Topping DX7 Pro DAC and Headphone Amp Reviewed

[Triamping]

Might be a relais issue? Relais are famous for the "sometimes it works perfectly, simetimes no sound at all"

 

[kiyu]

Might be a relais issue? Relais are famous for the "sometimes it works perfectly, simetimes no sound at all"

not sure what is causing it, but is always the left channel and only on headphones out, xlr/RCA works fine, problem is that send it back to china es quite expensive..

 

[T.J. Turner]

I use my focal Elex with DX7 Pro + A90, adding a headphone amp means you don't use the amp section of DX7 pro so the issue of high output impedance is eliminated. I would recommend this combo, for space issue I am currently running DCA Aeon 2C with DX7 pro only and there is no difference to me compared to running it with both DX7 pro + A90.

Speaking of the Focal Elex, I'm curious about them with this amp. The single ended output is rather weak? With somethings like chilled out music or this Born Free John Barry soundtrack I'm listening to now I really have to crank it to -25- 20 on High gain in order for the music to sound engaging.

 

[kiyu]

Speaking of the Focal Elex, I'm curious about them with this amp. The single ended output is rather weak? With somethings like chilled out music or this Born Free John Barry soundtrack I'm listening to now I really have to crank it to -25- 20 on High gain in order for the music to sound engaging.

hmmm that's super strange according to drop elex is just 80ohms... 104 spl should be easy to drive.
I got the sen hd58x also from drop 150 ohms and I can drive it perfect at -18 /-16 in low gain

 

[ReaderZ]

Speaking of the Focal Elex, I'm curious about them with this amp. The single ended output is rather weak? With somethings like chilled out music or this Born Free John Barry soundtrack I'm listening to now I really have to crank it to -25- 20 on High gain in order for the music to sound engaging.

-25 is not really cranking it as it still has a lot of head room.

 

[T.J. Turner]

-25 is not really cranking it as it still has a lot of head room.

I'm not sure how the volume is supposed to work, but coming from -99db, -25db does seem a bit high. Compared to my THX 887, I never went above %50 on high gain and never went above %70 on low gain. With the DX7 pro I find myself at about %80 on high gain. But it's all relative I guess.

 

[Sanctum OF Bass]

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:

View attachment 36273​

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:

View attachment 36274​

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:
View attachment 36275

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:
View attachment 36276

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

Back to noise, here is our dynamic range:

View attachment 36277

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:
View attachment 36278

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:

View attachment 36279

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:
View attachment 36280

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:

View attachment 36281

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

View attachment 36282

Edit: forgot to include the filter response in the original review:
View attachment 36467

Headphone Amplifier Measurements
Measuring noise when the unit is outputting very little voltage (50 millivolts) gives us very good but not great results:
View attachment 36283
View attachment 36284

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:

View attachment 36285

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:
View attachment 36286

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:
View attachment 36287

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:
View attachment 36289

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

Output impedance is a bit high though:
View attachment 36290

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. 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/

It might be a redundant and possibly stupid question but I am curious as to how the distortion measurement for the 4 pin headphone XLR output would test at the low 50mv 600 ohm test. If the 4 pin XLR output was so strong why skip testing that specific 4 pin xlr output under the same scenario? Also that leads me to the even smaller headphone connector (not sure if it’s trrs) output measurements .

 

[Martin]

-25 is not really cranking it as it still has a lot of head room.

I regularly listen to my Audeze LCD-3 between -15 & -10. Any louder is too loud.

 

[Toku]

I need to send back my Dx7 pro to china, but I guess 1 of the opamps (LME 47920 originals) is failing , because like 90% of the time that I switch from P+L to PO , I lost the left channel on my headphones... if I go back to P+L something fixed the issue sometimes left channel only work in RCA/xlr but not in headphone ... really strange issue.

From your symptoms, I think the cause is poor contact of the relay contacts.
Try repeating the switching operation 100 to 200 times. As a result, the contact of the contacts may be restored and normal operation may occur.
I ran into the same problem with the input switching of the PA3 Pro + I purchased the other day.
As a result of repeating the switching operation 100 times or more, it now works normally.
I used to use Japanese-made relay parts for audio equipment made in China, but nowadays I often use Chinese-made relay parts.
Unfortunately their quality is not very good.
The omron G6K-2P-Y is used in the picture of the HP PC board, but it is actually unknown.

 

[ReaderZ]

I regularly listen to my Audeze LCD-3 between -15 & -10. Any louder is too loud.

I think when I had the LCD-3 I was at around -27, I do listen at very low volume

 

[Toku]

From your symptoms, I think the cause is poor contact of the relay contacts.
Try repeating the switching operation 100 to 200 times. As a result, the contact of the contacts may be restored and normal operation may occur.
I ran into the same problem with the input switching of the PA3 Pro + I purchased the other day.
As a result of repeating the switching operation 100 times or more, it now works normally.
I used to use Japanese-made relay parts for audio equipment made in China, but nowadays I often use Chinese-made relay parts.
Unfortunately their quality is not very good.
The omron G6K-2P-Y is used in the picture of the HP PC board, but it is actually unknown.

I'm sorry, I made a mistake in the model number of the model. It was a mistake of PA3s, not PA3 Pro +.

 

[forgey]

Hi! Just wanted to ask if this is still worth the purchase. I've been meaning to upgrade my gear for a while and since I decided to do it I wanted something that was future proof. Main reason this is my first choice is because its accessible, I can get it somewhere with good warranty, and has a good form factor. I'm just hesitating right now because I'm seeing a lot of praise for other topping product that come up cheaper than this (even as a stack) which is also available with good warranty to me. There's also the matter of this supposedly not having a great HP out, though I don't think it matters to me right now as I just have a 6XX and IEMs, it does leave some concern should the day come I get more phones though

 

[mrbungle]

Hi! Just wanted to ask if this is still worth the purchase. I've been meaning to upgrade my gear for a while and since I decided to do it I wanted something that was future proof. Main reason this is my first choice is because its accessible, I can get it somewhere with good warranty, and has a good form factor. I'm just hesitating right now because I'm seeing a lot of praise for other topping product that come up cheaper than this (even as a stack) which is also available with good warranty to me. There's also the matter of this supposedly not having a great HP out, though I don't think it matters to me right now as I just have a 6XX and IEMs, it does leave some concern should the day come I get more phones though

Mine has its first anniversary coming up soon and I still enjoy it a lot. The Topping EX5 is cheaper and seems now the standard recommendation in this class, but might not be that accessible. Dx7pro amp is plenty powerful for me, at least in balanced. People complain about the high impedance, so could affect the frequency response of your IEMs. Dx3 Pro+ is the little brother and might be all you need.

 

[Triamping]

I would love to test it with SparkosLabs SS3602 , but to d@mm expensive unfortunately. and I don't think I will hear a really big difference.

Since you mentioned it, I'm sharing a recent review, though non-scientific and opinion-based still honest audiophile headphone (amp) reviewer:
Discrete Op-amp Round-up - Burson vs Sparkos vs Staccato

Although I'm undecided (wheather or not its wise to change OP-Amps) I wonder which genius houses heat generating Discrete OP-Amps inside plastic housings that lower ventilation and longevity. I want to be a believer, but simple flaws like these makes me question the validity of the praisals that are echoed on the internet. Before you know it somebody will say: "Its intentionally designed to operate at a hot temperature for a more lush and open sound!" And again, who am I to judge their bias wrong or right (pun intented).

 

[dartinbout]

IMHO, skepticism should always be the default stance for any claim promising benefits that do not meet the OP (or anybody's) body of experience. That being said, I've a set of Burson Viivd 6 in my DX7 preamp. I've been listening to DSD256 continuously for 6 hours and the DX7 case is cool to the touch. I also have a set of Sparkos that I've used and did not notice any thermal issues. I've also used both mfg.'s in my Auzentech Meridian, installed in an open pc case, and neither of them ever became hot to the touch.

 

[PKAWA]

I was wondering if there's a way to turn the display off while in use?
I have this device, and would like it to only light up when changing values.

 

[dartinbout]

I set the DX7 to DAC only, opened it up to change the op-amps and disconnected the ribbon to the front panel. That disables the remote and completely eliminates the display. I contacted Topping support to see if I could achieve what you want. This was the only option they offered.

 

[PKAWA]

I set the DX7 to DAC only, opened it up to change the op-amps and disconnected the ribbon to the front panel. That disables to remote and completely eliminates the display. I contacted Topping support to see if I could achieve what you want. This was the only option they offered.

Okay thanks. That doesn't work for me, but at least I can stop searching for the option.

 

[Toku]

Has DX7Pro been discontinued?
At Japanese distributors, DX7Pro has been discontinued and has factory inventory only and announcements.

 

[dartinbout]

It's not listed on Apos but I did find one on EBay. Topping seems focused on small footprint equipment and MQA. Neither of which I care about in audio reproduction.

I really like the DX7Pro but I have been a big fan of Op-Amp rolling for 15 years. Having one chassis, that can be modified so easily to achieve dramatically different sound signatures, pleases me to no end.