• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). Come here to have fun, be ready to be teased and not take online life too seriously. We now measure and review equipment for free! Click here for details.

Topping DX7 Pro DAC and Headphone Amp Reviewed

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
27,422
Likes
66,789
Location
Seattle Area
#1
This is a review and detailed measurements of the new Topping DX7 Pro DAC and headphone amplifier. It was kindly sent to me by the company. The DX7 Pro costs US $599 but they usually go on sale for less on sites such as drop.com.

The DX7 Pro has the most refined look of any Topping produce with the curved machine front giving it an elegant look:

Topping DX7 Pro Balanced DAC and Headphone Amplifier Review.jpg

There are small touches such as beveled volume control edge which helps you grab it there and quickly jog it to the volume you want. The wheel is very responsive allowing you swiftly change volume despite its wide range of 0 to -99 dB.

The same remote that powers the rest of Topping line is included. Indeed I used my Topping DX3 Pro remote to control it.

The back panel shows high quality connectors and construction:

Topping DX7 Pro Balanced DAC and Headphone Amplifier Back Panel Review.jpg

Bluetooth seems to have become a standard feature now in Topping product (I did not get a chance to test it though). In my book any DAC over a few hundred dollars should have balanced XLR outputs which the DX7 Pro has.

The inclusion of AC mains power supply means no dongle hanging from the unit.

Overall, the mechanical look and feel is very solid and unit easy to operate with the remote.

While Topping provides drivers, I used the Windows 10 class drivers with no issues.

DAC Audio Measurements
As usual, we start with our dashboard while feeding the unit via USB and measuring what comes out of XLR output:
Topping DX7 Pro Balanced DAC and Headphone Amplifier Audio Measurements.png


Great to see 4 volt output right on the money. But even greater is the incredibly low distortion spikes that are clocking at less than -132 dB or so! SINAD is the amplitude of our 1 kHz tone relative to both noise and distortion. It is translating into 119 dB which means it is the noise that sets that, not distortion. With best case threshold of our hearing being -116 dB, there just isn't any audible noise or distortion here.

The noise is however a bit higher than our best in DAC ever, placing the DX7 Pro just a hair below the peak:
Audio DACs Measured 2019.png


The DAC above it costs almost twice as much so this is a great accomplishment.

Back to noise, here is our dynamic range:

Topping DX7 Pro Balanced DAC and Headphone Amplifier Dynamic Range Audio Measurements.png


This is an excellent number although about 5 dB worse than our best of the best.

Jitter test shows some inconsequential mains related noise spikes:
Topping DX7 Pro Balanced DAC and Headphone Amplifier Jitter Audio Measurements.png


Intermodulation+noise shows the slightest hint of famous ESS DAC IMD Hump where distortion rises at mid levels. Topping has done a great job of suppressing this:

Topping DX7 Pro Balanced DAC and Headphone Amplifier IMD Audio Measurements.png


As a result the DX7 Pro essentially outperforms its smaller brother, DX3 Pro in the entire range.

Linearity shows perfection in one channel but slightest deviation in the other:
Topping DX7 Pro Balanced DAC and Headphone Amplifier Linearity Audio Measurements.png


My cutoff is 0.5 dB so we can still consider the DX7 Pro resolving the full 120 dB which translates into 20 bits of accuracy.

Simulating "music" using 32 tones shows us very low levels of intermodulation distortion:

Topping DX7 Pro Balanced DAC and Headphone Amplifier Multitone Audio Measurements.png


High frequency tones do generate ultrasonic tones which thankfully we don't hear but impacts THD+N versus frequency:

Topping DX7 Pro Balanced DAC and Headphone Amplifier THD vs frequency Audio Measurements.png


Edit: forgot to include the filter response in the original review:
Topping DX7 Pro Balanced DAC and Headphone Amplifier Filter Audio Measurements.png


Headphone Amplifier Measurements
Measuring noise when the unit is outputting very little voltage (50 millivolts) gives us very good but not great results:
Topping DX7 Pro Balanced DAC and Headphone Amplifier 50 mv dynamic range Audio Measurements.png

Most quiet headphone amplifiers.png


The gain setting I suspect is just a digital attenuation so doesn't get a chance to reduce the noise level like an analog control in a dedicated headphone amplifier could.

Power into 300 ohm using 1/4 passes my 100 milliwatt requirement meaning it can easily power high impedance headphones to super loud levels:

Topping DX7 Pro Balanced DAC and Headphone Amplifier Power into 300 ohm Audio Measurements.png


I only plotted the more noisy channel as inclusion of the other made the graph hard to read. The omitted one was better performing. Basically we have the same performance as the DX3 Pro but with reduced distortion at the highest volume.

Switching to the other extreme and testing with a 33 ohm load emphasizing current delivery we get:
Topping DX7 Pro Balanced DAC and Headphone Amplifier Power into 33 ohm Audio Measurements.png


Here the noise level was higher but again, distortion was lower at the extreme compared to DX3 Pro.

Switching to 50 Ohm load and measuring both 1/4 and XLR balanced output shows that the latter produces more power:
Topping DX7 Pro Balanced DAC and Headphone Amplifier Power into 50 ohm Audio Measurements.png


At 1.6 watts, the XLR output easily clears my 1 watt hurdle for power needed to drive low impedance headphones well. And we also get lower noise to boot.

Channel balance shows perfection due to digital level control in the DAC:
Topping DX7 Pro Balanced DAC and Headphone Amplifier Channel Balance Audio Measurements.png


Which is a great advantage of these DAC+Headphone amplifiers over most dedicated amplifiers.

Output impedance is a bit high though:
Headphone Amplifier Impedance Measurements.png


If your headphone has an impedance curve that is a) less than 60 ohm and b) is not flat, then its frequency (for better or worse) may change a bit.

Headphone Listening Tests
I started with my very low impedance (25 ohm) closed back Drop Mrspeakers Ether CX using XLR "balanced" headphone output. In high gain the DX7 Pro had no trouble pushing these headphones to skull resonating level. :D These are tough to drive headphones but despite that, there was no issue whatsoever in driving them to get maximum bass punch, detail and fidelity.

Next up was the Sennheiser HD-650 which the DX7 Pro drove with fantastic dynamic range, detail and performance. You just listen for a few seconds to know that the amp is both transparent and the boss. :)

So subjectively, there is no concern whatsoever in driving such low and high impedance headphones to very high, ear damaging levels.

Conclusions
The Topping DX7 Pro betters the DAC performance of all the produces Topping had produced. On SINAD measurement, it lands in the coveted range of near 120 dB, proving beyond a shadow of doubt that it is transparent to any content you attempt to play. This is a super challenging bar to reach and I congratulate Topping for getting there.

The headphone is a step below state-of-the-art from measurement point of view. Subjectively however, it is very powerful and clean and satisfies every need I personally have. Some of you know that I use a Topping DX3 Pro as my everyday DAC and headphone unit. Given the performance of the DX7 Pro, looks and usability, I am going to replace that with DX7 Pro.

Needless to say, I am happy to give my recommendation to Topping DX7 Pro.

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

It was bound to happen: the panthers have unionized and now demanding raises through collective bargaining. They are threatening a walk-out leaving me with no panthers for product reviews. In other words, they have me by the neck. So, please donate generously to keep them modeling for us using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 
Last edited:

VintageFlanker

Major Contributor
Forum Donor
Joined
Sep 20, 2018
Messages
1,504
Likes
3,062
Location
Paris
#2
Thanks, @amirm

Exceptional performance for the price.

I'm shocked how some companies managed to offer such increasing value these last two years... SOTA headamps for $150-400, SOTA DACs for $500...Are we entering in a new golden age?

You will need to upgrade your AP soon! ;)

Ps: can't wait to see if the M500 performs that well for 200$ less!
 
Last edited:

GrimSurfer

Major Contributor
Joined
May 25, 2019
Messages
1,238
Likes
1,376
#3
Superb performance from the DAC section. The channel differences are small. Is it possible that this lies within production tolerances?

In general, however, one certainly doesn't need more than this in the D-->A domain.
 

MediumRare

Addicted to Fun and Learning
Forum Donor
Joined
Sep 17, 2019
Messages
949
Likes
995
Location
Chicago
#4
Help please: I have LCD-3 headphones. I understand they have about 58 ohm impedance, flat across the full frequency range (https://www.innerfidelity.com/images/AudezeLCD3Rev2sn2613375circa2012.pdf). I'm trying to decide on the DX7 Pro or use a D50s DAC + Monolith THX 887 for the amp. Advice, please?

Edit: I seem to have used an out of date set of measures as my phones are the Fazor version with higher impedance, about 117. So, any advice interpreting this would be most welcome: https://www.innerfidelity.com/images/AudezeLCD3Fazorsn2715432.pdf
 
Last edited:

LLL

Member
Forum Donor
Joined
Aug 9, 2019
Messages
50
Likes
111
Location
Seattle, WA
#6
Great engineering out of Topping once again. I can't imagine how many of the major manufacturers are now making an attempt to hire some of Topping's people away.

Come to think of it, I guess they are not; since they seem to care more about marketing. :)
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
27,422
Likes
66,789
Location
Seattle Area
Thread Starter #7
You will need to upgrade your AP soon! ;)
Well, on that front, there is no hope. There is the "Rev B" version of my analyzer and companies that have it tell me it is no better than my current unit.

Fortunately I can keep increasing the FFT length and go deeper and deeper in distortion measurements. Noise would be limited to what we have now but it is well beyond our audible dynamic range so I think we are OK.
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
27,422
Likes
66,789
Location
Seattle Area
Thread Starter #8
Help please: I have LCD-3 headphones. I understand they have about 58 ohm impedance, flat across the full frequency range (https://www.innerfidelity.com/images/AudezeLCD3Rev2sn2613375circa2012.pdf). I'm trying to decide on the DX7 Pro or use a D50s DAC + Monolith THX 887 for the amp. Advice, please?
The amp in Monolith is better. Your headphone impedance is flat though so you should not have any audible issues with DX7 Pro. Personally I like the DX7 Pro combo as I noted in the review.
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
27,422
Likes
66,789
Location
Seattle Area
Thread Starter #9
Oh one note: this is a new product. I am not vouching for its reliability. Please don't buy it early and blame me if there are issues. :) My unit is working flawlessly so far.
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
27,422
Likes
66,789
Location
Seattle Area
Thread Starter #11
I used to do the sine waves. Problem is that you have to visually evaluate that. The linearity test shows that response in a measurable way.

On square wave, I have never run that and gain, linearity shows similar data in a quantitative way.
 

mi-fu

Addicted to Fun and Learning
Forum Donor
Joined
Jun 7, 2018
Messages
567
Likes
580
Location
New York
#16
As an owner of DX7s, I have to say I am slightly disappointed.

I thought Topping would fix the output impedance of the headphone jack to make it a perfect an all-in-one state-of-the-art DAC/headphone amp solution. Too bad it is still not there.

In such a case, D50s + Atom or Archel2 headphone amp probably will be a better choice and in fact even cheaper.

Now I really want to see how SMSL M500 performs.
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
27,422
Likes
66,789
Location
Seattle Area
Thread Starter #18
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
27,422
Likes
66,789
Location
Seattle Area
Thread Starter #19
Topping themselves specced it to be 4.7 Ohm for single-ended and 9.4 for balanced output so it's weird that Amir measured quite a bit higher than that.
My setup includes a bunch of wire and connectors. Companies measure it right at the terminal so get lower values. Mine is more realistic of what you get with a headphone.
 
Top Bottom