[lacknothing]

I absolutely believe you that it improves the USB input of the D50 significantly. I am only wondering if there is a logic of investing $325 to improve the unit which costs $250 or less. It makes a total of $575, for which might one simply jump to a higher tier dac.

As long as there is no proven way to correlate meaningful measurements with what an USB isolator does for the DAC's SQ, it remains to the user to detect and value (or not) any improvements.

As one chooses to go with the Intona, I suggest that you go with the even more expensive 2.5kV version, I just got to compare it with the 1kV version I have. IMO the improvement in SQ scales up quite nicely, though neither of these device was specifically built for audio application.

 

[lacknothing]

The internal power supply marked ''USB3.3V" on the PCB is powering the XMOS chip but also some other critical part of the DAC, removing the zero ohm link for ''USB3.3V'' will cause the DAC to stop working so the only way to disable internal XMOS chip only is by removing multiple very small 0 ohm links close to the XMOS chip itself, there is 3 in total.

Possibly have a picture?
From what you outline, for modders it might be a good idea to feed the XMOS by a separate regulated rail?
What you think? Which are the 0 ohm links for GND and +V ?

 

[439598]

Possibly have a picture?
From what you outline, for modders it might be a good idea to feed the XMOS by a separate regulated rail?
What you think? Which are the 0 ohm links for GND and +V ?

links are marked in the pic, these are all V+, XMOS chip has multiple power input pins.
The ''USB3.3V'' power section for XMOS chip, along with the DAC power sections next to it, use linear regulators to drop the 5V input to 3.3v.
Provided the 5V input is clean this should perform fine, its not a real problem like the op amp power supply but thats not to say it cant be improved with a better performing regulator. So far I switched from these internal regulators to using ultra low noise 3.3v LT3045 regulators for the DAC chips supply and there was a definite improvement there.

 

[carlmart]

What were the resistors you cut-off for using the LT3045s on the DACs (both)?

Down below to the left and to the right we can see shielded inductors, marked 2R2 and 4R7. Are they inductors or power resistors?

How does Topping power the output OPAs? How and how higher do they go in DC voltage?

 

[439598]

What were the resistors you cut-off for using the LT3045s on the DACs (both)?

Down below to the left and to the right we can see shielded inductors, marked 2R2 and 4R7. Are they inductors or power resistors?

How does Topping power the output OPAs? How and how higher do they go in DC voltage?

I think most of thats been answered already in the thread. As for the inductors, I dont know.

 

[harry501501]

Anyone able to compare this with the Topping nX4 for SQ?

 

[califmike33]

What is the firmware update supposed to do where do I find the firmware update?

 

[califmike33]

Anyone able to compare this with the Topping nX4 for SQ?

I had the NX4 the sound quality is good on the nx4 it's better on the D50.

 

[andrewinukm]

I absolutely believe you that it improves the USB input of the D50 significantly. I am only wondering if there is a logic of investing $325 to improve the unit which costs $250 or less. It makes a total of $575, for which might one simply jump to a higher tier dac.

Nope, there really is no logic to it. I happen to chance upon a good deal for ISO Regen. I may upgrade and sell the D50 in the future, but I will keep the ISO Regen for the future DAC.

Has anyone compared the Intona or the Regen with the Hifime isolator? Measuring and listening, of course.

I compared to W4S Recovery to ISO Regen. W4S's effect was less significant, and I really am not sure the difference between with vs without W4S in the chain is placebo or not. It was too minor to confirm. ISO Regen's effect was easily heard.

On various other listening tests:
Out of 4 persons (on difference occasions) that have listened to my setup with vs without ISO Regen, all 4 heard a difference and all agreed that the focus, details, and clarity improved. 3 preferred the ISO Regen, 1 preferred no ISO Regen despite saying that ISO Regen is "technically" better. He preferred the warmth and body without ISO Regen, and ISO Regen was "too clean" (note: my setup has very little bass, so any additional warmth makes it sounds more attractive).

 

[lacknothing]

all 4 heard a difference and all agreed that the focus, details, and clarity improved.

Same here with the Intona plus my feeling of expanded dynamic range, improvements on PRAT and musicality (whatever this may mean to you).

 

[carlmart]

I think most of that's been answered already in the thread. As for the inductors, I don't know.

You have been the person that has been looking into the D50 innards and apparently used external LT3045 regulators somewhere. Where and how should interesting to know.

Many questions are still unanswered, I've just looked into that.

First thing would be to know what chips are those marked with "?". U9 and U10, in yellow squares on upper image, seem to be booster regulators The one on the right probably feeds +/-8v to the output trio opamps. The one on the left I don't know what it does.

There's also a chip on the lower image, above the XMOS, that would be interesting the name of, to see what it does.

The yellow rectangular caps are probably tantalum types, which I personally do not like too much. Space is critical, so replacing them with electrolytics would be difficult. But disconnecting any series resistors to the OPA1612s, and using external linear regulation, might be nice.

This power supply upgrade, "linearizing" XMOS, DAC and output chips supplies, should be a first step.

Replacing the XMOS USB to I2S interface seems a bit hard to implement, from what was described.

It would be useful to know what is used to regulate the several 3.3v feeds.

 

[439598]

You have been the person that has been looking into the D50 innards and apparently used external LT3045 regulators somewhere. Where and how should interesting to know.

Many questions are still unanswered, I've just looked into that.

First thing would be to know what chips are those marked with "?". U9 and U10, in yellow squares on upper image, seem to be booster regulators The one on the right probably feeds +/-8v to the output trio opamps. The one on the left I don't know what it does.

There's also a chip on the lower image, above the XMOS, that would be interesting the name of, to see what it does.

The yellow rectangular caps are probably tantalum types, which I personally do not like too much. Space is critical, so replacing them with electrolytics would be difficult. But disconnecting any series resistors to the OPA1612s, and using external linear regulation, might be nice.

This power supply upgrade, "linearizing" XMOS, DAC and output chips supplies, should be a first step.

Replacing the XMOS USB to I2S interface seems a bit hard to implement, from what was described.

It would be useful to know what is used to regulate the several 3.3v feeds.

the LT3045 were used for the DAC chip as I said, you can see in the pic where the internal DAC power is connected by the markings on the PCB although I recommend having your own D50 to look at first, that should makes things clearer.
https://www.head-fi.org/threads/topping-d50.876669/page-15#post-14563562
https://www.head-fi.org/threads/topping-d50.876669/page-15#post-14566791

and I dont recommend upgrading DAC power supply, its not necessary. I was already using the <1uV noise LT3045 for the main 5V input so it was a waste not to drop to it to 3.3V and bypass the internal 9uV noise 3.3V regulators. There was an audible improvement but not worth the hassle, risk and cost of using LT3045.

 

[andrewinukm]

You have been the person that has been looking into the D50 innards and apparently used external LT3045 regulators somewhere. Where and how should interesting to know.

Many questions are still unanswered, I've just looked into that.

First thing would be to know what chips are those marked with "?". U9 and U10, in yellow squares on upper image, seem to be booster regulators The one on the right probably feeds +/-8v to the output trio opamps. The one on the left I don't know what it does.

There's also a chip on the lower image, above the XMOS, that would be interesting the name of, to see what it does.

The yellow rectangular caps are probably tantalum types, which I personally do not like too much. Space is critical, so replacing them with electrolytics would be difficult. But disconnecting any series resistors to the OPA1612s, and using external linear regulation, might be nice.

This power supply upgrade, "linearizing" XMOS, DAC and output chips supplies, should be a first step.

Replacing the XMOS USB to I2S interface seems a bit hard to implement, from what was described.

It would be useful to know what is used to regulate the several 3.3v feeds.

One of the regulated power should be for the display and controller chip/circuit, which i suspect the left chip is the Vreg for the the display/controller chip (right chip).

the LT3045 were used for the DAC chip as I said, you can see in the pic where the internal DAC power is connected by the markings on the PCB although I recommend having your own D50 to look at first, that should makes things clearer.
https://www.head-fi.org/threads/topping-d50.876669/page-15#post-14563562
https://www.head-fi.org/threads/topping-d50.876669/page-15#post-14566791

and I dont recommend upgrading DAC power supply, its not necessary. I was already using the <1uV noise LT3045 for the main 5V input so it was a waste not to drop to it to 3.3V and bypass the internal 9uV noise 3.3V regulators. There was an audible improvement but not worth the hassle, risk and cost of using LT3045.

9uV noise is really good already. I agree that it's not worth necessary to upgrade to LT3045.

 

[DjBobby]

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

 

[carlmart]

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