Topping A70 Pro HP & Preamp Review

[nagster]

I don't know. Probably 9+ Vrms.

The only person I know who tests max input voltage is @nagster

See:

Topping A90 Discrete Review (Headphone Amp & Preamp)

I returned my A90D - much happier with my SMSL SP400 (47k ohm input impedance, also with stepped resistor relay volume control, and the best THX amp modulates AAA-888) No firmware issues. Any more info, happier.. why? ;)

www.audiosciencereview.com

Topping L70 Headphone Amp Review

Is anyone aware of the error codes that might come up on the L70? Mine came up with the code ‘r3’ when prompted to turn on via the 12V trigger, and then was unresponsive. I turned it off for a few seconds and then on again, and it’s now sweetly playing loud & clear again…

www.audiosciencereview.com

The A70pro seems like a very good HPA/preamp. However, I desperately searched for a reason to buy it, but there is already no place to install it. Hmm, toilet?
There is no surplus if it is a replacement, but there is no necessity to replace it. . .
I have attached part of the empty box.

 

[Veri]

The A70pro seems like a very good HPA/preamp. However, I desperately searched for a reason to buy it, but there is already no place to install it. Hmm, toilet?
There is no surplus if it is a replacement, but there is no necessity to replace it. . .
I have attached part of the empty box.

Yes. Toilet.

 

[August]

The A70pro seems like a very good HPA/preamp. However, I desperately searched for a reason to buy it, but there is already no place to install it. Hmm, toilet?
There is no surplus if it is a replacement, but there is no necessity to replace it. . .
I have attached part of the empty box.

Crazy fans!

 

[Sray]

The low gain balanced sensitivities are probably close to the limit of the balanced inputs. When the amp is internally single-ended, balanced inputs go through op-amps before attenuation, and these op-amps have voltage limits. Single-ended inputs, on the other hand, can be attenuated as they are and can take higher voltages.

Yep, it might clip the input stage. My previous experience when connect benchmarkmedia DAC3 without attenuation, ordinary preamp will clip even in very low output level.

 

[okok]

is this using the famous TPA6120 again???

 

[ra990]

Got this in today. I've owned quite a few Topping/SMSL products but this one feels higher quality. It has a nice weight to it, like the A90D. The volume feels good with clicking relays. The touchscreen is responsive and the display is actually very high quality. The menus provide a ton of options, like individual HP output selection toggle (first time in a Topping amp, I believe). Love the VU meter display. Driving my HE6SEv2 like a champ (in low gain).

 

[Blashyrkh]

The menus provide a ton of options, like individual HP output selection toggle (first time in a Topping amp, I believe).

The A70 pro menu provides the same options found in the L70 (plus those related to the display). Included individual output and Safe volume settings

 

[jruser]

Got this in today. I've owned quite a few Topping/SMSL products but this one feels higher quality. It has a nice weight to it, like the A90D. The volume feels good with clicking relays. The touchscreen is responsive and the display is actually very high quality. The menus provide a ton of options, like individual HP output selection toggle (first time in a Topping amp, I believe). Love the VU meter display. Driving my HE6SEv2 like a champ (in low gain).

Can you test the range on the remote for us?

 

[ra990]

Can you test the range on the remote for us?

Sorry, I didn't even unpack the remote as I don't plan to use it. The touch screen is pretty intuitive and responsive. I've kept the remote in the box and put the box away for now. Hopefully someone else who plans on using it can test this out for you.

 

[marcom22]

Can you test the range on the remote for us?

Yes can you test for us?

 

[AVKS]

Can a headphone with rated 32ohm be able to withstand the full 12.6W ?

Depends on the headphone driver.

 

[NexusOne]

The D70Pro is a bit expensive in comparison to the A70Pro. If the only point is sound quality with a hifiman headphone is there a big difference between Smsl D6 and D70 Pro or the best thing you can do is to save money and buy the A70Pro and D6 because you haven't got any big disadvantages?

 

[raif71]

The D70Pro is a bit expensive in comparison to the A70Pro. If the only point is sound quality with a hifiman headphone is there a big difference between Smsl D6 and D70 Pro or the best thing you can do is to save money and buy the A70Pro and D6 because you haven't got any big disadvantages?

My plan is to just get the A70Pro if I have sufficient funds of course . I'll just use any DAC that I already have with the a70pro. Part of the reasons getting the amp is it has more power, high input impedance and nice display (vu meter). Actually this is just a plan like I planned on getting the A90 discrete but decided not getting it at all. Plans can change.

 

[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?