Review and Measurements of Topping DX3Pro DAC and Headphone Amp

[da Choge]

US version with a EU adaptor (2-pole).

Somebody with better knowledge than me - please correct me if I'm wrong, but I don't think you can run a US 110 VAC 60 Hz unit on european 220V 50 Hz power by just using a simple adapter -- you would actually need a step-down transformer. Don't know if the the DX3Pro has dual-country capable power inlet, but if it doesn't, Artburda, you could be slowly burning out your unit. My US DX3Pro runs very cool, even when playing. Using it with an incorrect mains supply could cause it to run very hot. Maybe I'm missing something . . .

 

[ZenTraveler]

Yes, by turned off I meant in standby mode. And the USB port is not in "always on mode", so when I turn off the laptop, even though it's always plugged in because I use it without the battery, nothing happens when I plug in an iPhone/iPod.

Unfortunately, I'm not very knowledgeable in the field of electric engineering, but maybe there is still some sort of current flowing from the laptop through the DX3 or vice versa. I am saying this, because I noticed when the DX3 is only plugged into the socket and unplugged from the laptop, you can feel a contact current when touching the DX3's surface. I guess this is the case since it only has a 2-pole adaptor. The laptop an the other hand has a 3-pole adaptor and when the DX3 is connected to the laptop by USB the contact current on the DX3's surface disappears.

Maybe the contact current/ leakage current is responsible for the warmth of the DX3's casing and a 3-pole adaptor power supply for the DX3 would solve this warmth problem...

I believe it's USB is always on mode, whenever I turn on my PC the DX3 will detect it and turn on by itself.

Mine is with 3 pole adaptor and when in standby with USB attached to PC it still feel warm, if I remove the USB cable it become less warm. But it doesn't have contact current no matter USB cable were plug in or not. Mine is V2. It is just a bit warm feel, not as hot as when playing sound through it. I think there's some that write before V1 leak current.

 

[ZenTraveler]

Somebody with better knowledge than me - please correct me if I'm wrong, but I don't think you can run a US 110 VAC 60 Hz unit on european 220V 50 Hz power by just using a simple adapter -- you would actually need a step-down transformer. Don't know if the the DX3Pro has dual-country capable power inlet, but if it doesn't, Artburda, you could be slowly burning out your unit. My US DX3Pro runs very cool, even when playing. Using it with an incorrect mains supply could cause it to run very hot. Maybe I'm missing something . . .

At the adapter itself will write what current it support but most Chinese manufactured products these days will support both as they sell it to all countries. My adapter written it support 100~240.

 

[Veri]

Somebody with better knowledge than me - please correct me if I'm wrong, but I don't think you can run a US 110 VAC 60 Hz unit on european 220V 50 Hz power by just using a simple adapter

Most switching power supplies are universal voltage, 110-230V compatible. So a simple adapter should definitely work.

 

[BDWoody]

Most switching power supplies are universal voltage, 110-230V compatible. So a simple adapter should definitely work.

Is there a situation where 50 vs 60 Hz would need to be considered?

 

[Veri]

Is there a situation where 50 vs 60 Hz would need to be considered?

good question but I don't think so. best to always read the label, most are like this:

 

[da Choge]

Most switching power supplies are universal voltage, 110-230V compatible. So a simple adapter should definitely work.

My bad; didn't check my unit's PS and really didn't realize that most SMPSs are capable of taking both voltages. So, Artburda, it looks like the PS is likely not the reason your unit runs hot. Sorry for the misdirection.

 

[Floris]

Hey guys,

Been loving the DX3 Pro (V2 according to Drop, shipped in Dec 2019) I picked up during my trip to the US... Until the remote stopped working. It's the RC-15A with the two AAA batteries, it does seem to be emitting light when I point my camera at it, so it must be the receiver?

I've emailed Drop about it and, in turn, they're asking Topping about it. Until I hear back from them in a few days, has anyone had a similar problem and solved it? I've made sure that the batteries I put in were fresh Alkaline ones, but to no avail either.

I really don't want to have to send this thing back, I bet the return process is going to be dreadful.

Thanks lads.

 

[artburda]

My bad; didn't check my unit's PS and really didn't realize that most SMPSs are capable of taking both voltages. So, Artburda, it looks like the PS is likely not the reason your unit runs hot. Sorry for the misdirection.

No problem da Choge. But I still think it has something to do with the power supply, since it gets warm when the power supply is plugged in regardless if the DX3 is on or in standby mode and/or connected to another device. What could be an explanation? Or is it even harmful for the DX3 regarding longevity?

 

[Toku]

Hey guys,

Been loving the DX3 Pro (V2 according to Drop, shipped in Dec 2019) I picked up during my trip to the US... Until the remote stopped working. It's the RC-15A with the two AAA batteries, it does seem to be emitting light when I point my camera at it, so it must be the receiver?

I've emailed Drop about it and, in turn, they're asking Topping about it. Until I hear back from them in a few days, has anyone had a similar problem and solved it? I've made sure that the batteries I put in were fresh Alkaline ones, but to no avail either.

I really don't want to have to send this thing back, I bet the return process is going to be dreadful.

Thanks lads.

Did you press the remote control C button first before operating?

 

[tdastrup]

Hey guys, I really need some help figuring this out. It's driving me crazy. I have an audible buzzing (around 980 Hz) coming out of my powered monitors when USB is connected to my desktop computer. My setup is as follows:

DX3 Pro is in preamp mode connected with RCA cables (BlueJeans) to Kali LP-6 powered studio monitors. Power for the DX3 Pro (topping provided power cable) and both Kali monitors is plugged into a 3-outlet extension cord which is plugged directly into a wall outlet (US - 120v). The DX3 Pro is, of course, also plugged into my computer (topping provided USB cable). My computer is water cooled so it has a pump and 6x 120mm fans. It has a Z390 Aorus Master motherboard powered by an EVGA SuperNOVA 750 G3 PSU. I have a pair of HD 6XX which playback flawlessly even using USB to my computer. There is no buzzing when using headphone out.

If I switch to any other input and leave the USB connected, the buzzing continues. If I unplug USB from my computer, the buzzing goes away. I can use optical to my computer just fine, but that's not a great long-term solution for me as I have a different source I want to use via optical. Bluetooth is fine; no buzzing. I don't have any coax output devices (that I know of), so not sure if the buzzing is present on coax.

At this point, I've tried so many different things. What's interesting is that the DX3 Pro via USB to two other laptops has no buzzing. That makes it seem like something with my computer. When I plug my HD 6XX or AKG earbuds into my computer, there is no buzzing. Same thing when I use a super cheep USB DAC and any headphones/buds. I had a 3.5 mm to RCA cable laying around so I connected it from my laptop to the Kali monitor and there was no buzzing. I connected the same cable to my PC and it goes straight to crap. The buzzing is at least twice as bad as it is when going through the DX3 Pro. If my computer was the problem, wouldn't I hear the buzzing in any headphones or through the other crap DAC? So, then maybe power related?

My computer was plugged into an APC UPS, but I've bypassed it which did nothing. I started looking into a P50 LPS thinking that would "clean the power" but after reading a little, doesn't seem like it would do much at all (am I wrong?). I even started looking into a DX7 Pro so that I could use balanced XLRs to my Kali monitors which would get rid of any noise introduced on the cable between the DAC and the monitors. I am doubting that's where this buzzing is coming from though and don't want to spend $600 and still have the problem. It seems like there is interference from the computer somehow being sent over the USB cable to my DX3 Pro. Having an external USB DAC is supposed to isolate all types of interference that's going on inside the computer though, isn't it? Back in the day if you could hear your mouse movements through your headphones, the fix was to get an external USB DAC. Which... DX3 Pro.

That got me thinking so I did some more tests. I turned the volume on my Kali monitors all the way up so the buzzing was as pronounced as possible and I was able to hear my mouse movements and scrolling and moving windows around. I then grabbed Cinebench to see if maybe loading the CPU changed anything and it did. The frequency of the buzzing lowered to around 780 Hz and actually got a little quieter. I did a 3D Mark GPU benchmark and it went absolutely crazy. I had the output on the DX3 Pro set to BT (not paired with anything), Windows muted, and the DX3 Pro device disabled under device manager. Even with all that, it sounded like I should have been getting a deep tissue massage.

All that makes me think there's some type of interference or current that is originating inside my computer, hitching a ride on the USB cable to my DX3 Pro, and somehow jumping over to the RCA output even when Line Out isn't selected, then being faithfully reproduced by my Kali monitors. First, how is this even possible, and second, how can I fix it? My motherboard has a feature specifically for audio equipment that won't send the 5v power out the USB port. It will send the data, but relies on the external device to power itself. I've tried that with my DX3 Pro, but it seems to require the 5v in order to function, even though it has its own power source. I just stumbled across USB isolators, but haven't looked into them at all yet. Snake oil or viable solution? Again, it isn't affecting the headphone output at all. I can't hear even the faintest trace of this interference, or whatever it is, through my HD 6XX while USB is connected to my computer. I'm completely lost and would very much appreciate any suggestions.

 

[pacman]

Hey guys, I really need some help figuring this out. It's driving me crazy. I have an audible buzzing (around 980 Hz) coming out of my powered monitors when USB is connected to my desktop computer. My setup is as follows:

DX3 Pro is in preamp mode connected with RCA cables (BlueJeans) to Kali LP-6 powered studio monitors. Power for the DX3 Pro (topping provided power cable) and both Kali monitors is plugged into a 3-outlet extension cord which is plugged directly into a wall outlet (US - 120v). The DX3 Pro is, of course, also plugged into my computer (topping provided USB cable). My computer is water cooled so it has a pump and 6x 120mm fans. It has a Z390 Aorus Master motherboard powered by an EVGA SuperNOVA 750 G3 PSU. I have a pair of HD 6XX which playback flawlessly even using USB to my computer. There is no buzzing when using headphone out.

If I switch to any other input and leave the USB connected, the buzzing continues. If I unplug USB from my computer, the buzzing goes away. I can use optical to my computer just fine, but that's not a great long-term solution for me as I have a different source I want to use via optical. Bluetooth is fine; no buzzing. I don't have any coax output devices (that I know of), so not sure if the buzzing is present on coax.

At this point, I've tried so many different things. What's interesting is that the DX3 Pro via USB to two other laptops has no buzzing. That makes it seem like something with my computer. When I plug my HD 6XX or AKG earbuds into my computer, there is no buzzing. Same thing when I use a super cheep USB DAC and any headphones/buds. I had a 3.5 mm to RCA cable laying around so I connected it from my laptop to the Kali monitor and there was no buzzing. I connected the same cable to my PC and it goes straight to crap. The buzzing is at least twice as bad as it is when going through the DX3 Pro. If my computer was the problem, wouldn't I hear the buzzing in any headphones or through the other crap DAC? So, then maybe power related?

My computer was plugged into an APC UPS, but I've bypassed it which did nothing. I started looking into a P50 LPS thinking that would "clean the power" but after reading a little, doesn't seem like it would do much at all (am I wrong?). I even started looking into a DX7 Pro so that I could use balanced XLRs to my Kali monitors which would get rid of any noise introduced on the cable between the DAC and the monitors. I am doubting that's where this buzzing is coming from though and don't want to spend $600 and still have the problem. It seems like there is interference from the computer somehow being sent over the USB cable to my DX3 Pro. Having an external USB DAC is supposed to isolate all types of interference that's going on inside the computer though, isn't it? Back in the day if you could hear your mouse movements through your headphones, the fix was to get an external USB DAC. Which... DX3 Pro.

That got me thinking so I did some more tests. I turned the volume on my Kali monitors all the way up so the buzzing was as pronounced as possible and I was able to hear my mouse movements and scrolling and moving windows around. I then grabbed Cinebench to see if maybe loading the CPU changed anything and it did. The frequency of the buzzing lowered to around 780 Hz and actually got a little quieter. I did a 3D Mark GPU benchmark and it went absolutely crazy. I had the output on the DX3 Pro set to BT (not paired with anything), Windows muted, and the DX3 Pro device disabled under device manager. Even with all that, it sounded like I should have been getting a deep tissue massage.

All that makes me think there's some type of interference or current that is originating inside my computer, hitching a ride on the USB cable to my DX3 Pro, and somehow jumping over to the RCA output even when Line Out isn't selected, then being faithfully reproduced by my Kali monitors. First, how is this even possible, and second, how can I fix it? My motherboard has a feature specifically for audio equipment that won't send the 5v power out the USB port. It will send the data, but relies on the external device to power itself. I've tried that with my DX3 Pro, but it seems to require the 5v in order to function, even though it has its own power source. I just stumbled across USB isolators, but haven't looked into them at all yet. Snake oil or viable solution? Again, it isn't affecting the headphone output at all. I can't hear even the faintest trace of this interference, or whatever it is, through my HD 6XX while USB is connected to my computer. I'm completely lost and would very much appreciate any suggestions.

I had the exactly same problem. My PC is older, an i5-2500K, but it's loaded with 240mm water pump, GTX 970 and sh*t.

The buzzing were worse when: 1- doing heavy writing tasks to SSD and 2- stressing the GPU (gaming).

Everything properly grounded etc. My monitors are KRK Rokit 5 G3. If I raise the volume to max, I could even hear the noise of moving the mouse.

Bought a DX7 Pro, switched to XLR balanced connections and all the buzz and fuzz are gone. To my experience, the only way to use noisy PCs as USB players to active monitors is going balanced.

 

[tdastrup]

I had the exactly same problem. My PC is older, an i5-2500K, but it's loaded with 240mm water pump, GTX 970 and sh*t.

The buzzing were worse when: 1- doing heavy writing tasks to SSD and 2- stressing the GPU (gaming).

Everything properly grounded etc. My monitors are KRK Rokit 5 G3. If I raise the volume to max, I could even hear the noise of moving the mouse.

Bought a DX7 Pro, switched to XLR balanced connections and all the buzz and fuzz are gone. To my experience, the only way to use noisy PCs as USB players to active monitors is going balanced.

After looking into USB isolators and ground loops, I did another test. I pulled an extension cable from another room whose outlets are on a different circuit breaker. When I did this, there was no buzzing. So, I ordered an iFi iDefender+. This should solve my ground loop problem as my DX3 Pro will no longer be getting the 5v from my computer, but from an external 5v power supply. If for some reason it doesn't. I may have to see if anyone wants to buy a DX3 Pro v2 to offset the DX7 Pro's exorbitant price tag...

 

[pacman]

After looking into USB isolators and ground loops, I did another test. I pulled an extension cable from another room whose outlets are on a different circuit breaker. When I did this, there was no buzzing. So, I ordered an iFi iDefender+. This should solve my ground loop problem as my DX3 Pro will no longer be getting the 5v from my computer, but from an external 5v power supply. If for some reason it doesn't. I may have to see if anyone wants to buy a DX3 Pro v2 to offset the DX7 Pro's exorbitant price tag...

Ground loops usually occurs when all devices are fed with same outlet or circuit, which is my case. Hope that your iFi solve your problem, let us know if it does.

 

[ZenTraveler]

Z390 Aorus Master motherboard

Have you tried using the yellow color port? The DAC-UP ports are supposed to be especially clean and free of noise/interference.

https://www.gigabyte.com/FileUpload/Product/2/6637/2018100517194938_src.png

 

[tdastrup]

Have you tried using the yellow color port? The DAC-UP ports are supposed to be especially clean and free of noise/interference.

https://www.gigabyte.com/FileUpload/Product/2/6637/2018100517194938_src.png

Yeah, I have. If you use the default function of those yellow ports, it's the exact same as a normal USB port. If you go into the BIOS, there is an option to disable USB power or provide up to 0.3v of extra power. If I disable USB power, the DX3 Pro doesn't think it's plugged into anything so it doesn't process the data signal from the computer, which sucks. I wish the DX3 Pro didn't require the 5v to sense that it was plugged in. That would be amazing.

 

[ZenTraveler]

it's the exact same as a normal USB port

Quote from Gigabyte:

GIGABYTE USB DAC-UP provides clean, noise-free power delivery to your Digital-to-Analog Converter. DACs can be sensitive to fluctuations in power from the other USB ports, which is why GIGABYTE USB DAC-UP takes advantage of an isolated power source that minimizes potential fluctuations and ensures the best audio experience possible.

https://www.gigabyte.com/mb/100-gaming/Audio

It have isolated power handling so that there isn't any extra dirty noise on the USB signal potentially interfering with USB DAC.
Maybe your motherboard or case have grounding issue.

 

[tdastrup]

It have isolated power handling so that there isn't any extra dirty noise on the USB signal potentially interfering with USB DAC.
Maybe your motherboard or case have grounding issue.

Interesting. I don't know exactly what they mean by "isolated power source" cause it's still using the same mains as the computer and the buzzing sounds just as bad when I'm plugged into the DAC-UP ports with power enabled on the port.

I got my iFi iDefender+ today. I'm plugging it into a DAC-UP port, which has power disabled on the port, and I'm providing the iDefender with 5v from a Samsung phone charger. Blissful silence. Problem solved.

 

[Veri]

I got my iFi iDefender+ today. I'm plugging it into a DAC-UP port, which has power disabled on the port, and I'm providing the iDefender with 5v from a Samsung phone charger. Blissful silence. Problem solved.

That's good to hear.

 

[bannani]

I have an dx3 pro V1, I am looking to have a decent output headphone for my hifiman HE4XX and Senheiser HD58X, or I am not satisfied with the output of this dx3pro.
Can you advise me for a good headphone amp for my dx3 , thanks.