Topping A70 Pro HP & Preamp Review

[rocksteady]

6000mW x 2 @16 Ohms THD+N<0.1% 3000mW x 2 @32 Ohms THD+N<0.1% 1550mW x 2 @64 Ohms THD+N<0.1% 330mW x 2 @300 Ohms THD+N<0.1% 165mW x 2 @600 Ohms THD+N<0.1%

17000mW x 2 @16 Ohms THD+N<0.1% 12600mW x 2 @32 Ohms THD+N<0.1% 6000mW x 2 @64 Ohms THD+N<0.1% 1370mW x 2 @300 Ohms THD+N<0.1% 670mW x 2 @600 Ohms THD+N<0.1%

16W is only possible in balanced operation in 16ohm.

16W into your low imp IEM, by accident when lying on a table, will destroy it in milliseconds.

That's all very impressive and all, but let's be frank, who needs 16W into 16 Ohms? Even 6W is too much. On the other hand, this is yet another Extremely clean, powerful Amp into Low impedances, but rather underwhelming into High Impedances in SE mode. 165W into 600 Ohms is less than a quarter of the stated 670 mW in Balanced mode, and hardly impressive. Ditto for the 300 Ohm figures. Heck, my Violectric V100 debits 640 mW into 600 Ohms and over 1W into 300 Ohms, all of it through a 6.3mm Jack!
I keep hoping for a Modern, State of the Art Headphones amplifier at the right price (I thought the A30 Pro was it ), preferably Remote Controlled, that ticks all the boxes, but sadly this isn't it yet...

 

[rocksteady]

I don't think the RME guys are chasing the absolute measured performance, a contrario of these chinese brands. So I don't think they are so impressed, and if they would, they could do as well as Topping.

Sure, this new Topping combo is excellent and very nice looking too, and I love this fake retro vu-meter or the spectrum analyszer.
Two regrets though :

- no implementation of a digital EQ (RME's Dac have one, by the way) on the D70 Pro sabre
- the input imedance of the A70 Pro is 20 k, it's better than the 2 or 10 K of previous models, but still not fully universal, especially for some vintage analog components.
Input impedance of the RME is 40 K, and in the golden age of hifi, the standard was 47 k.

Dear Topping engineers and commercials, please do these two last efforts to get quasi perfection.

"Soundwise I don't think there will be any difference, I would have preferred more power for high impedance cans, and not 3kW for low impedance one."

This exactly. They offer Tons of largely unneeded power into low Loads but they are rather unimpressive into High Impedances. I really wished they would offer more even, or balanced, output across the Load range...

 

[rocksteady]

The 20k input impedance for an amp is so that the amp can match with more DACs that have a certain output impedance. The rule of thumb is that the amp should have at least 8x or 10x the impedance value of the DAC. For example, Denafrips Ares II has around 2k output impedance and L70 has 2k input impedance. This pairing obviously do not match as this is only 1:1 ratio and I guess one would get weird sounds from the pairing. If one were to upgrade the amp to A70pro, then the 20k impedance would have 1:10 ratio to the denafrips, so that would be perfect. Basically, the higher the impedance for an amp is so that it can better match with any DAC that connects to it.

edit : The Ares II's output impedances were even higher, at 2.4k ohms, balanced, and 1.2k ohms, unbalanced. So the example above if one were to use balanced connection between amp and dac

"Denafrips Ares II has around 2k output impedance" . Seriously? What a piec of Cr... Huh... Poorly designed gear.

 

[rocksteady]

Thanx for the reply.
Are you sure? I just checked Denafrips, it says 625 ohms. Most DACs have output impedances less than that. Any more and it is an oddity (cheapest Schiit DAC is at 100R). I must admit, any amp input impedance less than 5K is an oddity, too. I can only imagine such a low impedance input can only serve in an absolute lowest noise measurement competition. A competition between Topping and itself!
I would say, past 5K input impedance, it becomes irrelevant for most practical scenarios.

Denafrips Ares II | willowtreeaudio

The Ares DAC is a 20Bit/1536KHz, native DSD1024, discrete resistor ladder Digital To Analog Converter, also known as R-2R DAC.

www.willowtreeaudio.co.uk

View attachment 285213

625 Ohms or 1250 Ohms, either way, poorly designed gear. And it would be poor 30 years ago, let alone these days...

 

[rocksteady]

I also disagree with the Chi-Fi stigma in ASR but I let it go and follow their rules. They are the hosts, we are the guests, so we abide to their rules in their house, right?

Hey Matias. Nice to see you here. Remember me from Head-Fi several years back?

 

[Snoopy]

That's all very impressive and all, but let's be frank, who needs 16W into 16 Ohms? Even 6W is too much.

Negative gain, PEQ, convolution filters and low efficiency planer headphones, Sure it's a lot but there are probably headphones where you theoretically could use it and have some headroom left.

 

[moosso]

I found a review about A70 Pro with subjective opinion and some measurement data.

The author said it sound subjectively good but when he measure multitones with an actual headphone (Final D8000), he found the A70 Pro has higher IMD distortion in the treble compare to other amps.
A70 Pro with D8000:

Hypex DIYpreamplifier with D8000:

And playing square wave on A70 Pro will have peaks like this:

while under same condition other amps does not have this issue:

And topping is advertising their LA90 with "near perfect square wave performance":

Regardless it's audible or not, I have some questions:

• Can DAC/Amp "optimized" for APx555 but show worse response with actual headphone?
• What cause those peaks with square wave on A70 Pro?
• Do we need perfect square wave on Amp (not DAC) like sine wave?

 

[Blashyrkh]

• Can DAC/Amp "optimized" for APx555 but show worse response with actual headphone?

<gif>Michael Jackson eating popcorn</gif>

 

[Verig]

Real world load, overshoot, HF problems. Seems normal, the level is really low. But of course does not quite match their material.

 

[Verig]

Do we need perfect square wave on Amp (not DAC) like sine wave?

No. Square waves / impulses don't make sense for sound. If THD/IMD is ok I don't know why you'd take a look at squares. Is there an explanation for this test? And for Topping's advertising?

 

[shrimp_dude]

Anyone have a video or link to a video that shows the screen in action? You'd think a product with a screen with digital meters would be easy to find examples of it in motion.

 

[RangerAudio]

Anyone have a video or link to a video that shows the screen in action? You'd think a product with a screen with digital meters would be easy to find examples of it in motion.

There are no reviews out of the product, other than this one*. Which is sad. It's a promising product for sure.

 

[moosso]

I'm using Topping DX7 Pro+ currenctly and consider to upgrade, this looks attractive so I'm checking reviews about it.
About the real load test, I checked Hypex DIYpreamplifier's measurement, it has state of art performance too, I guess it just a hair better than A70 Pro for the high frequency IMD.

No. Square waves / impulses don't make sense for sound. If THD/IMD is ok I don't know why you'd take a look at squares. Is there an explanation for this test? And for Topping's advertising?

I know real world does not have square waves, but topping's material is a bit confusing me.
What's the difference if an AMP does not have overshoot issue? Can we see the difference from regular measurements?

Anyone have a video or link to a video that shows the screen in action? You'd think a product with a screen with digital meters would be easy to find examples of it in motion.

I found no videos too, only pictures.

 

[szaki1001]

I made a quick video of my own device, but I don't know how to insert it.

 

[staticV3]

I made a quick video of my own device, but I don't know how to insert it.

Upload it to YouTube, set the video to unlisted so that only those with the link can find it, then post the link here.

 

[szaki1001]

Upload it to YouTube, set the video to unlisted so that only those with the link can find it, then post the link here.

• I've never uploaded to YouTube, but I'll try!

 

[szaki1001]

 

[shrimp_dude]

Exactly what I wanted to see. Thanks!

 

[ObjectiveSubjectivist]

I'm using Topping DX7 Pro+ currenctly and consider to upgrade, this looks attractive so I'm checking reviews about it.

Wait till DX9

 

[szaki1001]

The drive is Ifi Neo Stream, 24 bit/xxx file.

Surprisingly fine sound, no sharp highlights. Perhaps due to the drive (iFi), a warmer tone, which is very good for many headphones.

Dynamics, stage, balanced sound. I love it! Sadly I sold my Hifiman HE1000SE headphones, and they would have winged it!