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Review and Measurements of Topping DX3Pro DAC and Headphone Amp

jani80k

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He’s plugging in IEMs (BA or hybrid DD+BA) which will have more bass emphasis as the output impedance of headphone amp goes to zero or as damping factor increases. My Campfire Andromeda is an extreme version of this where a minute change in the output impedance can make it sound totally recessed in bass. Heck it’s the only IEM that I can differentiate the sound from different DAPs and dongles due to sensitivity to the headphone jack’s output impedance. Interesting that OTL tube amps paired to 300 ohm headphones have opposite effect where the higher output impedance provide more bass emphasis to those headphones.
Whats the output impedance of the V2?
 

majingotan

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jani80k

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Yuno

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Ok, sending this back to Amazon. 10 ohms is a lot. If that affects even my 150 ohms sennheisers.. what will it not affect? 300 ohms headphones should be affected even...
10Ohm output impedance will not affect how 150Ohm impedance headphones will sound, and will frankly not affect majority of low impedance headphones in audible terms. Your dx3 is either broken, setup incorrectly in some way or you are running on some heavy placebo fuel.
Pick whichever one you want.
 

jani80k

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@amirm would it make sense to put a Warning as "Update 4" on the first page? People like me are reading the review and buying the dacamp because they're thinking the V2 is an improved version.
 

jani80k

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10Ohm output impedance will not affect how 150Ohm impedance headphones will sound, and will frankly not affect majority of low impedance headphones in audible terms. Your dx3 is either broken, setup incorrectly in some way or you are running on some heavy placebo fuel.
Pick whichever one you want.
Maybe the slight lack of bass on the 150 ohms is due to AK vs ESS. But the SMSL M500 has clearly more bass to it over the DX3 Pro whereas the latter has clear more separated rendition.
 

majingotan

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Maybe the slight lack of bass on the 150 ohms is due to AK vs ESS. But the SMSL M500 has clearly more bass to it over the DX3 Pro whereas the latter has clear more separated rendition.

Has nothing to do with the DAC chip, just pure output impedance effect to frequency response. Try FiiO BTR5 with ESS chip and that should pump more bass on low impedance IEMs based on its output impedance compared to DX3 V2
 

jani80k

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Has nothing to do with the DAC chip, just pure output impedance effect to frequency response. Try FiiO BTR5 with ESS chip and that should pump more bass on low impedance IEMs based on its output impedance compared to DX3 V2
I got the DX3 Pro for my IEMs at work because I read on some thread that it is (was) Amir's daily driver. I have been reading a lot about Dac/Amps in the past and I studied many measurements/reviews on this site. If I woul have known that the output impedance of the V2 is 10 ohms, I would not even have considered buying it. Fortunately, I can send it back via Amazon Prime. What would be a good alternative to this then? FiiO BTR5 sounds interesting but so far only Zeos has reviewed it and there aren't any measurements out, yet. Is there another clean sounding dacamp with low output impedance?
 

MattH5

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I got the DX3 Pro for my IEMs at work because I read on some thread that it is (was) Amir's daily driver. I have been reading a lot about Dac/Amps in the past and I studied many measurements/reviews on this site. If I woul have known that the output impedance of the V2 is 10 ohms, I would not even have considered buying it. Fortunately, I can send it back via Amazon Prime. What would be a good alternative to this then? FiiO BTR5 sounds interesting but so far only Zeos has reviewed it and there aren't any measurements out, yet. Is there another clean sounding dacamp with low output impedance?
The JDS Labs Element 2 sounds like a good option... but it's twice the price. Maybe get a decent cheap DAC and a JDS Labs Atom, that'll be cheaper.
 

jani80k

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I will wait for the E1DA 9038D.
 

jani80k

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Are you using USB on the dx3?
Yes. I have sent the DX3 back already. It has an output impedance of 10 ohms which is ridiculously bad. I would have never considered the device had I known this. This output impedance seems to be the reason why the bass is missing on my TIN T2 IEMs. This is not the case on my SMSL M500 - my IEMs are fine on that device.
 

ZenTraveler

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Hi ASRs!
Long time reader first time poster here.

I'm really interested on this topic of output impedance. I have a V2 which I enjoy using it as DAC for my active speaker and also as headphone amp for my headphones. The output impedance never bothered me before as most of the time I'm using planar headphones. Since the recent discussion on how output impedance alter the sound I want to explore more on this rabbit hole.

I fortunately also have Tin T2 to test. I use it to compare between DX3 Pro and NX4DSD, which have very low output impedance. I don't have equipment to do volume matching so it was manually adjusted as best as my ear allow me to. After listening to numerous songs, especially on bass heavy genre, try as I might but still I could not hear any difference between the 2 devices. Dissatisfied, I try my dynamic driver headphone which is 35 ohm impedance, still can't hear any difference. Why is it so?

I been reading more on output impedance and that lead to damping factor. Some of the most famous article on this topic I believe will be from Stereophile, NwAvGuy and Inner Fidelity. They showed increase of 6 dB or even 12 dB in some frequency response, but those are when the output impedance are much higher than the headphone impedance, and I think at maximum volume level? How much difference if it were only at normal listening level? Usually I'm listening at around -30dB, low gain.

I think NwAvGuy is the one that popularized the idea of 1/8th of impedance, or 8 damping factor. Basically it means headphone impedance must be higher by 8 times from amp's output impedance, if headphone impedance is 35 ohm then amp output impedance can't be higher than 4.375 ohm. But why in his article Sennheiser HD590 which is 120 ohm impedance paired to 10 ohm output amp still increase 1 dB above 20 hz? Is he meaning 12 damping factor is still not enough?

Inner Fidelity article is interesting as Dr. Jan Meier show AKG K420 which is 32 ohm give zero oscillations when the output impedance is 88 ohm while Tyll show HD800 getting bass bumped when output impedance change from 0 to 100 and 200 ohm. When output impedance is 100 ohm, that is only 3 damping factor, we're seeing bump up about 1.25 dB. For 200 ohm which is 1.5 damping factor, we're seeing bump up about 3 dB. Again, such increase in dB is only on max volume level? If in lower level then the bump in dB will be smaller? And why Dr. Jan Meier result and Tyll are the opposite of one another?

I found this post from head-hi when searching about this topic. The headphone is 250 ohm while the amp output impedance is 10.3 ohm (which give 24 damping factor), and he also use serial resistors to bump up the output impedance to 100 ohm (which give only 2.5 damping factor). In both test the headphone still produce almost the same frequency response, there's only very small bump in some part of the frequency because of low damping factor. Are damping factor does not need to be as high as 8 if measured from headphone response?
 

Androxylo

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Today I compared the phone exit of my dx3Pro and the "preamp" RCA exit. In both cases I fed the output directly into mine Schiit Aegir, in both cases used internal volume control. USB from Linux with all necessary 'pulseaudio' tunups & upsampling.

The difference is huge, just huge, I was amazed how much the same device can differ. So my suggestion is - do not use phone exit of dx3pro, fetch a separate $100-$150 head amp and connect it via RCA.

And btw yes, RCA preamp mode to Aegir is a perfect sound. I don't think anything could be upgraded here.
 

patient_ot

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Need a bit help here. BT was working fine for me about two weeks ago...I don't use it often but tried to use it today and can't get it to pair/connect with my phone. Deleted from available devices on my phone and now the phone can't detect the device in a BT search. Any tips to fix this? Like I said, was working fine a couple weeks ago.
 

Androxylo

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I've tried to replace the headphone output of my dx3pro with external headamp connected through RCA output. It's much, much better. You can get better sound from Topping this way. (also see my post #4,645 above)
 

jani80k

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In Germany the dx3 pro is 219 shipped. If I would spend an additional 100-150 on an extra amp, I might as well get a SMSL M500 - which is what I did ;)
 

patient_ot

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Was able to get BT on the DX3 working again by doing a hard reset on the device a couple times, unplugging it, and resetting my phone's network settings a couple times and rebooting the phone. For the future I would like to see Topping implement a pin code system for this device. I think a neighbor may have inadvertently connected to my DX3.
 

Gray

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Was able to get BT on the DX3 working again by doing a hard reset on the device a couple times, unplugging it, and resetting my phone's network settings a couple times and rebooting the phone. For the future I would like to see Topping implement a pin code system for this device. I think a neighbor may have inadvertently connected to my DX3.

True, even a simple "0000" would've been better than this. I got the DX3v2 and had my neighbour streaming some music on my device. :D
I didn't even know the signal could go so far, 8-9 meter and 2 external brick walls.
 
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Hey to all , I’m looking for almost new desktop dac/amp
Now i found this and see some people problems and scared for buy !!
What is problems?
i need someone help , what is V2 ,1905xxxx or 1904xxxx or.... ???!!! What is a good version ?
Can i buy it ? or another brand is better than this at same price (k5 pro)
 
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