• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Topping DX7 DAC & Headphone Amplifier Review and Measurements

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
44,370
Likes
234,415
Location
Seattle Area
This is a detailed review and measurements of the Topping DX7 DAC and integrated headphone amplifier. Frequent readers of this forum know that I am a fan of Topping D30 DAC. It measures excellently and is a bargain at $130 shipped. While the D30 has distinctly budget feel to it, such is not the case with Topping DX7. From cardboard packaging and custom foam to the heavy aluminum case the DX7 brings a much higher quality feel. It nearly rivals my Exasound E32 at 15 times the price. I purchased mine through Amazon for $299 shipped. Strangely it shows not available anymore: https://www.amazon.com/Balanced-Headphone-Amplifier-Topping-384KHz/dp/B073TRX2WC

upload_2018-1-25_23-13-16.png

Front panel as is an OLED display which has great contrast and gives nice confidence of what is being played as far as sample rates and formats (DSD and PCM).

Power supply is built-in which I appreciate very much. Topping boasts having regulatory certification which I appreciate (FCC and CE labels are underneath). It amazes me that audiophiles sweat noise/EMI yet go and buy hobbyist designed equipment that has no such certification and hence is likely to be bleeding badly on both fronts. That is on top of safety risks of mains powered equipment.

The Topping DX7 comes with an amazingly high quality custom remote control. It is made out of machined aluminum with excellent button tactile feedback. This picture does not do justice to it:

upload_2018-1-25_23-20-44.png

You can cycle through the filters with a dedicated button. The display can be dimmed but not turned off.

Connectivity is superb. We have both balanced and unbalanced analog output. There is also S/PDIF coax output. On the input side, we have full array of inputs from USB to Toslink and S/PDIF Coax input in addition to balanced AES. Most excellent!

The unit is heavy for its size and stays put when you mess with it.

The simple printed material comes with full suite of measurements made on $28,000 Audio Precision analyzer! It shames so many high-end companies that just provide useless specs or countless hobbyist DACs or China-special products that never verified their product to work properly.

Format support is also excellent with PCM sampling up to 384 Khz/32-bit and DSD up to DSD128. Wish it had DSD256 for completeness. Here is what Roon says about formats it detects from the DAC:

upload_2018-1-25_23-28-11.png

Really, I can't find anything to complain about here. For $299 this level of quality and feature set is a steal.

Measurements
Due to extensive functionality of the Topping DX7 I am dividing this task into two parts. What follows is the performance measurement of the DAC portion using USB and S/PDIF Coax input. In part 2, I will perform headphone measurements and comparisons.

Speaking of comparisons, the natural test was against Topping's own D30 stand-alone DAC. All testing is performed fresh (i.e. D30 measured together with DX7 for every test using identical cables/setup). Windows 10 in-built USB class driver is used (i.e. nothing installed).

First, our friend the J-test jitter and noise measurement at 24-bits/48 KHz sampling:

Topping DX7 vs Topping D30 Jitter Measurements.png


Looks like we have a linear power supply in the DX7 (good) which is generating that extra blip at 120 Hz (2X mains frequency) noise component (red). Pretty harmless though at such a low amplitude. Otherwise the rest of the performance is identical. For that reason, I almost stopped here thinking the rest of the measurements would be the same. I am glad I did not as that didn't turn out to be the case.

Here is a linearity test using S/PDIF input. The analyzer outputs a digital signal whose PCM representation gets smaller and smaller in amplitude. The measured analog output is compared to expected value and deviation plotted. An ideal DAC would have a flat line:

Topping DX7 vs Topping D30 Linearity Error.png


We see a remarkable improvement here in low level linearity/error. The Topping DX7 performs far better, easily delivering more than 18 bits of resolution. The D30 though only does well up to 15 bits or so.

Nex test is harmonic distortion of 1 Khz tone. Unlike previous measurements thought the 1 Khz tone is filtered out of the measurements. This reduces the noise level of the analyzer allowing us to really dig deep and see the spectrum of noise and harmonic distortion of the DAC being tested:

Topping DX7 vs Topping D30 THD Spectrum of 1 Khz 0dbfs 24-bit 44100 Khz.png


We see that the Topping DX7 (in red) has much lower noise floor. Its distortion spikes are more visible as a result but most of them are lower levels than Topping D30. Using the THD+N measure we have some 7 db of improvement.

Skinning this cat differently by sweeping our source signal frequency, we get a plot of distortion+noise relative to frequency:

Topping DX7 vs Topping D30 and Exasound E32 Distortion and Noise.png


Here, I have also included the Exasound E32 as I was starting to get worried that the Topping DX7 was as good as it. Looks like it is not quite but the DX7 easily beats the D30 again.

This is better seen in this new test: SMPTE IMD. This is a 60 Hz signal modulated by a 7 Khz tone with a 4:1 ratio. What is seen is the residual noise+distortion:

Topping DX7 vs Topping D30 and Exasound E32 SMPTE IMD Distortion Measurement.png


Good to see our measurements are consistent with Topping DX7 DAC beating the D30 again by a healthy margin. The Exasound E32 does even better (sigh of relief :) ).

Here is another new measurement: phase error between the left and right channels, given identical signal:

Topping DX7 vs Topping D30 Phase Error Measurement.png


The Topping DX7 wins again but these are small numbers with the D30 maximum error of just 0.4 degrees.

Lastly let's look at the frequency response measurements given the fact that the DX7 has three separate filters for PCM:

Topping DX7 Frequency Response Measurement.png


I am not sure if I messed with this before or not (I think not) but the default filter was the slow roll off which in my book is too slow. I like life in fast lane so I changed it to Fast setting which has the same steep drop off as minimum phase.

Summary
The topping DX7 DAC substantially raises the bar on functionality and performance in budget DACs. It is full featured and comes with everything you need. Measured performance is the best in this class so far with no fault to be seen. Yes, my $3,500 Exasound E32 beats it but this is remarkable performance at just $299 shipped!

The mechanical feel, volume control, remote, etc. are all excellent.

I have no choice but to declare the Topping DX7 the new reference for budget DACs. Highly Recommended.

As always, comments, corrections, questions, are welcome.

If you like this review, please consider donating funds for these types of hardware purchase using Patreon (https://www.patreon.com/audiosciencereview), or upgrading your membership here though Paypal (https://audiosciencereview.com/foru...eview-and-measurements.2164/page-3#post-59054).
 

Sylafari

Active Member
Joined
Jan 20, 2018
Messages
108
Likes
65
Thanks for the review and measurements.

The value proposition is insane indeed (makes me question my RME purchase just a little bit hehe)! The build quality looks great and it is made of aluminum instead of my RME's folded steel body and it even has a better remote than my RME ADI-2 DAC's plastic remote (which costs 3.3x more) and maybe a better screen (OLED vs IPS LED) although the RME has colors in it and has more functionality.

Do you plan on reviewing the amplifier portion (I don't believe seeing any measurements or much information on it). Also is a teardown planned?
 

Frank Dernie

Master Contributor
Forum Donor
Joined
Mar 24, 2016
Messages
6,445
Likes
15,780
Location
Oxfordshire
£310 at Amazon UK, which is $434 at the most recent exchange rate I have seen. which is much more expensive than the US, even taking the 20% tax off :(. Sadly this is all too usual.
 

Soniclife

Major Contributor
Forum Donor
Joined
Apr 13, 2017
Messages
4,500
Likes
5,417
Location
UK
Looks like an great product, thanks for testing it.

Can you clarify some things.

Does the volume control work in the analog or digital domain?
Are the single ended and balanced outputs active at the same time? Do they measure the same?
Do the line outs mute on headphone insertion?
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
44,370
Likes
234,415
Location
Seattle Area
Do you plan on reviewing the amplifier portion (I don't believe seeing any measurements or much information on it). Also is a teardown planned?

Yes to both.
 

Blumlein 88

Grand Contributor
Forum Donor
Joined
Feb 23, 2016
Messages
20,524
Likes
37,057
This Topping unit should be the perfect thing for those LSR305 mkII's. Should be a quality audio experience for $600.

If one wanted to add a sub, I am guessing you can use the RCA outs to the sub along with the balanced outs to the JBLs?
 

Eric Auer

Member
Joined
May 18, 2017
Messages
43
Likes
24
Great results.

Already a new revision out?
Wonder why? It wasn't old by any means.

Eric
 

stunta

Major Contributor
Forum Donor
Joined
Jan 1, 2018
Messages
1,155
Likes
1,399
Location
Boston, MA
The new one does DSD 512 and PCM 768k and has the new ESS 9038Q2M chip. Now a fully featured DAC/Amp combo. Wonder if the price is the same.

The new version does not show a remote in the contents list! I was waiting for Amir’s review before getting the DX7 but now it’s not available. Hope Topping brings it back in stock.
 

SpeedyRodent

Member
Joined
Jan 26, 2018
Messages
62
Likes
47
Location
Alberta, Canada
Hello,

New member here. Nice review and measurements!

I think Topping may have discontinued this DAC recently. I found this out when I tried to buy one a few weeks ago.

The unreleased DX7s is rumored to be more expensive. Can't remember if I read $499 or might have been higher.
 

DonH56

Master Contributor
Technical Expert
Forum Donor
Joined
Mar 15, 2016
Messages
7,835
Likes
16,497
Location
Monument, CO
Nice job Amir!

I found the DX7 at NewEgg and several other places but for $399 at all of them.
 

Thomas savage

Grand Contributor
The Watchman
Forum Donor
Joined
Feb 24, 2016
Messages
10,260
Likes
16,298
Location
uk, taunton
This is a detailed review and measurements of the Topping DX7 DAC and integrated headphone amplifier. Frequent readers of this forum know that I am a fan of Topping D30 DAC. It measures excellently and is a bargain at $130 shipped. While the D30 has distinctly budget feel to it, such is not the case with Topping DX7. From cardboard packaging and custom foam to the heavy aluminum case the DX7 brings a much higher quality feel. It nearly rivals my Exasound E32 at 15 times the price. I purchased mine through Amazon for $299 shipped. Strangely it shows not available anymore: https://www.amazon.com/Balanced-Headphone-Amplifier-Topping-384KHz/dp/B073TRX2WC


Front panel as is an OLED display which has great contrast and gives nice confidence of what is being played as far as sample rates and formats (DSD and PCM).

Power supply is built-in which I appreciate very much. Topping boasts having regulatory certification which I appreciate (FCC and CE labels are underneath). It amazes me that audiophiles sweat noise/EMI yet go and buy hobbyist designed equipment that has no such certification and hence is likely to be bleeding badly on both fronts. That is on top of safety risks of mains powered equipment.

The Topping DX7 comes with an amazingly high quality custom remote control. It is made out of machined aluminum with excellent button tactile feedback. This picture does not do justice to it:

You can cycle through the filters with a dedicated button. The display can be dimmed but not turned off.

Connectivity is superb. We have both balanced and unbalanced analog output. There is also S/PDIF coax output. On the input side, we have full array of inputs from USB to Toslink and S/PDIF Coax input in addition to balanced AES. Most excellent!

The unit is heavy for its size and stays put when you mess with it.

The simple printed material comes with full suite of measurements made on $28,000 Audio Precision analyzer! It shames so many high-end companies that just provide useless specs or countless hobbyist DACs or China-special products that never verified their product to work properly.

Format support is also excellent with PCM sampling up to 384 Khz/32-bit and DSD up to DSD128. Wish it had DSD256 for completeness. Here is what Roon says about formats it detects from the DAC:


Really, I can't find anything to complain about here. For $299 this level of quality and feature set is a steal.

Measurements
Due to extensive functionality of the Topping DX7 I am dividing this task into two parts. What follows is the performance measurement of the DAC portion using USB and S/PDIF Coax input. In part 2, I will perform headphone measurements and comparisons.

Speaking of comparisons, the natural test was against Topping's own D30 stand-alone DAC. All testing is performed fresh (i.e. D30 measured together with DX7 for every test using identical cables/setup). Windows 10 in-built USB class driver is used (i.e. nothing installed).

First, our friend the J-test jitter and noise measurement at 24-bits/48 KHz sampling:

View attachment 10194

Looks like we have a linear power supply in the DX7 (good) which is generating that extra blip at 120 Hz (2X mains frequency) noise component (red). Pretty harmless though at such a low amplitude. Otherwise the rest of the performance is identical. For that reason, I almost stopped here thinking the rest of the measurements would be the same. I am glad I did not as that didn't turn out to be the case.

Here is a linearity test using S/PDIF input. The analyzer outputs a digital signal whose PCM representation gets smaller and smaller in amplitude. The measured analog output is compared to expected value and deviation plotted. An ideal DAC would have a flat line:

View attachment 10195

We see a remarkable improvement here in low level linearity/error. The Topping DX7 performs far better, easily delivering more than 18 bits of resolution. The D30 though only does well up to 15 bits or so.

Nex test is harmonic distortion of 1 Khz tone. Unlike previous measurements thought the 1 Khz tone is filtered out of the measurements. This reduces the noise level of the analyzer allowing us to really dig deep and see the spectrum of noise and harmonic distortion of the DAC being tested:

View attachment 10196

We see that the Topping DX7 (in red) has much lower noise floor. Its distortion spikes are more visible as a result but most of them are lower levels than Topping D30. Using the THD+N measure we have some 7 db of improvement.

Skinning this cat differently by sweeping our source signal frequency, we get a plot of distortion+noise relative to frequency:

View attachment 10197

Here, I have also included the Exasound E32 as I was starting to get worried that the Topping DX7 was as good as it. Looks like it is not quite but the DX7 easily beats the D30 again.

This is better seen in this new test: SMPTE IMD. This is a 60 Hz signal modulated by a 7 Khz tone with a 4:1 ratio. What is seen is the residual noise+distortion:

View attachment 10198

Good to see our measurements are consistent with Topping DX7 DAC beating the D30 again by a healthy margin. The Exasound E32 does even better (sigh of relief :) ).

Here is another new measurement: phase error between the left and right channels, given identical signal:

View attachment 10199

The Topping DX7 wins again but these are small numbers with the D30 maximum error of just 0.4 degrees.

Lastly let's look at the frequency response measurements given the fact that the DX7 has three separate filters for PCM:

View attachment 10201

I am not sure if I messed with this before or not (I think not) but the default filter was the slow roll off which in my book is too slow. I like life in fast lane so I changed it to Fast setting which has the same steep drop off as minimum phase.

Summary
The topping DX7 DAC substantially raises the bar on functionality and performance in budget DACs. It is full featured and comes with everything you need. Measured performance is the best in this class so far with no fault to be seen. Yes, my $3,500 Exasound E32 beats it but this is remarkable performance at just $299 shipped!

The mechanical feel, volume control, remote, etc. are all excellent.

I have no choice but to declare the Topping DX7 the new reference for budget DACs. Highly Recommended.

As always, comments, corrections, questions, are welcome.

If you like this review, please consider donating funds for these types of hardware purchase using Patreon (https://www.patreon.com/audiosciencereview), or upgrading your membership here though Paypal (https://audiosciencereview.com/foru...eview-and-measurements.2164/page-3#post-59054).
I’m sending you virtual fish and chips , I could send you a virtual hug but know you’d rather think of battered cod and steaming fried potato in soggy newspaper ( newspaper is historically accurate to the memory I was referencing tho not used any more).

Great work .
 

Blumlein 88

Grand Contributor
Forum Donor
Joined
Feb 23, 2016
Messages
20,524
Likes
37,057
I’m sending you virtual fish and chips , I could send you a virtual hug but know you’d rather think of battered cod and steaming fried potato in soggy newspaper ( newspaper is historically accurate to the reverence memory tho not used any more).

Great work .

Glad you mentioned the newspaper. The place from my childhood had these British newspaper copy wrappers they used. I had forgotten that. It had a bunch of goofy spoof headlines from British history.
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
44,370
Likes
234,415
Location
Seattle Area
Nice job Amir!

I found the DX7 at NewEgg and several other places but for $399 at all of them.
Thanks Don. I just checked again and I did pay $299 including shipping. So maybe they were clearing them in time for new ones to come out.

I did some searching and people said the DX7s will come out in February. Maybe they thought originally it was going to come out end of last year.

I have a contact there and I may ask them what is going on.
 

RayDunzl

Grand Contributor
Central Scrutinizer
Joined
Mar 9, 2016
Messages
13,201
Likes
16,983
Location
Riverview FL
The new version does not show a remote in the contents list!

"According to what I’ve been told, the DX7s is going to feature upgraded components: the DAC will be an ESS Sabre ES9038Q2M (and two of them will be featured for a fully balanced implementation), supporting up to DSD512 (native) and 768 kHz PCM sampling. USB chip is going to be upgraded to XU208, which is the latest-gen controller from XMOS. They told me the amplifier chip is going to be upgraded, too. Remote control support is going away (alas)."

https://www.soundphilereview.com/news/topping-nx4dsd-dx7s-coming-soon-updated-ess-sabre-chips-1562/
 
Last edited:

Thomas savage

Grand Contributor
The Watchman
Forum Donor
Joined
Feb 24, 2016
Messages
10,260
Likes
16,298
Location
uk, taunton
Thanks Don. I just checked again and I did pay $299 including shipping. So maybe they were clearing them in time for new ones to come out.

I did some searching and people said the DX7s will come out in February. Maybe they thought originally it was going to come out end of last year.

I have a contact there and I may ask them what is going on.
It would be nice if they could lend you the new version to measure.
 

sssn

Member
Joined
Nov 1, 2017
Messages
92
Likes
74
Looking forward to the headphone amp review, however, I do not expect too much. According to Topping's specs, it's just another super generic, 10 Ohms output impedance, TPA6120A2 design. Not sure why Topping thinks we need yet another one of those, because there is a metric ****ton of those TPA6120A2 headphone amps out there, much cheaper ones at that.
 

Jimster480

Major Contributor
Joined
Jan 26, 2018
Messages
2,880
Likes
2,032
Location
Tampa Bay
Awesome review man! I've had one of these since it first came out and its a great unit. I actually output to a o2Amp because of the 10ohm output impedance not playing well with low impedance headphones.

I'm glad there is another forum now, Head-Fi has become far too communist with their advertising and pushing of brands that pay the admins.
 

drconopoima

Member
Forum Donor
Joined
Jan 14, 2018
Messages
51
Likes
40
For comparison, did you manage to test how many bits of resolution did the JDS Labs OL DAC have?
 
Top Bottom