at first my appear to be "fresh" but very very soon gets fatiguing. Piano passages for example always sound, as if there are only trash pianos from the ancient wild west films on each on every recording.

Switching to battery power the technical hardness in presentation gets tamed, but the underlying signature is still the same and also the sound is becoming a bit too mellow.

Looking closer to transient passages, I noticed another strange effect.
Adjusting volume by up-streams Daphile and let the D50 at its max volume, provided a distinctive clearer presentation than vice versa. In the current setup, my listening level with the D50 was about -12dB down full scale.

Most apparent to me was this behaviour in the tail of hard hit piano notes, which becomes distorted right away.
Any other music with high transient content showed the same signature though.

My last observation with the D50 was, that it seems to hiss-up at transients, but I already was too uninterested in this device to fully trace that down.



Well, as for me, the D50 besides its excellent technical specs and measurements certainly is not a keeper. This ESS DAC design would need way more modification surgery than I am willing to invest.

For what its worth.

 

[carlmart]

I am doing a bit research to assemble a pair of short cables (0.5m) minus the power wire. Not sure if that is necessary.

 

[bogi]

I am doing a bit research to assemble a pair of short cables (0.5m) minus the power wire. Not sure if that is necessary.

4 wires of USB2.0 are DATA+, DATA-, VBUS (+5V) and ground. Google for pictures of "USB type A" and "USB type B" connectors. Create as short cable as you can, since the best cable is no cable. For D50 you don't need the VBUS wire so only 3 wires are remaining. Make the ground wire a bit longer and lead it some centimeters distantly from DATA+ and DATA- wires.

 

[lacknothing]

Wondering why would the USB input sound so much worse than the spdif and why would connecting an external usb to spdif converter like SMSL x-usb II bring so much improvement while using the very same xmos as already built in the D50, I think I came to the solution.

I am pleasantly surprised with the cheap solution. So basically if interested to try, you might buy one of these:
https://www.amazon.de/Hama-2-0-Hub-Netzteil-USB-Kabel-kompatibel/dp/B003E3R1KM?th=1

Thanks for sharing.
I ordered this hub right away.

Did I understand you right that you also power the D50 from this USB hub?
So, two cables from the HAMA hub to the D50, one for USB signal one for +5V power?

 

[carlmart]

Make the ground wire a bit longer and lead it some centimeters distantly from DATA+ and DATA- wires.

I don't quite get your suggestion and/or understand it. How do I assemble this longer ground wire, and for what purpose?

 

[andrewinukm]

It would have sense to cut the +5V VBUS wire at the USB B type connector, so the high frequency noise from it would not influence data wires along the cable. When external power is not needed, such solution is better than substituting one power source with other.

USB B type adapter on this product strips +5V wire on the female side of the adaptor:

Just plug your current USB cable into the female side of the USB B type adaptor.
The USB type A branch of this product is intended to be used to inject clean power, but with D50 is not needed, since D50 does not require external power. You can simply let it unused.
https://www.audiophonics.fr/en/vari...e-for-external-usb-a-power-supply-p-8389.html

Cut a piece of tape to cover contact points 1 & 4. No need to buy a new accessory, or DIY a new cable yet. It's simple and fast, and you could try it immediately... unless you don't have tape. In which case, go buy it from a store.

Had the D50 for some testing and in case someone might be interested, I share my audition impressions here.

In short, its a step up compared to a cheap modified single clock TEAC in terms of dynamics and resolution, but its quite a step back in musicality with its hard, technical sound signature.


The long version:

As there was no PS included, I hooked it to a random 5V USB charger as well as to a pure LiFePO battery supply which has its output paralled with 1000uF Nichicon FC (no regulation whatsoever, just 2 diodes to get down to +5V, fully isolated from mains).

USB signal was fed directly from a Laptop and went through the Intona 1kV and 2.5kV isolator.

Beginning with the effect which the Intona 1kV versus 2.5kV USB isolator has on the presentation, its quite remarkable that - given the excellent measurement results of the D50 shown elsewhere - also in this setup the 1kV isolator yields considerable improvement in overall clarity but the 2.5kV version even is quite a step ahead.

Feeding the D50 by a standard 5V USB charger with display, I noticed that the current draw of the D50 is around 450mA. So no problem, as those can easily output 1.5A

Rolling the USB power supply to the battery power, its been immediately obvious that the D50 does respond heavily to the signature of any PS, which is no good sign for me at all.

The USB power supply yields a shouty presentation which at first my appear to be "fresh" but very very soon gets fatiguing. Piano passages for example always sound, as if there are only trash pianos from the ancient wild west films on each on every recording.

Switching to battery power the technical hardness in presentation gets tamed, but the underlying signature is still the same and also the sound is becoming a bit too mellow.

Looking closer to transient passages, I noticed another strange effect.
Adjusting volume by up-streams Daphile and let the D50 at its max volume, provided a distinctive clearer presentation than vice versa. In the current setup, my listening level with the D50 was about -12dB down full scale.

Most apparent to me was this behaviour in the tail of hard hit piano notes, which becomes distorted right away.
Any other music with high transient content showed the same signature though.

My last observation with the D50 was, that it seems to hiss-up at transients, but I already was too uninterested in this device to fully trace that down.



Well, as for me, the D50 besides its excellent technical specs and measurements certainly is not a keeper. This ESS DAC design would need way more modification surgery than I am willing to invest.

For what its worth.

Wow! You've got good ears.
I've never bothered to compare the volume control from Foobar vs D50. Maybe it's time to give it a good to see if what you observed is applicable in my setup as well.

And also the high transient issue. Can you describe it more?

 

[carlmart]

Let me see. What the USB cable seems to be is a balanced connection, with a hot (D+), cold (D-) and ground. It seems you can't eliminate ground.

 

[439598]

Probably the final mod for the D50 is upgrading the DAC clock and this is an essential mod, the difference is very noticeable and while not the same, feels comparable to upgrading the op amp supply, considering clock upgrades have very little discussion online with a lot arguing its a waste of money/time (hence why it was left till last) this is very surprising.

it requires delicate soldering and a cut trace but it's just soldering a couple of wires

The test pad is marked ''100M'' (100MHz, the clock speed) and sits between the op amp stage and the DAC chips (check carlmart's image for guidance if needed), the small silver rectangle is the clock/XO, you must cut the trace from ''100M'' testpad where it enters this clock and connect the output from the new clock to testpad, hook up power and ground to the clock and thats it.

I chose this clock. its a TCXO (temperature compensated) with very good phase noise and jitter measurements, (apparently the most important spec for audio) there are conflicting reports as to whether or not a TCXO provides any benefit for audio, I decided to get since the UDA38Pro uses one and it could be contributing to how it sounds, very very pleased with the result but cant say if this is due to temperature compensation. its very small, just about big enough to solder by hand but pretty finicky

this clock is another choice, its an XO with strong following in the DIY community, phenomenal phase noise performance for the price, about 3 times better than the above TCXO but 100 times poor temperature stability, a bit lower in cost and big enough that soldering shouldnt be too difficult.

 

[439598]

Let me see. What the USB cable seems to be is a balanced connection, with a hot (D+), cold (D-) and ground. It seems you can't eliminate ground.

while true you cant eliminate it entirely, people have discovered that ground only needs to be connected to form the link between an async DAC and PC as soon as the USB cable is plugged, after that you can disconnect it. apparently it can improve sound but I havent found a simple way to do this without destroying a USB cable.

 

[DjBobby]

The USB power supply yields a shouty presentation which at first my appear to be "fresh" but very very soon gets fatiguing. Piano passages for example always sound, as if there are only trash pianos from the ancient wild west films on each on every recording.

Most apparent to me was this behaviour in the tail of hard hit piano notes, which becomes distorted right away.
Any other music with high transient content showed the same signature though.

That was exactly my impression and that's why I was wondering if it has something to do with the newly applied setting in the es9038 called total harmonic distortion compensation.
Listening to several piano concertos, piano solos sounded like a honky-tonk piano, something which is mostly associated with an overly present 3rd harmonic. Also hissing on the transients was very obvious but mostly with the violin sound, where the violin would just kind of overdrive on high peaks. I have few other units with a previous versions of the ESS Sabre chip ES9018k2m and ES9028q2m which didn't show this anomalies.
Still, I was wondering how do the fabulous measurements of the D50 correspond with my personal subjective impressions. I took Mahler's 5th symphony with Vienna Phil/Bernstein and listened through. As long the music was simpler in texture with not many dynamic peaks and thick instruments, it sounded OK. When the music got more complex and the orchestra got very busy, the D50 lost the track and started to sound messy and much less clear.
I guess the standard measurements procedure using fixed frequency sine waves might measure great, but don't depict the real music performance situation, where the complex signal with different dynamics over high range of frequencies and different high speed transients, might provoke completely different behavior of the dac.

Thanks for sharing.
I ordered this hub right away.

Did I understand you right that you also power the D50 from this USB hub?
So, two cables from the HAMA hub to the D50, one for USB signal one for +5V power?

Haven't tried that yet, might later give a try. I was using a separate switch power supply, one which came originally with the SMSL M8a, and the usb hub only for the usb audio signal.

 

[andrewinukm]

Let me see. What the USB cable seems to be is a balanced connection, with a hot (D+), cold (D-) and ground. It seems you can't eliminate ground.

I've tried taping both +5V and ground on my Type-A plug --> it still works. Cutting off ground does not affect its operation.

Probably the final mod for the D50 is upgrading the DAC clock and this is an essential mod, the difference is very noticeable and while not the same, feels comparable to upgrading the op amp supply, considering clock upgrades have very little discussion online with a lot arguing its a waste of money/time (hence why it was left till last) this is very surprising.

it requires delicate soldering and a cut trace but it's just soldering a couple of wires

The test pad is marked ''100M'' (100MHz, the clock speed) and sits between the op amp stage and the DAC chips (check carlmart's image for guidance if needed), the small silver rectangle is the clock/XO, you must cut the trace from ''100M'' testpad where it enters this clock and connect the output from the new clock to testpad, hook up power and ground to the clock and thats it.

I chose this clock. its a TCXO (temperature compensated) with very good phase noise and jitter measurements, (apparently the most important spec for audio) there are conflicting reports as to whether or not a TCXO provides any benefit for audio, I decided to get since the UDA38Pro uses one and it could be contributing to how it sounds, very very pleased with the result but cant say if this is due to temperature compensation. its very small, just about big enough to solder by hand but pretty finicky

this clock is another choice, its an XO with strong following in the DIY community, phenomenal phase noise performance for the price, about 3 times better than the above TCXO but 100 times poor temperature stability, a bit lower in cost and big enough that soldering shouldnt be too difficult.

Awesome stuff!
I saw 4 clocks on the board: 3 near the XMOS, 1 for the DAC. In the LKS MH-DA003 thread, guys there changed the clocks to Pulsar clocks (crazy expensive and accurate).

Thanks for the links to the clocks. I was looking into NDK clock (the one used by WaveIO USB board), but they don't have 100MHz.
There's also the Crystek 957 which is the more expensive version of 575.

That was exactly my impression and that's why I was wondering if it has something to do with the newly applied setting in the es9038 called total harmonic distortion compensation.
Listening to several piano concertos, piano solos sounded like a honky-tonk piano, something which is mostly associated with an overly present 3rd harmonic. Also hissing on the transients was very obvious but mostly with the violin sound, where the violin would just kind of overdrive on high peaks. I have few other units with a previous versions of the ESS Sabre chip ES9018k2m and ES9028q2m which didn't show this anomalies.
Still, I was wondering how do the fabulous measurements of the D50 correspond with my personal subjective impressions. I took Mahler's 5th symphony with Vienna Phil/Bernstein and listened through. As long the music was simpler in texture with not many dynamic peaks and thick instruments, it sounded OK. When the music got more complex and the orchestra got very busy, the D50 lost the track and started to sound messy and much less clear.
I guess the standard measurements procedure using fixed frequency sine waves might measure great, but don't depict the real music performance situation, where the complex signal with different dynamics over high range of frequencies and different high speed transients, might provoke completely different behavior of the dac.


Haven't tried that yet, might later give a try. I was using a separate switch power supply, one which came originally with the SMSL M8a, and the usb hub only for the usb audio signal.

Hmmm, I've not really listened to piano songs since then. Perhaps subconsciously it doesn't sound right.

 

[bogi]

I don't quite get your suggestion and/or understand it. How do I assemble this longer ground wire, and for what purpose?

I meant to use a separate wire for ground.
The differences we can hear with different USB cables are all about noise from the audio source. Not only the +5V VBUS line, but also computer ground is polluted by noise. From this reason some 'audiophile' USB cables isolate data wires from power wires, although it need not to be visible.