Topping A70 Pro HP & Preamp Review

[Sokel]

How did you acquire those signals?

A70 out to Focusrite in obviously,it's straight forward,says so on the window too.

 

[Ykar]

How did you acquire those signals?

A70 pro with no source, XLR or RCA out to my soundcard Focusrite Scarlett 2i2 (balanced inout for XLR, unbalanced input for RCA) with input gain at approx. 20% on the knob

 

[Moscardo]

A70 pro with no source, XLR or RCA out to my soundcard Focusrite Scarlett 2i2 (balanced inout for XLR, unbalanced input for RCA) with input gain at approx. 20% on the knob

In this case what you see seems the bouncing of a mechanical switch (probably a reed relay) used for muting. The real waveform is more complex but you need a real scope to see it. The RCA output uses a different method (electronic switch probably), maybe because of the lower amplitude signal.

 

[Ykar]

Some more fun, I added waves from an input signal as a reference for comparison.

 

[Moscardo]

Some more fun, I added waves from an input signal as a reference for comparison.


View attachment 328862

If the vertical scale is 5mV/div, that signal is only some mV amplitude. If the volume was at -60 dB (1/1000) this is correct.

 

[Ykar]

If the vertical scale is 5mV/div, that signal is only some mV amplitude. If the volume was at -60 dB (1/1000) this is correct.

A70's volume was at -50 think, close enough ? anyway I'm not sure of the absolute values in what I did, but what is 100% sure is the input signal and the noise were both measured in the exact same conditions for each output.

 

[Ykar]

Silver arrived, serial 23086550xx, sealed box (plastic film), firmware v1.07
--> again, speaker pop noise from XLR out when triggering internal relay (switching input/output/unmuting)... at least bad noise is now perfectly balanced on right and left channels, I guess I'm happier ? not sure... Tested RCA out, almost noiseless
Updated to v2.01, no change
I looked for any DC offset voltage out from power amp (Ncore) with each sources/output/mute states on A70- no difference (6 to 10mV)
"Oh, God, help me !" Metallica, One, ....And Justice for All, Track 04, 1988.

 

[Music1969]

This headphone amp is overall technically the best by Topping right?

 

[abc1234]

Silver arrived, serial 23086550xx, sealed box (plastic film), firmware v1.07
--> again, speaker pop noise from XLR out when triggering internal relay (switching input/output/unmuting)... at least bad noise is now perfectly balanced on right and left channels, I guess I'm happier ? not sure... Tested RCA out, almost noiseless
Updated to v2.01, no change
I looked for any DC offset voltage out from power amp (Ncore) with each sources/output/mute states on A70- no difference (6 to 10mV)
"Oh, God, help me !" Metallica, One, ....And Justice for All, Track 04, 1988.

Can you report this to Topping Support?

 

[JediMa]

Topping L50 is a good amp, but I would like something with more features (ports, remote, display ) so I was considering a A 70 pro, because of the more features, more power and not massive power supply hanging from AC. Is it a way to go or it's not worth it?

 

[Human Bass]

After an initial rocky road, now it's good to go

Topping L50 is a good amp, but I would like something with more features (ports, remote, display ) so I was considering a A 70 pro, because of the more features, more power and not massive power supply hanging from AC. Is it a way to go or it's not worth it?

 

[Phony846]

After an initial rocky road, now it's good to go

I have a very early model A70 Pro. Haven't had any issues. Are there confirmed hardware mods that the latest manufactured versions have which could head off future issues? Or is it entirely firmware based?

 

[Antagron]

As a follow-up to my earlier posts with the amp cutting out... The issue is much less pronounced now. I was playing with various sub 20Hz high pass filters, which seemed to help but didn't cure the problem. I also moved the amp to a different electrical outlet (it was sharing one with the RME DAC). This didn't seem to help. With more hours on the amp, the problem is far less frequent.. What I've noticed is that when the display is set to the VU meter, it cuts out all the time, but when set to the other 2 displays (like FFT), the cutouts are far more rare (though non-zero). Has anyone else noticed this? I have no idea why the VU meter display would make a difference in the amp's output, but it definitely seems to be correlated. Luckily I scored a Douk Audio L3 on 11/11 which has real VU meters, so I don't the VU on the A70. (would love to see Amir test an L3 at some point!)

 

[PacketofCrisps]

After an initial rocky road, now it's good to go

I'm looking into this amp, are you conforming all issues are fixed now?

 

[JediMa]

After an initial rocky road, now it's good to go

I have it here for 2 days and ... W O W.. all my planars now really sounds like they were meant to sound!

 

[Dunring]

We just came across the same problem with two A70Pro's so here is something to check for if you get one. At -31.5db in low gain there's a hiss in the right channel that tracked all the way to full volume when it vanished. It doesn't affect high gain, and two of these tested at two different locations with different DACs, cables, and headphones. It affected all the HP ports, and didn't matter if RCA or XLR was used for input. If you buy used, just do that simple test. The latest firmware update didn't change it, seems to be a hardware issue in early models. It's so specific, thought I'd mention it after the second one had the same problem.

 

[NexusOne]

I can’t decide between Topping A70Pro and Smsl D6s or Aune s9c. Can you help? They are nearly the Same Price.

+ More power
+ USB C
+ More settings

or

+ whole in one
+ more premium feeling (remote)
+ more musicality (?)

 

[Ahmonge]

I can’t decide between Topping A70Pro and Smsl D6s or Aune s9c. Can you help? They are nearly the Same Price.

+ More power
+ USB C
+ More settings

or

+ whole in one
+ more premium feeling (remote)
+ more musicality (?)

All-in-one, more convenient, less cables to worry about, etc.

 

[raif71]

After an initial rocky road, now it's good to go

I still need the fixed SN coz it's easier to check if I'm not getting the earlier "problematic" models, so appreciate if anyone can point this out. Thanks

 

[Bewateraudio]

I just received my A70pro yesterday and am noticing that a couple times every minute, I hear a relay and the sound stops (display Vu/FFT continues to work) and then it comes back. Is this a bad setting somewhere or has anyone else experienced this? Driving via XLR from ADI-2 DAC and outputting to Edition XS over XLR.

I have been experiencing the same thing -- have you found a solution?