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Topping DX7 Pro+ Review (DAC & HP Amp)

Rate this DAC & HP Amp

  • 1. Poor (headless panther)

    Votes: 7 2.2%
  • 2. Not terrible (postman panther)

    Votes: 8 2.5%
  • 3. Fine (happy panther

    Votes: 52 16.0%
  • 4. Great (golfing panther)

    Votes: 258 79.4%

  • Total voters
    325

amirm

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This is a review, detailed measurements and listening tests of Topping DX7 Pro+. It was sent to me by the company and costs US $699.
Topping DX3 Pro+ Stereo DAC Headphone Amplifier Review.jpg

As you see, the DX7 Pro+ sports the newer look of some Topping products. I did not care for it much before but it is growing on me. :) Three different headphone jacks are provided and all provide the same output, eliminating the need for adapters.
Topping DX3 Pro+ Stereo DAC Headphone Amplifier Back Panel Review.jpg

AC adapter is nicely built-in and we have the useful trigger input/outputs so that you can sequence power up of auxiliary gear.

Topping DX7 Pro+ DAC Measurements
Let's start with our usual dashboard using balanced out:
Topping DX3 Pro+ Stereo DAC Headphone Amplifier Measurements.png

Wow, for some reason I did not expect record breaking SINAD but we have it:
best stere dac review.png

A newer current to voltage converter may be behind this advancement.

RCA performance is nearly as good:
Topping DX3 Pro+ Stereo DAC Headphone Amplifier RCA Unbalanced Measurements.png


Dynamic range is of course superb:
Topping DX3 Pro+ Stereo DAC Headphone Amplifier Dynamic Range Measurements.png


As is distortion in both IMD and multitone:
Topping DX3 Pro+ Stereo DAC Headphone Amplifier IMD Measurements.png

Topping DX3 Pro+ Stereo DAC Headphone Amplifier Multitone Measurements.png


Jitter and noise is superbly low/unmeasurable:
Topping DX3 Pro+ Stereo DAC Headphone Amplifier Jitter Measurements.png


I don't think I have ever seen the 24-bit squarewave bits resolved as well as here on the left.

Linearity is perfect of course:
Topping DX3 Pro+ Stereo DAC Headphone Amplifier Linearity Measurements.png


The usual filter set is provided:
Topping DX3 Pro+ Stereo DAC Headphone Amplifier Filter Measurements.png


To make it easier to select one, here is the response up to cut off frequency:
Topping DX3 Pro+ Stereo DAC Headphone Amplifier Frequency Response Measurements.png


Filter 3 is the default and seems like the right choice (together with Filter 5).

Using those two optimal filters we get superb wideband performance vs frequency:
Topping DX3 Pro+ Stereo DAC Headphone Amplifier THD vs Frequency Measurements.png


This is impeccable performance for a DAC.

Topping DX7 Pro+ Headphone Amplifier Measurements
Let's start with our dynamic range for 50 mv output:

Topping DX3 Pro+ Stereo DAC Headphone Amplifier 50 mv Measurements.png

This is great but not chart topping:
best headphone amplifier review.png


Power is just about everything so let's look at that at 300 ohm:
Topping DX3 Pro+ Stereo DAC Headphone Amplifier Power 300 Measurements.png


This is plenty to drive high impedance headphones. I like that it doesn't clip so if you hear any distortion, it is your headphone doing it, not the amplifier!

Switching to current limited 32 ohm, we get:
Topping DX3 Pro+ Stereo DAC Headphone Amplifier Power 32 Measurements.png


This is lots of power as well combined with exceptionally low noise and distortion especially in low gain mode.

Finally, here is our sweeps at different impedances:
Topping DX3 Pro+ Stereo DAC Headphone Amplifier Power vs impedance Measurements.png


Remember that Power = Volt * Volt/impedance. So you can determine how many watts you have at any of the above impedances before clipping.

Topping DX7 Pro+ Headphone Listening Tests
I started to listen with my everyday and difficult to drive Dan Clark Stealth headphone. There was plenty of volume to get these cans going. I could get the amp to distort on one track from -3 dB to 0 dB but that was not a volume I could tolerate in normal listening. Sound was beautiful, detailed with a quiet background allowing me to hear deep into the recordings.

Switching to Sennheiser HD650 provided a superb experience as well. There was so much power available that I could go beyond any reasonable listening level. Fidelity was exceptional. So much so that I did not want to put them down and take picture of the unit for the review!

Conclusions
We expect the best from Topping and yet, they still manage to surprise in how well they execute. To create a DAC to break their own records requires a level of self motivation for excellence that few companies attempt. The performance of DX7 Pro+ is just stunning in this regard with no fault to identify whatsoever.

The headphone amplifier is also quite a performer albeit with a target just shy of stand-alone amps from Topping. Superb experience is to be had with the combination leaving nothing to complain about.

It is my pleasure to recommend Topping DX7 Pro+. The product personifies dedication to excellence in engineering and design.

------------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 

oscar_dziki

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wow. Great product. @amirm I have 2 questions that were bugging me.
1. Why is 50 mV test done with 600 Ohm load if what we try to find there is a noise in iems. Shouldn't it be done with sth. like 16 ohms?
2. If it's best for the listening test to use a single driver, shouldn't it be the same for headphones? :D
 
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Rja4000

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Nice review :cool:
Thanks

4.156V level is 0.33dB more than 4V, so this probably partly explains why you go over 123dB SINAD ;-)
Is that the max output level ?
 
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amirm

amirm

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wow. Great product. @amirm I have 2 questions that were bugging me.
1. Why is 50 mV test done with 600 Ohm load if what we try to find there is a noise in iems. Shouldn't it be done with sth. like 16 ohms?
It won't make a difference. I am just putting some load on it as opposed to none.
 

Χ Ξ Σ

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The wider chassis looks much better than the DX5. I am hoping for an even wider model in the pipeline.
 
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amirm

amirm

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Here's the max output power vs load for every Topping AIO currently sold:
View attachment 228156
Note that I used WolfX-700's data, because he does high res sweeps at four different loads.
Wow, that is super nice and useful! Would be great to post these graphs in every review if you have time.
 
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amirm

amirm

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4.156V level is 0.33dB more than 4V, so this probably partly explains why you go over 123dB SINAD ;-)
Is that the max output level ?
It is. I allow that little bit of cheating in every DAC I test. If it goes well over that, then I adjust down.

And yes, that is max output.
 

respice finem

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Golfing strikes again :)
OK, not really cheap, but in the so called high end audio "spheres", it's usuall to pay such (and higher) prices for a DAC, or preamp, or HP amp alone.
 

staticV3

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Wow, that is super nice and useful! Would be great to post these graphs in every review if you have time.
Thanks!
The thing is I need four or more data points to do reliable curve fitting and extrapolation.
Your THD+N vs Vrms sweeps are very coarsely stepped and don't give me reliable results.
And the THD+N vs Power sweeps are only at 33 and 300Ω.
I could only make this graph because Wolf has measured these DAC+Amps before, including hi res THD+N sweeps at 16, 32, 68, 300Ω, like this:
1661192654-THDN-Ratio-vs-Measured-Level.jpg

Were you to adopt this method, then I could post that graph for every review.
Otherwise I'll have to see if a review of the same DUT exists on L7Audiolab as well.
 
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oscar_dziki

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It won't make a difference. I am just putting some load on it as opposed to none.
Thanks for your response. How about my second question?
2. If it's best for the listening test of speakers to use a single driver, shouldn't it be the same for headphones? :D
 

Mulder

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Is it possible to somehow measure how sensitive the SPDIF input is to jitter? Some previous Topping DACs have not worked with CD/DVD players, i.e. they have not been able to lock the incoming signal properly.
 
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amirm

amirm

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The thing is I need four or more data points to do reliable curve fitting and extrapolation.
I can export the data so you don't have to do the curve fitting.
 
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amirm

amirm

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Is it possible to somehow measure how sensitive the SPDIF input is to jitter?
I tried but no matter how much jitter I inserted (up to the limit of AP), the DACs would capture it without problem. I need to measure a problematic source to see what it is spitting out. And then maybe use that as the corner case.
 
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amirm

amirm

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Adding on, I don't think jitter is the problem but rather, the actual clock rate of data. Audio slaved to video could deviate a lot from nominal sample rate.
 

staticV3

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Is it possible to somehow measure how sensitive the SPDIF input is to jitter?
Yes that's possible, but I'm not sure if jitter is the whole story.
Because on one hand you have (presumably) jitter related issues like LG OLED TVs cutting out audio for a split second every few minutes via Toslink, on the other hand you have what seems like fundamental incompatibilities between devices, like some of Topping's DACs and CD players. I imagine if it were just excessive jitter, then the DAC would output at least some signal, albeit a broken one.
Please someone correct me here if I'm off the track.

Here's how you can test for jitter resistance with the APx555:
TPJLV8KTY3SFVBA6.jpg
 

cheapmessiah

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Looks and performs really nice.

Kind of low power at 32 ohm, I would like to see at least 3W at that load for hifiman aryas and EDXSs eqed to Harman, and DCAs Aeons, considering the price devices like this should, in my opinion, aim to power those kind of planar headphones that might be what a potential buyer of this price bracket be looking into too.
 
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