Topping DX7 Pro+ Review (DAC & HP Amp)

[Billy Budapest]

You measured the need for 2W?

I just stop questioning when people say their headphones need 1W. They obviously listen at very high volume levels. As I have gotten older (I turned 50 early this year, which granted isn’t really THAT old), I have found that I need to turn the volume up too, but never to the levels these folks are talking about.

 

[Marc v E]

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.

I think you're right. I have a dx7pro that has been performing flawlessly except when I connected it to a spif output from a panasonic bluray and watched a movie. It lost signal quite a few times. Notably during quiet passages. The movie I watched was First Man. I will try it some more to see what I can find.

 

[Lorenzo74]

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.
View attachment 228132
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.
View attachment 228133
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:
View attachment 228134
Wow, for some reason I did not expect record breaking SINAD but we have it:
View attachment 228135
A newer current to voltage converter may be behind this advancement.

RCA performance is nearly as good:
View attachment 228136

Dynamic range is of course superb:
View attachment 228137

As is distortion in both IMD and multitone:
View attachment 228138
View attachment 228139

Jitter and noise is superbly low/unmeasurable:
View attachment 228140

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:
View attachment 228141

The usual filter set is provided:
View attachment 228142

To make it easier to select one, here is the response up to cut off frequency:
View attachment 228143

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:
View attachment 228144

This is impeccable performance for a DAC.

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

View attachment 228146
This is great but not chart topping:
View attachment 228147

Power is just about everything so let's look at that at 300 ohm:
View attachment 228148

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:
View attachment 228149

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:
View attachment 228150

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.

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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/

“The product personifies dedication to excellence in engineering and design.”

Well said Amir

 

[NMixes]

A used RME for $700 is still a better value than this for $450.

why?

 

[gvl]

That seems to be an entirely subjective judgment, but okay.

Certainly not based on SINAD but the RME has so much more useful features than this, not to mention better customer support.

 

[Prince Valiant]

Certainly not based on SINAD but the RME has so much more useful features than this, not to mention better customer support.

That's also now versus waiting an unknown number of months.

 

[SuicideSquid]

Certainly not based on SINAD but the RME has so much more useful features than this, not to mention better customer support.

The question isn't whether the RME has some advantages over the Topping, the question is whether those advantages are worth paying almost twice as much for. That's a subjective value judgment. For you it clearly is. For me, I'm not so sure.

 

[J Ratcliffe]

A used RME for $700 is still a better value than this for $450.

You're smoking crack. Stop.

 

[formdissolve]

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:
View attachment 228159

Glad I'm not the only one that noticed the LG OLED optical port issue. I can barely watch using my E50, so I had to switch back to my old Schiit modi 3 and it works 99.9% of the time without any SPDIF issues.

 

[Bamyasi]

I do not get it. The documentation says it has "step volume control" but also calls it "encoder". Is this digital encoder or analog step volume control? Or maybe both, depending on the output mode, e.g. pre-amp is digital but phone amp is analog? @amirm Can you please clarify?

 

[Music1969]

Isn't the price very similar to the A90D though?

We were talking about low impedances though?

As I wrote, SP400 good to 12 ohms

 

[juliangst]

We were talking about low impedances though?

As I wrote, SP400 good to 12 ohms

Any reason to get it over the A90D? SP400 is more expensive

 

[Kosta]

Certainly not based on SINAD but the RME has so much more useful features than this, not to mention better customer support.

RME proababy not a good comparison , but you have good point , there comes a time whe you question chasing the numbers , I can get almost as much perfromance with a smsl c200, , dx5 and even the g5 so why would anyone pay hundeds more for this.

 

[Music1969]

Any reason to get it over the A90D? SP400 is more expensive

Yes reasons are in my 2 posts

 

[amirm]

I do not get it. The documentation says it has "step volume control" but also calls it "encoder". Is this digital encoder or analog step volume control? Or maybe both, depending on the output mode, e.g. pre-amp is digital but phone amp is analog? @amirm Can you please clarify?

It is an encoder which programs the DAC chip. I agree the marketing language is confusing.

 

[Jimster480]

A used RME for $700 is still a better value than this for $450.

That depends on why you would consider it to be better. I can't imagine they have sold so many of these Army units that everyone could just buy a used one. Likely there are a few for sale around in the market and if people chose to buy it they would all be gone in a single day and that would be it.

 

[Jimster480]

I just stop questioning when people say their headphones need 1W. They obviously listen at very high volume levels. As I have gotten older (I turned 50 early this year, which granted isn’t really THAT old), I have found that I need to turn the volume up too, but never to the levels these folks are talking about.

Yeah I mean I have literally four heavy planar headphones and even my Geshelli Archel2 can power them all.... I prefer my THX789 for its dual headphone out as it helps me to compare headphones and switch easily. However I haven't found any headphone that needs high gain with any movement of the volume knob towards the right.
The Archel2 I can get close to maxing out, but I haven't ever and that really depends on the headphone obviously.

 

[gvl]

That depends on why you would consider it to be better. I can't imagine they have sold so many of these Army units that everyone could just buy a used one. Likely there are a few for sale around in the market and if people chose to buy it they would all be gone in a single day and that would be it.

They are there nonetheless, I managed to get 2 and they were hardly the last ones they are better for headphone use due to the built in EQ.

 

[tomchris]

Am I mistaken, or does this model rival the Mola Mola Tambaqui ($13,400) in terms of SNR of ~130 dB and perhaps other measures as well?

It would really be something having Topping surpassing Mola Mola Tambaqui.

 

[sam_adams]

A big Thank You! to @JohnYang1997 and the Topping team for your attention to this: