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Review and Measurements of Topping DX3Pro DAC and Headphone Amp

Roen

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Suppose that the DAC is operating in a fully warmed, steady state. Do you agree that the internal air temperature does not change unless the case or ambient conditions are altered?
If you’re assuming thermal equilibrium with your initial condition, then absent any conditions that remove said equilibrium, guess what, thermal equilibrium still exists.

But that’s a tautology and only applies in a specific set of circumstances, of which you’ve assumed, and may not necessarily hold.
 

yue

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@HammerSandwich is correct if the heat sink is efficient enough. if it is fully warmed and gets into a steady state, the temperature won't change. new heat generated will match the heat loss into the air. but that is based on the condition that the heat sink is efficient enough.

One can take the temperature of a real device operating at full power to see if the temperature reaches a steady state and won't get higher through time.

The experiment set up is simple --- ask someone who has the device and a IR thermometer. Operate the device with full power, and take temperature of each chip through time until it doesn't change anymore. if it's below 80C we can safely say the device is safe.
 
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Either way, I am not getting the dx3 pro, mx3 seems more reliable and stable
Yeah, because no one uses it.
I'm not sure if you realize it but you are comparing unit that was incredibly hyped and bought by lots of people with something that probably no one here has. There is actually little failures of dx3 so far compared to overall volume.
If you want reliable product, buy something by jds labs for instance.
 
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If you’re assuming thermal equilibrium with your initial condition, then absent any conditions that remove said equilibrium, guess what, thermal equilibrium still exists.
I agree. Same power input + same chassis & venting = same internal temps.

Step 2, then, is what happens to a given component's temperature when its power consumption & surrounding air temp don't change but a heatsink is added? The chip runs cooler, because it can pass heat to the air more efficiently.

But that’s a tautology and only applies in a specific set of circumstances, of which you’ve assumed, and may not necessarily hold.
Sure, but this needed to be spelled out step by step.

Final note: the heatsink's mass will keep the chip running at a more constant temp when the power input does vary.
 
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Yeah, because no one uses it.
I'm not sure if you realize it but you are comparing unit that was incredibly hyped and bought by lots of people with something that probably no one here has. There is actually little failures of dx3 so far compared to overall volume.
If you want reliable product, buy something by jds labs for instance.
That and the mx3 is almost $100 cheaper and considering the state of the Canadian dollar, the mx3 fits my budget better so I can get a decent pair of speakers so I don't have to use headphones all the time
 

yue

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"If" seems to be the key word here :)
All I proposed is to design an experiment to answer people's doubt. This experiment is very easy to do --- @amirm can do it with a $10 IR thermometer (most likely he already has one) and takes probably ~30 min waiting time for it to heat up (by shortening the headphone output with a 30Ohm resistor), and can get into a conclusion (either it can or cannot reach a steady state with < 80C surface temperature) very easily.
 

yue

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If I'm not mistaken, this is Topping's first amp with low output impedance. If it's truly <0.1 Ohms, that doesn't give a lot of margin for protection of the discrete output stage from itself. Perhaps someone can post a thermal image of the PCA in that area?

View attachment 20220
View attachment 20221
you are focusing on an entirely wrong area. the chip there is 54331 which is a volume step down converter (i.e., DX3Pro's digital volume control). It's a low power device and the datasheet does not even require heatsink for this chip.
the white solid stuff before the headphone jack is a relay to turn on/off the headphone output.
 

amirm

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All I proposed is to design an experiment to answer people's doubt. This experiment is very easy to do --- @amirm can do it with a $10 IR thermometer (most likely he already has one) and takes probably ~30 min waiting time for it to heat up (by shortening the headphone output with a 30Ohm resistor), and can get into a conclusion (either it can or cannot reach a steady state with < 80C surface temperature) very easily.
Let me see if I can free up some time tonight for a thermal study...
 

yue

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I took a look at the circuit board on their website.
The most powered component should be the OPA1612, OPA1640 and 2sd669ac (transistor in the diagram).
They together form the amplification stage of this device.
I read their respective datasheet.
OPA1612 and OPA1640 could operate at 125C (257F) safely.
2sd669ac can even operate at 150C (302F) safely.
Other ICs (such as the AKM chip or the XMOS chip) can operate at 85C.

I would say these are pretty wide temperature range. I would be surprised if it can even get that hot at the max power.
 
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Yeah, because no one uses it.
I'm not sure if you realize it but you are comparing unit that was incredibly hyped and bought by lots of people with something that probably no one here has. There is actually little failures of dx3 so far compared to overall volume.
If you want reliable product, buy something by jds labs for instance.
I agree on this and ive been affected by a faulty unit
 
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It might be placebo or just dumb, but ive been not using the dx3 for a day because i have planned to return it and got it packed (controller not worrking), since Paypal is taking time to give me the instructions to send it back i decided to unpack it and use it meanwhile. I used my own power supply [email protected] because I didnt want to unroll the stock one and well, the bass i feel like improved a fucking lot. Maybe its placebo of my ears not using it for a day, or maybe im right and it actually improves quite a bit. Sennheiser HD580 here, from lacking some bass and lots of sub-bass to having fine bass and some sub-bass

I know the lacking are on the headphone side, but still i wanted to talk about the improvement i felt the power supply did.
 

Toku

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Either way, I am not getting the dx3 pro, mx3 seems more reliable and stable
It is useless argument!
That is MX 3 is simply the type of your choice.
It is not a target product to be discussed in the same table as DX 3 Pro.
MX3 also has some problems.

DX3 Pro is never a perfect product, but it is a wonderful product.
I feedback the problem found to Topping and feel the pleasure as a user to make it a more wonderful product.
 
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Apologies in advance if I rub anyone the wrong way, but I can't hold my tongue...

I really love the DIY and hobbyist streak displayed around here and can personally relate to it. OTOH, I'm struck by the irony of us discussing thermal imaging, DIY heatsinks and custom fan installation to fix problems with the "highly recommended" DX3 when we continue to rag on Schiit for their build quality. To be clear, I personally had my first Magni 3 die on me within 15 minutes of first plugging it in, so I'm not claiming that Schiit makes great quality stuff.

I think it's important to call a spade a spade, and the anecdotal reports I'm reading on here make me want to stay away from the DX3, in particular because sending it to China for warranty service is such a hassle. Yeah it has a ton of features, but I suspect a lot of people don't really need those and might be better off with a simpler DAC (even one from Topping) paired with a JDS Labs Atom and just be done with it.
It's also important to consider that there are a lot of users who are satisfied with this product that do not feel the need to be vocal about it, as opposed to others who have experience issues.

(With that said, I've probably cursed myself, and will be back to complain in a few weeks.)
 
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I did again the firmware upgrade and scanned the Bluetooth devices without any chance . I'll contact Audiophonics
Got my unit today and was having the same issue. I could not pair it with any BT device I have. Tried the factory reset, no change. Then I reinstalled the latest firmware and now it works.
 
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Love my DX3 Pro but the very brief instructions don't address the settings for a volume controlled DAC output into a conventional amp. Can this be done and if so how?
 
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Love my DX3 Pro but the very brief instructions don't address the settings for a volume controlled DAC output into a conventional amp. Can this be done and if so how?
Press "Line Out" button on remote or click rapidly twice unity's button until it shows "DAC" and volume on display. Be carefull, if you press twice one more time or press "Line Out" on remote twice it'll change to fixed 0db output.

When the display shows "DAC" and volume, it's on "pre-amp" mode with volume control. It's the first DAC mode. When shows frequency, it's on fixed 0db mode, which is second.

If you don't want to deal with these DAC modes, you can choose the blinking headphone mode which outputs both 3.5mm and RCA with volume control. With the remote, just press the center button in the middle of round volume and arrows button.
 
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Got my unit today and was having the same issue. I could not pair it with any BT device I have. Tried the factory reset, no change. Then I reinstalled the latest firmware and now it works.
Lucky you! I'm waiting for Audiophonics to know if they accept to send me a new unit (but tested by them before sending) or accept their offer of partial refund.
 
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It's also important to consider that there are a lot of users who are satisfied with this product that do not feel the need to be vocal about it, as opposed to others who have experience issues.

(With that said, I've probably cursed myself, and will be back to complain in a few weeks.)
Agreed, it is virtually always the case that dissatisfaction results in more airtime than satisfaction; having said that if there is considerable vocalization of dissatisfaction with a new product there likely are some issues to be resolved (hopefully in FW/drivers, in a V2 of the product if not amenable to SW fix).

As to me, so far having a lot of fun with my DX3Pro listening from Tidal. It shares ear time (USB and Bluetooth) with my DX7S/MD-THX 789 and D50/Atom stacks (both through USB) and subjectively holds its own rather well. So far no reliability issues. Clicks only when changing sample rates, and since I am listening to my headphones when this happens the only one that might be bothered is the dog.

Chalk me up as one of the “silent majority”.
 
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