• 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!

Review and Measurements of Topping DX7s DAC and Headphone Amp

rickymiester

Member
Joined
Jun 7, 2018
Messages
8
Likes
3
I have connected DX7s to Windows 10 Pro (1803) + Core i 7-7700k PC, but I have experienced the same problem three times. I had a panic when the problem first occurred.

It was definitely terrifying when it first happened. Luckily the "quick fix" suggested by @mi-fu works for now.

Topping got back to me this morning asking if restarting the computer fixed the issue. I replied accordingly and mentioned the solution of completely unplugging the unit from the back is the only thing that works at the moment.

I will report back when they answer.
 

Toku

Major Contributor
Joined
Apr 4, 2018
Messages
2,391
Likes
2,776
Location
Japan
A problem also occurred today.
On my system, the following two kinds of errors occur.

1. The operation of Topping's USB driver abruptly stops, and the DX7s can not be recognized from the PC.
At this time, the status of the ASIO driver of Topping did not recognize DX7s at all.
2. Both the USB connection and the PC's audio player are working normally, but no analog output from the DX7s.

Previously symptoms occurred panic, but this time I was able to return to normal operation with reference to your advice.
The same symptom also occurs in Topping D50.
 

Toku

Major Contributor
Joined
Apr 4, 2018
Messages
2,391
Likes
2,776
Location
Japan
I bought 3 Topping D 10, D 50, DX7s so far. Out of the three, only D10 will work without problems.
Today, I ordered SMSL SU-8 to MassDrop for investigate the cause more. Since SMSL SU-8 is made with the same Chips configuration as DX7s, I would like to compare the operation.
 

esm

Active Member
Forum Donor
Joined
Apr 9, 2018
Messages
182
Likes
327
Location
Berkeley, CA USA
My remote arrived from AbiExpress today; I didn't have time to snap a photo, but it looks exactly like the pictures I'd posted. Solid aluminum body, with plenty of weight to it. Came with a small suction cup and tiny allen wrench to take the back off, as it needs a CR2023 battery (which wasn't supplied).
 

Toku

Major Contributor
Joined
Apr 4, 2018
Messages
2,391
Likes
2,776
Location
Japan
I judged that the cause of this problem was in the accessory USB cable and replaced it with the accessory USB cable for D10 and D50. The error did not improve. Therefore, I ordered a good quality USB cable at Amazon and replaced it. After that, this problem has not occurred.
 

JustIntonation

Senior Member
Joined
Jun 20, 2018
Messages
480
Likes
293
I have a DX7S coming my way arriving next week (and a decent quality UL-certified €3.- USB cable to hopefully prevent the above problem).
And I have a perhaps somewhat silly question.
As I understand it the balanced internals of the DX7S feed one DAC chip with a left and right signal and another DAC chip with the same left and right signal with polarity inversed (or perhaps one DAC chip with the left channel twice, once polarity inversed and the other DAC chip with the right channel twice, once polarity inversed). This balanced signal made up out of 4 channels is kept throughout the op-amps to the balanced outputs.
Out of curiosity I was wondering how the unbalanced line and headphone outputs are made. Are these simply taking 2 of the 4 channels and discarding the other 2? Or are the out of phase channels phase inverted again and combined with the in phase channels so the 4 channels combine into two for the unbalanced outputs?

It looks to me that the two out of phase channels are probably not used for the unbalanced output as the balanced output has twice the voltage. Or am I missing something here?
This means that when using the unbalanced outputs one ES9038Q2M, two OPA1612, one TPA6129A2 and a whole lot of other components are basically wasted?
If so, are there any gains to be had besides the extra volume to turn the balanced outputs into unbalanced outside the DX7S? And if one wants to do this, what's a good way of doing so?

Edit: Call me crazy, I was able to cancel the DX7S before it shipped after finding a second hand Anedio D2 (ES9018 full chip not mobile) for about the same price :) Comes with a host of measurements that exceed the DX7S and exactly the features I need.
 
Last edited:

yue

Active Member
Joined
Jul 21, 2018
Messages
275
Likes
294
Seems DX7s has much lager frequency response error than D30. The spec says it's 0.35 db while D30 is 0.03db. I think probably this is due to the usage of frequency oversampling filter, so you don't get a straight horizontal line in your frequency response measurement from 20-20kHz. I took a look at es9038q2m datasheet, and found theoretically you should get a straight line by using "linear phase fast roll off" or "minimum phase fast roll off" filter. Could you change your filter setting and see if it reduces the error? If that's the case probably they should update the spec.
 

vato3001

Member
Joined
Jun 1, 2018
Messages
12
Likes
4
Location
Germany
Where i can find the right cable now to use it here in Germany :D
 

JustIntonation

Senior Member
Joined
Jun 20, 2018
Messages
480
Likes
293
Where i can find the right cable now to use it here in Germany :D
I found this one in your neighbouring country, will surely be available in Germany as well.
https://www.onlinekabelshop.nl/eenvoudige-usb2-0-kabel-usb-a-usb-b-0-80-meter
Looks like it adheres to USB2.0 specifications, uses OFC for the wires which are well schielded and don't see why a more expensive cable would do any better.
Have not checked (nor will I be able to) if it indeed fixes the problem with the DX7S connection.
 

no1boss

Member
Joined
Jul 12, 2018
Messages
12
Likes
3
It's a shame Topping's stuff (also A30) have high output impedance otherwise I'd probably pick this up.
 

ripvw

Active Member
Forum Donor
Joined
May 31, 2018
Messages
281
Likes
450
Location
California's Central Coast
"What a revoltin' development this is!"

so, for the past two days no sound from the DX7s. Same problem that Toku and others have described - but with a new iMac instead of a PC. USB out from the DX7s is no longer recognized by the Mac - does not show up in System Preferences as a choice in Sound nor is it recognized when I run a System Report for USB. Up till now, I was able to get the intermittent DX7s up and running by rebooting the Mac - that stopped working last Thursday. Based on Toku's experience with Topping's USB cables I tried the only other USB 2.0 A-B I had available - the one from the D10 that will soon be on its way to my nephew to deliver USB to my old Benchmark DAC1. That USB cable worked with the DX7s until Sunday and then it failed. I picked up another 3-foot USB cable today and tried that - no joy. I removed the other two USB devices I had and ran it solo - nothing. Rebooting the Mac and the DX7s did nothing.

Since I still had the D10 around I hooked it up with the new USB cable and it was immediately recognized by the Mac. I turned on Tidal and configured it for the D10 - now able to get USB from the D10 into the DX7s via S/PDIF and TOSlink - both 44.1 and 96kHz work fine. How long this will work is the question as the DX7s worked most of the time I've had it - just lost connectivity from time to time. Will the D10 continue to work or will it fail or get intermittent as well? Obviously at this point I have absolutely no faith in Topping.

But let's say the D10 works until I need to deliver it to my nephew - a $90 solution to get USB to the DAC1. Had I known about the D10's ability to output USB via coax and optical a couple of months ago I could have saved myself the cost of the DX7s. And if you remember my previous post I paid $500 for the DX7s - no deal from Massdrop was available at the time. It's not quite a $500 paperweight but to make it work I need to spend another $90 for another DAC10 - oh joy...

I realize the vast majority of you own PCs and not Macs but if anyone has any other ideas please let me know. I will be talking to Apple about this and may end up taking the DX7s into the local Apple store and see if a "Genius" can help with a solution. Or I could sent it to Amir for analysis and/or to Topping - I bought it from Amazon but not sure what they can do about minimizing my cost to send it back. All ideas are welcome and thanks in advance.
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
44,370
Likes
234,416
Location
Seattle Area
Try this: when it doesn't work, unplug the USB cable from DX7s. Push its main knob until the display turns on and then plug it in before the display goes off. Let us know if it makes a difference.
 

ripvw

Active Member
Forum Donor
Joined
May 31, 2018
Messages
281
Likes
450
Location
California's Central Coast
Try this: when it doesn't work, unplug the USB cable from DX7s. Push its main knob until the display turns on and then plug it in before the display goes off. Let us know if it makes a difference.
can you give me a few more details - when I push the knob in it signals "See You" and then shuts off. Unless of course I just push it quickly and then it cycles through the inputs. What condition does the DX7s need to be in before I unplug the cable, push the knob and then reconnect the USB quickly?
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
44,370
Likes
234,416
Location
Seattle Area
can you give me a few more details - when I push the knob in it signals "See You" and then shuts off. Unless of course I just push it quickly and then it cycles through the inputs.
I am assuming you have it in its normal auto-power-off mode. If so, I like you to just wake it up with a button press. If it is already on, then what I suggested doesn't matter. :)
 

ripvw

Active Member
Forum Donor
Joined
May 31, 2018
Messages
281
Likes
450
Location
California's Central Coast
I am assuming you have it in its normal auto-power-off mode. If so, I like you to just wake it up with a button press. If it is already on, then what I suggested doesn't matter. :)
actually, I switched that feature off a few weeks ago thinking it would help. In any case, I tried the suggestion from mi-fu above and turned it off, unplugged everything (I unplugged AC as well) waited a few minutes and then plugged it back in and rebooted - success! I will try your method the next time it fails - not that I'm being negative or anything...
 

mi-fu

Addicted to Fun and Learning
Forum Donor
Joined
Jun 7, 2018
Messages
584
Likes
661
Location
New York
actually, I switched that feature off a few weeks ago thinking it would help. In any case, I tried the suggestion from mi-fu above and turned it off, unplugged everything (I unplugged AC as well) waited a few minutes and then plugged it back in and rebooted - success! I will try your method the next time it fails - not that I'm being negative or anything...

From my experience, i think you can purposefully make it "fail" again by restarting your mac while keeping your DX7s on and connected.

Restarting seems to somehow trigger the connection failure. (But, interestingly, if you use "shutdown" the mac, rather than "restart," it has no issue).

I also found that actually you don't need to unplug everything to "reset" the DX7s - You only need to turn off the DX7s by the main power switch from the back. Unplug USB. Turn on DX7s again, then connect the USB cable.

Not a huge nuisance to me. I just avoid restarting my mac unless absolutely necessary :D
 
Top Bottom