Review and Measurements of the Topping D70 DAC

[xevman]

Recently started running into an issue with my D70 where I get about 60 seconds of music before it cuts out to silence. Unplugging/plugging the USB cable back in resolves it to where I can get another 60s of music. Anyone else run into this?

This is a 2012 MBP running MacOS Catalina 10.15.6

Have you tried a different cable? I had the same issue and it ended up being the cable.

 

[Soundstage]

I know that the question is rather theoretical given audibility thresholds, but I when I look at the THD curve below, does it mean that I am better off plugging the D70 into an amp with a 26dB Gain rather than say 20dB?
I am thinking of buying a pair of Hypex NCORE MP250 (monoblocks) with 25dB gain to feed my Revel F208. What would then be the volume in the room if the DAC is set at -15dBs. I think that F208 have a sensibility of 88.5dB.

 

[Tusoli5]

Hello, I have followed your test with great attention and bought this wonderful Dac.
After using it in USB I was really disapointed with its sound that seemed incomplete, distorted and like out of phase.
I then used and amanero interface for converting usb to i2s and it went wonderfully naturel and easy to listen to.

So I measured my impulse in stereo with omnimic v2 on I2s, it showed this:

I did the same in USB and it showed a perfectly out of phase signal...

So I inverted phase on omnimic V2 mic in the program and naturaly got this back in place

So I inverted my speakers terminals to test it correctly and it went back to a real beautiful sound close to any other input on this dac.
Its USB isn't crappy it just is out of phase in its analog output...

I must add that proud owners of D70 I talk to have tried reverse polarity on their DAC to improve sound from USB and seem to have all the same great results and imporvments on this USB input from their Topping D70 DAC.

I wrote an e-mail to topping but if some could do so too, we would get a good chance to correct this bad mistake soon.

 

[SIY]

Polarity is generally unimportant sonically unless your speakers have massive even-order non-linearity and you're listening to test signals specifically optimized for the effect.

It might be worth reading Dick Greiner's research on this.

 

[Tusoli5]

Well it still produces sound, I agree with that, but just not the same way.
Your woofer for example goes in when it should go out. So it compresses its inner speaker chamber when it should radiate outside for creating an impact in your room.
Strictly the same sound but not the same way, thus not the same final effect.
If you inhale when you try to exhale under water you still produce respiration, just not with the same practical results.

 

[SIY]

Well it still produces sound, I agree with that, but just not the same way.
Your woofer for example goes in when it should go out. So it compresses its inner speaker chamber when it should radiate outside for creating an impact in your room.
Strictly the same sound but not the same way, thus not the same final effect.
If you inhale when you try to exhale under water you still produce respiration, just not with the same practical results.

Unfortunately, the analogy is not a good one. And evidence does not support audibility of polarity with music or voice material as opposed to test tones.

 

[Tusoli5]

The fact is this dac sounds a bit crappy in usb because of reverse polarity in USB, if you simply reverse your speaker connectors to compensate it all comes back to a beautiful sound as it is when you use I2s for example that doesn't present any polarity inversion. It isn't sure that all models suffer form this but if it does this simply is the cause.

It is what I heard that brought me to this testing and result. Not any theory that anything can be plugged in whatever polarity in audio world.

 

[SIY]

The fact is this dac sounds a bit crappy in usb because of reverse polarity in USB, if you simply reverse your speaker connectors to compensate it all comes back to a beautiful sound as it is when you use I2s for example that doesn't present any polarity inversion. It isn't sure that all models suffer form this but if it does this simply is the cause.

It is what I heard that brought me to this testing and result. Not any theory that anything can be plugged in whatever polarity in audio world.

Merely asserting this does not make it so. Correct me if I’m making a wrong assumption, but from reading your posts, it doesn’t appear that you did any actual listening test.

Here’s an easy way you can validate your claim: take a track that you believe shows a difference, create a file of this track with reversed polarity, then run an ABX test. If you score significantly, please post the logs and the files used.

 

[Tusoli5]

Merely asserting this does not make it so. Correct me if I’m making a wrong assumption, but from reading your posts, it doesn’t appear that you did any actual listening test.

Here’s an easy way you can validate your claim: take a track that you believe shows a difference, create a file of this track with reversed polarity, then run an ABX test. If you score significantly, please post the logs and the files used.

Well this might be a reading problem.
I am not here to write a book.

So I made listenings in both polarities and found the solution to the sound not being pleasant enough on this dac using USB. Then I validated it by taking measurements to be sur to understand what really happened in facts.

If it bothers you that this can happen I am sorry to offend you.
Anyway if you have this dac and find it strange in usb, try it and make abx test on your tracks you'll HEAR a difference.

 

[Veri]

Hello, I have followed your test with great attention and bought this wonderful Dac.
After using it in USB I was really disapointed with its sound that seemed incomplete, distorted and like out of phase.
I then used and amanero interface for converting usb to i2s and it went wonderfully naturel and easy to listen to.

So I measured my impulse in stereo with omnimic v2 on I2s, it showed this:

View attachment 92727

I did the same in USB and it showed a perfectly out of phase signal...
View attachment 92728

So I inverted phase on omnimic V2 mic in the program and naturaly got this back in place
View attachment 92735


So I inverted my speakers terminals to test it correctly and it went back to a real beautiful sound close to any other input on this dac.
Its USB isn't crappy it just is out of phase in its analog output...

I must add that proud owners of D70 I talk to have tried reverse polarity on their DAC to improve sound from USB and seem to have all the same great results and imporvments on this USB input from their Topping D70 DAC.

I wrote an e-mail to topping but if some could do so too, we would get a good chance to correct this bad mistake soon.

Honestly it's applaudable that you went and verified it. Question remains if this is just your unit or also other D70 units, hmm.
About phase, most people won't hear phase changes easily but some "golden ears" could. Archimago did some interesting tests:
http://archimago.blogspot.com/2019/06/musings-and-listening-on-absolute.html

 

[sutantoroy]

Hello, I have followed your test with great attention and bought this wonderful Dac.
After using it in USB I was really disapointed with its sound that seemed incomplete, distorted and like out of phase.
I then used and amanero interface for converting usb to i2s and it went wonderfully naturel and easy to listen to.

So I measured my impulse in stereo with omnimic v2 on I2s, it showed this:

View attachment 92727

I did the same in USB and it showed a perfectly out of phase signal...
View attachment 92728

So I inverted phase on omnimic V2 mic in the program and naturaly got this back in place
View attachment 92735


So I inverted my speakers terminals to test it correctly and it went back to a real beautiful sound close to any other input on this dac.
Its USB isn't crappy it just is out of phase in its analog output...

I must add that proud owners of D70 I talk to have tried reverse polarity on their DAC to improve sound from USB and seem to have all the same great results and imporvments on this USB input from their Topping D70 DAC.

I wrote an e-mail to topping but if some could do so too, we would get a good chance to correct this bad mistake soon.

I use Topping D70 USB connection too, and measure the impulse with Omnimic V2, its on the positive side.

 

[SIY]

Well this might be a reading problem.
I am not here to write a book.

So I made listenings in both polarities and found the solution to the sound not being pleasant enough on this dac using USB. Then I validated it by taking measurements to be sur to understand what really happened in facts.

If it bothers you that this can happen I am sorry to offend you.
Anyway if you have this dac and find it strange in usb, try it and make abx test on your tracks you'll HEAR a difference.

Not a reading problem, it’s a problem with extraordinary sonic claims with no experimental backup.

 

[Tusoli5]

Not a reading problem, it’s a problem with extraordinary sonic claims with no experimental backup.

I don't say extraordinary, I only say that USB finally meets other inputs.
But never mind, I don't claim to upgrade anything, only that many D70 have this default of very baaaad USB input. With very restrained bass, a bit too much harsh, on the bright side and scene presentation that seems not really in place compared to spdif/I2s/Aes, despite its input being a good xmos card implemented in the circuit.

When you get this difference between USB and other inputs, check it by reversing its analog polarity.
I am not talking about phase shifting on one frequency between others, just electric inverted phase. It is sure that not all the D70 are affected, but quite a signifant batch of this DAC is affected too.
I am not here to recreate the wheel, only to alert about inconsistencies in Topping D70 products from my experience and quite some other owners (not all) I know that had the same issue/measured effect after I told them. Nothing more.

 

[SIY]

You saw a polarity reversal. You have decided and claim here that this causes horrible sonic degradation. That’s an extraordinary claim. It requires evidence, otherwise it ranks with claims of alien abduction and anal probing.

Handwaving, repeated assertions, and inapt analogies are not evidence.

 

[Tusoli5]

Honestly it's applaudable that you went and verified it. Question remains if this is just your unit or also other D70 units, hmm.
About phase, most people won't hear phase changes easily but some "golden ears" could. Archimago did some interesting tests:
http://archimago.blogspot.com/2019/06/musings-and-listening-on-absolute.html

For sure this is the case with my unit and some users I could talk with about the same issue too. Some other users didn't have this inverted polarity after d/a conversion in usb. Problem is there is a quite large batch of these d70 that are built with this problem. I think it needs to be noticed somewhere.

 

[LTig]

Well this might be a reading problem.
I am not here to write a book.

So I made listenings in both polarities and found the solution to the sound not being pleasant enough on this dac using USB. Then I validated it by taking measurements to be sur to understand what really happened in facts.

If it bothers you that this can happen I am sorry to offend you.
Anyway if you have this dac and find it strange in usb, try it and make abx test on your tracks you'll HEAR a difference.

No one disputes your finding about wrong polarity - you even measured it. We dispute the effect this has on the sound. Chances are high that you became a victim of expectation bias. This happens to every human being because our brain is wired that way, hence no reason to feel offended.

The only reliable way to find out whether polarity is audible is to run the ABX test as described by @SIY in posting #1108. Swiching polarity in the source has the same effect on the output of the DAC as reversing the speaker connects, but it can be done without pause in real time.

 

[TomB19]

Tusoli5, you came to the wrong place for an objective discussion. To be fair, polarity inversion isn't that big of an issue, most of the time.

Reversed polarity has an impact on sound. Back in the 1970s, high end pre-amplifiers often had polarity inversion switches on the front panel.

For mono source material, I can't imagine it would make a difference but spacial queues have been mixed into a lot of stereo music. Frequenly, minute delays are added to one channel when mixing down a stereo record. Polarity inversion has an impact that varies with production techniques of a recording.

It's hard to imagine this being a problem with sample variation but perhaps it changes with software versions? Have you checked for a firmware update?

If you could get a second D70 with natural polarity, you could use them to bridge a pair of amplifiers.

 

[Tusoli5]

It's hard to imagine this being a problem with sample variation but perhaps it changes with software versions? Have you checked for a firmware update?

If you could get a second D70 with natural polarity, you could use them to bridge a pair of amplifiers.

Thanks for taking real interest and understanding in this matter. Topping came back to me and verified that their actual batch of construction are in electrical phase on usb. They started a series of identification with my dac to check.

I identified a bridge on pins 1 to 4 on usb in, on the back of the circuit. I took a picture and sent it to them. They aren't sure this connection is normal.
Firmware is up to date.

I was one of the early buyers of this dac so it could be a first batch from different construction site than what they produce today.
Anyway, Topping seems a bit helpful and concerned on the matter.
I'll let it be known when it'll go further.

 

[TomB19]

If I may express an opinion on this situation...

You present it as a major problem but it seems like it would be an extremely minor problem, worst case. At the core of this is the D70 being an expensive, high end, DAC. You don't deserve a good sounding device. You paid for a great sounding device so even a minor deviation from that is a major problem, exactly as you have expressed.

I feel your pain, brother. I hope Topping work through this with you. There is surely a good solution. You deserve a great D70 experience.

Kind regards.

 

[kkeretic]

For sure this is the case with my unit and some users I could talk with about the same issue too. Some other users didn't have this inverted polarity after d/a conversion in usb. Problem is there is a quite large batch of these d70 that are built with this problem. I think it needs to be noticed somewhere.

My D70 seems to work fine according to this. I bought it in January this year. But I found my SVS SB-1000 completely out of phase. OMG OMG OMG. If it weren't for your post I probably would never have noticed since I only rarely listen to amplifiers and speakers. And I’ve always wondered how the sub actually adds too little to the sound . Thanks a million times.