Topping D30Pro Review (Balanced DAC)

[Veri]

Those are so bullshit. Fuck those. Cost much higher than 4.4mm. So why in the fuck would anyone use that. We had that as an option but found it's purely impossible to use in a product.

It's a nice idea but yeah, gotta be realistic.

 

[gvl]

Not sure that you understand the issue. Beating transfers to IMD on any nonlinearity in the audio chain. For example in the speaker. That's the same principle like the CCIF test signal 19+20kHz transfers into 1kHz on any nonlinearity. Signal 19+20kHz itself creates beating which is a non issue, and the IMD tone 1kHz is an issue. Now, in our test, the DAC has created a twin tone, in our example, which was not in the original signal. If we have a 21kHz signal and poor filter attenuation, we get mirror at 23.1kHz, for 44.1kHz sampling frequency. We have a new tone 23.1 kHz which beats with the original 21 kHz at 2.1 kHz difference frequency. This would be a non issue if there was not a nonlinearity in the audio chain. But it is not the case, the nonlinearity is always there. The tweeter's nonlinearity will definitely create 2.1 kHz difference IMD tone which would be audible, though the original 21kHz and its 23.1 kHz mirror are both inaudible. And this is the potential issue. For this reason higher Fs of the source data, like 96 kHz, is always an advantage. Requirements to interpolation filter are much lower.

I agree that IMD is a potential issue. It is however an issue for both 19+20 and 21+23.1kHz tones, perhaps more in the latter case as 23.1kHz is an artifact of a slow filter. Your first post with the waveform implied that beating in itself was bad, which I don't think is right.

 

[TimW]

Those are so bullshit. Fuck those. Cost much higher than 4.4mm. So why in the fuck would anyone use that. We had that as an option but found it's purely impossible to use in a product.

I didn't expect such a strong response but okay.

 

[AnalogSteph]

Those are so bullshit. Fuck those. Cost much higher than 4.4mm. So why in the fuck would anyone use that. We had that as an option but found it's purely impossible to use in a product.

Whoops. Cost higher than 4.4 mm, which isn't a super budget connector to begin with? Bummer. It is to be seen how things pan out in the long term when tooling costs have been paid off, they're still quite new after all.

The WM8742 is not a new design... the CS43198 used in this DAC is actually the first "high end" design from the team that they acquired from Wolfson.

Ah. Makes sense now. The datasheets for these and the related CS43130/131 alone are super extensive and clearly indicate a high level of engineering. They basically put together some SOTA modulators on a 1.8 V process with Class H analog output (something previously available in headphone amplifiers e.g. from Maxim). I always thought the current AKM mobile DACs were clever, but these designs absolutely take the cake. (Oddly enough, I found details on high-performance modulators in a 2010 TI presentation, but they themselves had not actually exploited this by the looks of it.)

Moving on, I am continuously amazed at what these DACs can do. We need to develop better measurement equipment so that we can actually quantify the imperfections.

No kidding. You actually have to switch the Audio Precision to "high performance mode" for these, which enables some extra trickery. I am not sure whether there is any ADC out there that is on the level of this DAC. There are a few in pro studio space that at least claim a 130 dB or greater dynamic range (it was first done with hybrids 20+ years ago), but with distortion this low? I kind of have my doubts. AK5394A level was -110 dB THD+N.

It's impressive how much DACs have gotten better since 2007 when the WM8741/2 came out.

Well, yes and no. Wolfson deserve credit for bringing multibit delta-sigma converters to the masses, which was an important step. (One of those days I'll have to read up on how a converter manufacturer managed to spring up in Scotland seemingly out of the blue. Mind you, there had been a good bit of design expertise in the UK before.) ESS took the next one with the integration of ASRC. That said, DACs had gotten to a very high level of performance even before, and the really big steps had arguably already been taken:
PCM1794/1796 (2003): DR 127 dB, up to 132 dB in mono mode, THD+N 0.0004% (-108 dB)
AD1955 (2002): DR 120 dB, 123 dB in mono mode, THD+N -110 dB
PCM1738 (2000): DR 117 dB, THD+N 0.0004% (-108 dB)
CS4392 (2000): DR 114 dB, THD+N -100 dB (non-TOTL)
CS4396 (1999): DR 120 dB, THD+N -100 dB
AK4394 (1999): ditto
AD1853 (1999): SNR 117 dB, DR 116 dB (idle tones!), THD+N -104 dB (all 3 dB better in mono mode)
CS4391 (1999): DR 108 dB, THD+N -94 dB
Up to double speed only:
AK4393 (late 1998): DR 120 dB, THD+N -100 dB
CS4340 (1998): DR 100 dB, THD+N -88 dB (non-TOTL)
PCM1716 (1997): DR 106 dB, THD+N -96 dB
AK4324 (1997): DR 105 dB, THD+N -94 dB
Single speed only:
CS4390 (1997): DR 106 dB, THD+N -98 dB
CS4329 (1995): DR 105 dB (106 dB by 1998), THD+N -97 dB
AK4320 (1995): DR 100 dB, THD+N -84 dB
CS4328 (1993): DR 97 dB, THD+N -93 dB (-K) / -88 dB (-B)

DR given A-weighted.

If you wanted best dynamic range in the '90s, you'd generally come up with some contraption involving traditional multibit DACs or even hybrids. One of the Pacific Microsonics converters (don't remember whether Model One or Model Two) was reputed to be able to pull off <-120 dB of noise in loopback, way back in the mid-late '90s.

I should probably put all this together in a blog entry...

 

[PeteL]

The WM8742 is not a new design... the CS43198 used in this DAC is actually the first "high end" design from the team that they acquired from Wolfson. I'm excited to see Topping use it here. Thus far it's tended to be more common in portable devices or the odd high end pro audio design (like the Antelope Audio Amari), with little in between.

Heck, I didn't realize this product used such a pricy IC, ouch, I just looked it up, and I've read in this thread that the D30 pro use 4 of em. I wasn't seeing this, price TBD, but are we looking at some higher end, near flagship territory here? by Topping naming convention... 30 normally means cheap, this is an expensive design, unless they've really cut corner at PSU, but the numbers are good too...

 

[Vini darko]

Those are so bullshit. Fuck those. Cost much higher than 4.4mm. So why in the fuck would anyone use that. We had that as an option but found it's purely impossible to use in a product.

Don't hold back John tell us how you really feel

 

[Labjr]

Those are so bullshit. Fuck those. Cost much higher than 4.4mm. So why in the fuck would anyone use that. We had that as an option but found it's purely impossible to use in a product.

I'm curious to see the measurements of the Khadas. The rest of it seems like gimmickry.

I'm wondering why didn't the new D10?? have XLR jack?

 

[JohnYang1997]

I'm curious to see the measurements of the Khadas.

I'm wondering why didn't the new D10?? have XLR jack?

size = cost

 

[Rottmannash]

Don't hold back John tell us how you really feel

Nerve firmly struck

 

[pos]

@JohnYang1997 , any chance you or someone from your team could address my questions from post #182?

 

[JohnYang1997]

Very well done @JohnYang1997, really nice design and performance there!!
I like everything I have seen so far!
It looks like it might just be missing an AES3 input to be perfectly perfect for my use case, but I can certainly live without one if the rest is up to the task.
So, I have a few questions if you don't mind

1. Is there an ASRC on the spdif input and if so at what target frequency is it operating? (thinking about "syncing" multiple DACs)
2. What kind of DC output level can I expect (worse/typical) on the balanced output
3. Does the device remember its settings (volume and input selection) when turned off/on directly from the main
4. Does the device emit any kind of pop/click/noise when turned off/on directly from the main, or when syncing to a different input sample rate on the spdif input? Or in any situation really.
5. What is the idle power consumption?
6. How are thermal aspects handled, and would it be safe to let it turned on 24/7?
7. Can the screen be turned off (possibly with a delay) ?
8. Is the coax input transformer-coupled? What max voltage can it take? (would love to be able to connect an AES3 signal with minimum adaptation...)
9. What it the output impedance on each leg of the balanced output?
10. How are potential failures handled? (risks of DC output, 0dBFS noise, etc.)

1, Not sure but the dac seems working asynchronous.
2, Low but not sure what typical value is
3, Yes
4, yes but small
5, Low due to smps but no exact value. Will be included in manual.
6, Thermal is pretty good for D30pro. A30pro on the other hand can get quite hot. Stacking them makes both quite hot.
7, I think the screen can be set to auto off.
8, I don't think so(i prefer transformer at output). Not sure about the max voltage.
9, 20Ohm I think. Will be included in manual.
10, No dc protection.

 

[pos]

Thanks

 

[JohnYang1997]

Thanks

If you need some specific values, would you please ask me again after the holiday?

 

[AudioSceptic]

I have not heard back so I think they are on vacation.

Chinese New Year tomorrow (12 Feb).

 

[pos]

If you need some specific values, would you please ask me again after the holiday?

I will
Have a nice holiday!

 

[elnan14]

The only thing that this device lacks to make it perfect is bluetooth

 

[volkl77n]

Confusing!
A D30 that looks like an E30 plus a knob and we'll call it "Pro".

 

[gvl]

The only thing that this device lacks to make it perfect is bluetooth

On the contrary, lack of Bluetooth makes it perfect!

 

[Atanasi]

If you occasionally use Bluetooth, you can use a separate receiver like BC3 with SPDIF output. It is not perfect either but it does the job. It doesn't support hardware volume through Bluetooth, so Android has to disable Absolute Volume.

 

[pos]

Confusing!
A D30 that looks like an E30 plus a knob and we'll call it "Pro".

Add an AES3 input, remove the remote, and you get the D30ProPro