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Topping E30 powersupply/USB noise

CTheCurious

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Hi everyone, I just want to expose a problem I have with my Topping E30, the way I temporary solved it and where I think I can get better. Plus I want to know your thoughts and opinions.

Configuration:
I plugged my DAC to 2 USB, obviously 1 for power and 1 for data, on a USB hub that has it's own powersupply and is connected to my PC. The output of the E30 goes to a DarkVoice 336S.

The problem:
I could ear a countinuos noise, not too high but definitely annoying. At first I thought the problem was the DarkVoice, but then I had the luck to test it with another source and the noise wasn't there at all, so I tried to work on the E30. I plugged a powerbank to it and it seemed to attenuate the problem but didn't solve it, so i tried to unplug the data USB and the noise disappeared. I then plugged a Toslink cable to the PC and DAC and now I'm fine. If I replug the power to the USB hub or to my PC the noise still reapperas, anyway I guess it may be a groundloop.

What I want to do next:
First I can't use the powerbank forever so I want to replace it with a decent 5v powersupply and this should solve one part of the problem.
Second, since the toslink has it's own limitations compared to USB, I want to find another solution to that as well. Even plug it directly to the motherboard didn't solve anything at all. I saw some USB Isolators and filters but I don't trust them too much.

This is the powersupply I was thinking to use.

Or maybe this one.

What do you think about it? What would you do/try?
 
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bravomail

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First I can't use the powerbank forever so I want to replace it with a decent 5v powersupply and this should solve one part of the problem.
Second, since the toslink has it's own limitations compared to USB, I want to find another solution to that as well. Even plug it directly to the motherboard didn't solve anything at all. I saw some USB Isolators and filters but I don't trust them too much.

This is the powersupply I was thinking to use.

Or maybe this one.

What do you think about it? What would you do/try?
definitely use a separate cheap USB powersupply.
What are TOSLINK issues u r having? Is it length? Sampling frequency? - leave it at highest 24/96.
 

Χ Ξ Σ

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Screen Shot 2021-11-22 at 11.04.54 AM.png
 

audio2design

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Didn't know they had these. Going to order a couple. The ones I have now are $300+. I have used them in my audio system, but they often find themselves in the lab too. I can usually get away with the low speed ones, but sometimes you need high speed. They are good in lower cost ADC systems as well if they are not isolated (many are not).
 

audio2design

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What I want to do next:
First I can't use the powerbank forever so I want to replace it with a decent 5v powersupply and this should solve one part of the problem.
Second, since the toslink has it's own limitations compared to USB, I want to find another solution to that as well. Even plug it directly to the motherboard didn't solve anything at all. I saw some USB Isolators and filters but I don't trust them too much.

Not necessarily. Meanwell is "well known", but really there is nothing special about their products. This may fix your issue. It may not. The power bank is isolated, which is likely the reason for much of the attenuation. Unfortunately you really don't know till you try. I think the isolator above is a great idea and you likely can at that point use a fairly basic supply.
 

Χ Ξ Σ

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Didn't know they had these. Going to order a couple. The ones I have now are $300+. I have used them in my audio system, but they often find themselves in the lab too. I can usually get away with the low speed ones, but sometimes you need high speed. They are good in lower cost ADC systems as well if they are not isolated (many are not).
It's a new product, hence not being included in Black Friday sales, but you can let the product sit in your cart for a day and Shenzhenaudio will send you a coupon code. I believe HiFiGo does the same.
 
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CTheCurious

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definitely use a separate cheap USB powersupply.
What are TOSLINK issues u r having? Is it length? Sampling frequency? - leave it at highest 24/96.

I would not call them issues, more limitations on sampling, bandwidth and some software side features. Obviously I could leave it as it is but I would prefer to solve the problem on the USB anyway.

Not necessarily. Meanwell is "well known", but really there is nothing special about their products. This may fix your issue. It may not. The power bank is isolated, which is likely the reason for much of the attenuation. Unfortunately you really don't know till you try. I think the isolator above is a great idea and you likely can at that point use a fairly basic supply.

Yes I guess I just have to try, unfortunately this week I'm outside for work so I have to wait until next week.
Just to be sure, because I never used one, these devices don't act on data + and data - but only on power and gnd, right?
 
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martytoo

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definitely use a separate cheap USB powersupply.
What are TOSLINK issues u r having? Is it length? Sampling frequency? - leave it at highest 24/96.
This is an answer that I am looking for some detail.

I know that Amir has talked and written extensively on the lack of need for AC filters and such when feeding well designed audio gear. But the interesting thing about some (most?) of the Topping gear is that the they do not include the USB power supply wall wart. Many have written that to get the best out of their gear you should either use a power bank or spend another $50 to $150 for a high quality linear power supply.

Is this just another bottle of snake oil? The issue is slightly different from the need for an AC filter. You don't need an AC filter with a well designed power supply but when the manufacturer doesn't provide the AC to DC converter for the power supply I get lost in the argument regarding the need for a "HiFi Power Supply".
Thanks!
 

Berwhale

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Many have written that to get the best out of their gear you should either use a power bank or spend another $50 to $150 for a high quality linear power supply.


I should add that this didn't stop me purchasing a Topping P50 to power my D50s and A50s. I bought the P50 because I liked the look of the stack and it made my cabling much simpler (less PSU's, less cables to run through desk). Now that that the Topping x50 stack has been retired from my desk to my 'easy listening chair', another benefit has revealed itself: The P50 has enough USB sockets to power a Chromecast Audio in addition to the A50s and D50s.
 
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martytoo

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I should add that this didn't stop me purchasing a Topping P50 to power my D50s and A50s. I bought the P50 because I liked the look of the stack and it made my cabling much simpler (less PSU's, less cables to run through desk). Now that that the Topping x50 stack has been retired from my desk to my 'easy listening chair', another benefit has revealed itself: The P50 has enough USB sockets to power a Chromecast Audio in addition to the A50s and D50s.
Thanks. I'm not surprised he covered this. I couldn't find it!
 
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CTheCurious

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Little update. Right now, since I've bought a Topping A30PRO, I'm using the ground/lift switch on the rear of the unit to eliminate the ground loop.

It seemes it's working like a charm, with the switch positioned on ground I can ear the loop, on lift it disappears completely. For now I think I will use it like this.

Anyway I will continue to find a solution since the A30PRO it's not the only device I plan to use.
For the powersupply I'm still using the usb HUB, but soon I will do some changes so I will finally try a normal powersupply.
For the USB data transfer I'm tempted to solve the problem by finding the source of the groundloop.
 

Mart68

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This is an answer that I am looking for some detail.

I know that Amir has talked and written extensively on the lack of need for AC filters and such when feeding well designed audio gear. But the interesting thing about some (most?) of the Topping gear is that the they do not include the USB power supply wall wart. Many have written that to get the best out of their gear you should either use a power bank or spend another $50 to $150 for a high quality linear power supply.

Is this just another bottle of snake oil? The issue is slightly different from the need for an AC filter. You don't need an AC filter with a well designed power supply but when the manufacturer doesn't provide the AC to DC converter for the power supply I get lost in the argument regarding the need for a "HiFi Power Supply".
Thanks!
I use a spare mobile phone charger to power mine. Pugged into a 4 way power strip that plugs into the wall socket. No filters, regenerators or anything like that.

Sound quality is outstanding. I see what your saying but I've not found that any sort of fancy power supply is necessary.
 
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CTheCurious

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I use a spare mobile phone charger to power mine. Pugged into a 4 way power strip that plugs into the wall socket. No filters, regenerators or anything like that.

Sound quality is outstanding. I see what your saying but I've not found that any sort of fancy power supply is necessary.
Yes I think you're right, for the powersupply I should not need anything fancy, the USB is the main problem but before spending any money on filters I will do some tests to see if I can solve the loop.
 

Berwhale

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Anyway I will continue to find a solution since the A30PRO it's not the only device I plan to use.
For the powersupply I'm still using the usb HUB, but soon I will do some changes so I will finally try a normal powersupply.
For the USB data transfer I'm tempted to solve the problem by finding the source of the groundloop.

The presence or absense of a ground loop is likely to be dependent on the devices in use. i.e. the 'souce of the ground loop' is the whole system, not an individual component. For example, I had the following setup, which worked perfectly, with no ground loop noise....

PC USB -> Topping D50s/Topping A50s -> Tannoy Reveal 402 active monitors

I changed the monitors to iLoud MTMs and suddenly had a terrible ground loop issue. The reason is that the MTMs have a safety ground on their power connection. This provided a path to ground from the PC to the MTMs via the USB and RCA interconnects. The Reveal 402's did not have the issue because they have a 2-pin power connection and no safety ground.

In your case, the DarkVoice 336S has a 3-pin power connector (with safety ground) and therefore has the potential to introduce a ground loop into a system. The DarkVoice 336SE is also susceptable to mains hum (presumably the S is similar)...


Personally, I solved my ground loop in 3 ways:

1. Initially, I used a cheap USB Isolator between the PC and D50s - breaking the ground loop in the USB connection.

2. Then I installed SPDIF/Toslink header in my PC and switched to an optical connection - Electrically isolating the PC from the rest of the audio chain.

3. Finally, I replaced the D50s/A50s in my desktop setup with a Topping EX5 with balanced outputs - Removing the potential for ground loops between the DAC/Amp and monitors.
 
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CTheCurious

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The presence or absense of a ground loop is likely to be dependent on the devices in use. i.e. the 'souce of the ground loop' is the whole system, not an individual component. For example, I had the following setup, which worked perfectly, with no ground loop noise....

PC USB -> Topping D50s/Topping A50s -> Tannoy Reveal 402 active monitors

I changed the monitors to iLoud MTMs and suddenly had a terrible ground loop issue. The reason is that the MTMs have a safety ground on their power connection. This provided a path to ground from the PC to the MTMs via the USB and RCA interconnects. The Reveal 402's did not have the issue because they have a 2-pin power connection and no safety ground.

In your case, the DarkVoice 336S has a 3-pin power connector (with safety ground) and therefore has the potential to introduce a ground loop into a system. The DarkVoice 336SE is also susceptable to mains hum (presumably the S is similar)...


Personally, I solved my ground loop in 3 ways:

1. Initially, I used a cheap USB Isolator between the PC and D50s - breaking the ground loop in the USB connection.

2. Then I installed SPDIF/Toslink header in my PC and switched to an optical connection - Electrically isolating the PC from the rest of the audio chain.

3. Finally, I replaced the D50s/A50s in my desktop setup with a Topping EX5 with balanced outputs - Removing the potential for ground loops between the DAC/Amp and monitors.

Yep, I think this is a great example.
 

Berwhale

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In my experience, Toslink is the worst way - probably because it causes jitter.

Toslink doesn't 'cause jitter'. Toslink is suspectible to jitter because the clock signal is embedded in the data signal and has to be extracted and reconstructed at the receiver. There is no difference between SPDIF and Toslink in this respect (the same clock and data signal is transmitted for both physical transports).

Lots more about jitter here: http://nwavguy.blogspot.com/2011/02/jitter-does-it-matter.html

I could not detect audible differences between any of the various ways I had the D50s connected to my PC.
 

bh69

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I tried connect notebook to my DAC over TOSLINK and result was significatly worse than USB.

I don't understand what you mean that clock signal is reconstructed at the receiver ? While it's synchronous transfer, it must be sensitive to timing problems (SPDIF has the same problem, but it's used with audio gear like CD player, so there are probably much less problems as from PC. TOSLINK from CD player would be probably better than from notebook/PC). Asych USB is the best way to play from PC.
 

Lambda

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I don't understand what you mean that clock signal is reconstructed at the receiver
most likely. It is all in your head ;)
But if not you can measure it wit REW or something and show us...
so I tried to work on the E30. I plugged a powerbank to it and it seemed to attenuate the problem but didn't solve it, so i tried to unplug the data USB and the noise disappeared
You can try grounding the USB hub "Ground".

But over all very disappointing to hear another "high end" product being so susceptible to noise from the USB port.
And also sad There is no testing for this USB port "isolation" in the reviews.

No one hears the difference between SINAD of 115 and 120dB but this problem is kind of obvious and annoying for many customers.
Yet it would be very easy and cheap for the manufacturer to make the DAC (mostly) immune to noise form the usb port.

Selling an Separate USB isolator is a strange after thought.
This could and shuld be included in the devices for cents.



Conclusions
It is clear that whether you use the USB power, or the supplied switching power supply, there is absolutely no audible improvement in the output of the DAC with linear power supplies. One can help himself believe otherwise by looking at the noise spectrum alone as I have shown in the last graph. But again, we don't listen to power supply wires. Those waveforms go through filtering stages even in cheapest DACs.
The same Conclusion he had for USB isolatos
and for cables...
don't know how he can make this conclusion if he was not able to reproduce the problem many experience.

You don't need an "linear" power supply You need an Low noise power supply with low common mode capacitance or High impedance.
It just happens to be many linear power supply's are low noise and have high impedance to mains.

As OP is experiencing the DAC is clearly not doing well with noise coming from the USB port.
A USB Isolator with an Low noise power supply would help.

Better RCA cables would maybe Help.

Are the USB ports properly grounded to the PC case? is this a DIY pc or from a big manufacturer (who actually dose EM compliance testing)
 
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