WolfX700 Measurement of Topping A90 Headphone Amp

[maxxevv]

John Thanks - great work.
Is there a timeline for a 90 series dac/headphone amp all in one?

Thank you Vincent

You'll probably see a DX9 Pro in time to come I guess ?

 

[Matias]

I would love to see a D90+A90 based all-in-one product from Topping, this would be a killer product.

 

[Veri]

I would love to see a D90+A90 based all-in-one product from Topping, this would be a killer product.

I think, given the real estate in these boxes, separates D90+A90 will be better performing though.

 

[Megaderpbro]

Is there a known target price for this thing? I was thinking of buying an SP200, but I would also need a splitter and a preamp for running speakers. This would be a pretty damn convenient all in one option for that functionality. Obviously as a prototype there's a while yet to go till it releases, but I'll hold off on the SMSL if this would make budgetary sense, as it seems to be an engineering masterpiece.

 

[amadeuswus]

Composite + feedback. Basically the same as everyone else.

Congratulations JohnYang1997! Aka "The Destroyer," see this ASR thread: https://www.audiosciencereview.com/...review-another-champ.9438/page-12#post-249897

I am hoping the price will be $150 as projected by John , or at least no more than $300....

 

[Crazy_Nate]

Very nice! When I get around to replacing my Jotunheim, I'm going to seriously look at a D90 / A90 combo.

 

[Veri]

I am hoping the price will be $150 as projected by John , or at least no more than $300....

Looks like the A90 will be their balanced flagship amp. Probably the most costly offering..

 

[ck42]

Okay, well this just throws my HP amp plans out the window then!
@JohnYang1997 Anything news on the anticipated A50s....or timeline on the A90 availability?

 

[JohnYang1997]

Congratulations JohnYang1997! Aka "The Destroyer," see this ASR thread: https://www.audiosciencereview.com/...review-another-champ.9438/page-12#post-249897

I am hoping the price will be $150 as projected by John , or at least no more than $300....

There will be L30 (Atom/geshelli killer) A50s(A50 upgrade, perhaps 788 killer). This A90 thing is to fight 789 and 887. So don't expect this to be very cheap.

 

[amadeuswus]

There will be L30 (Atom/geshelli killer) A50s(A50 upgrade, perhaps 788 killer). This A90 thing is to fight 789 and 887. So don't expect this to be very cheap.

I am imagining a cratered, apocalyptic landscape with only silver and black Topping headphone amps left, scurrying around...

 

[MC_RME]

The performance of AP is certainly limiting that particular test. With extra test equipment like low noise preamp between the amp and AP, I would expect about 106dB of SNR at 50mV.

50 mV equals -23.8 dBu. Adding 106 gives -129.8 dBu, which I think is not reachable. Adding the max output level of 25.5 dBu (6.5 W in 33 Ohms) would result in a total dynamic range/SNR of 155.3 dB (RMS unweighted). That's not a competitor to the THX designs 789 and 887 (?), it would left them in the dust (888 has SNR 134 dB). I would be happy to eat my own words, but suspect this is a calculation error or measurement fault...

No worries, though, the rest is more than impressive enough!

 

[maxxevv]

50 mV equals -23.8 dBu. Adding 106 gives -129.8 dBu, which I think is not reachable. Adding the max output level of 25.5 dBu (6.5 W in 33 Ohms) would result in a total dynamic range/SNR of 155.3 dB (RMS unweighted). That's not a competitor to the THX designs 789 and 887 (?), it would left them in the dust (888 has SNR 134 dB). I would be happy to eat my own words, but suspect this is a calculation error or measurement fault...

No worries, though, the rest is more than impressive enough!

Think it was 95~94 dBu from the measurements at 50mV though.

If you're referring to this ??

 

[JohnYang1997]

50 mV equals -23.8 dBu. Adding 106 gives -129.8 dBu, which I think is not reachable. Adding the max output level of 25.5 dBu (6.5 W in 33 Ohms) would result in a total dynamic range/SNR of 155.3 dB (RMS unweighted). That's not a competitor to the THX designs 789 and 887 (?), it would left them in the dust (888 has SNR 134 dB). I would be happy to eat my own words, but suspect this is a calculation error or measurement fault...

No worries, though, the rest is more than impressive enough!

When using pot to output 50mV, everything before the output stage is essentially noiseless. The output stage only has a noise of 0.2x -0.3 uV.(not difficult using opa1612). And sure I wasn't clear about the test condition. I was talking about unbalanced output. And there must be a perfect return path from internal gnd to earth for clean LF. For the best 50mV performance unbalanced output should be used. For best full scale SNR balanced output should be used. I'm building an ultra low noise preamp to measure the noise of A90 as well as the new L30. 106dB really isn't that difficult. Even 110dB is achievable, just the matter of if it's worth it or not. I'll share the results when I finish.

 

[amadeuswus]

I have only admiration for Benchmark (the company), but I would still cheer if JohnYang1997 and colleagues were working on a Topping power amp that could compete with the Benchmark AHB2 for a third of the price. Or who knows, at the rate John is going, set new benchmarks.

 

[JohnYang1997]

I have only admiration for Benchmark (the company), but I would still cheer if JohnYang1997 and colleagues were working on a Topping power amp that could compete with the Benchmark AHB2 for a third of the price.

Less power yes.

 

[Matias]

Less power yes.

In my opinion one of the great features of AHB2 is the option of using it bridged and keeping high power with extremely low distortion. This is a 2-in-1 product for both owners of small or large systems.

 

[MC_RME]

Think it was 95~94 dBu from the measurements at 50mV though.

If you're referring to this ??

Again: 50 mV is the reference, max level, equalling -23.8 dBu of level. Measuring 95 dB means a real level of -118.8 dBu, which is the limit of the APx555 (see also my comment when Amir measured the IEM output of the ADI-2 DAC).

 

[gvl]

Kudos on the power switch, one no longer has to unplug the phones to use it as a preamp. Oh yeah, and the performance too.

 

[railcannon]

Why don't you measure the amplifier with real headphone load instead of resistive load?
You can read this article.
https://benchmarkmedia.com/blogs/application_notes/12838141-headphone-amplifiers-part-1

 

[MC_RME]

When using pot to output 50mV, everything before the output stage is essentially noiseless. The output stage only has a noise of 0.2x -0.3 uV.(not difficult using opa1612). And sure I wasn't clear about the test condition. I was talking about unbalanced output. And there must be a perfect return path from internal gnd to earth for clean LF. For the best 50mV performance unbalanced output should be used. For best full scale SNR balanced output should be used. I'm building an ultra low noise preamp to measure the noise of A90 as well as the new L30. 106dB really isn't that difficult. Even 110dB is achievable, just the matter of if it's worth it or not. I'll share the results when I finish.

When using pot to attenuate the input signal then the measurement is not comparable to all others so far done here. And the SNR that I calculated would not be available too, in that setting. Anyway, I don't want to cause the impression that I am critizing this development, so let's wait for your final numbers.