Topping A50s Headphone Amplifier Review

[Thalis]

It's pre out. Meaning the volume control is still enabled.

Ok got it . After years of using the E10k I actually much prefer a fixed 2V Line Out...

 

[JohnYang1997]

Yes, the two are different animals. Balanced input is designed to get rid of currents that flow between chassis of two pieces in the audio chain, causing ground loops. Balanced input eliminates this and can be a great help in reducing chances of hum and noise induced from the upstream PC.

Balanced output should not have been called that. There is no ground reference with headphones so all outputs are "balanced in nature." In this context then its main value is potential for quadrupling output power.

Having the chain inside the device be balanced/differential is of little value and independent of the above.

On the balanced, I think I might disagree a bit on that. Balanced is from the impedance perspective. Ideally, the output impedance of hot and cold of the amp, the connector, the cable to the headphone all need to have equal impedance. Headphones are balanced in nature but once you have the 3pin cable it's not balanced anymore. Same goes for the amplifier output the GND is not the same as the output signal in impedance. Especially for traditional unbalanced connector like 6.35mm. Single-ended output amp like SP200, HPA-4 with XLR connector may get away with that in practical sense. Impedance is close enough for each of the 4 signals.
To avoid confusion, surely differential signaling is more appropriate and representative to what we usually think balanced means.

 

[raif71]

It's pre out. Meaning the volume control is still enabled.

In pre out mode, will the gain switch make a difference at rca out? Thanks

 

[Thalis]

In pre out mode, will the gain switch make a difference at rca out? Thanks

I was about to ask the same thing

 

[gvl]

In pre out mode, will the gain switch make a difference at rca out? Thanks

In these designs the pre out is usually tapped to the headphone output so it tracks it.

 

[JohnYang1997]

In pre out mode, will the gain switch make a difference at rca out? Thanks

Yes.

 

[kkeretic]

There are many reasons for A50s to exist otherwise it wouldn't.
Firstly it's an upgrade to the sort of failed A50.

I would really like to know what's so wrong with A50? Is Topping actually ashamed of that device? Is "fail" a reason why that device has never been tested here, so that it may not swing Topping’s reputation? No, seriously, what's so wrong with A50 considering I haven’t read a bad review about that device on the net yet, and I found them more than a few? Is it somewhat higher output impedance, use with IEMs, switch instead of preamp, neutrality issues, noise, distortion or something else? Interested because I have two of them and really can't compare them with anything except Xonar soundcards and some old integrated amps with pretty bad headphone outputs.

 

[JohnYang1997]

I would really like to know what's so wrong with A50? Is Topping actually ashamed of that device? Is "fail" a reason why that device has never been tested here, so that it may not swing Topping’s reputation? No, seriously, what's so wrong with A50 considering I haven’t read a bad review about that device on the net yet, and I found them more than a few? Is it somewhat higher output impedance, use with IEMs, switch instead of preamp, neutrality issues, noise, distortion or something else? Interested because I have two of them and really can't compere them with anything except Xonar soundcards and some old integrated amps with pretty bad headphone outputs.

It didn't live up to the expectations of people (me included at the time as well when I was not a designer here yet). It literally didn't sell a single unit in China the day of release. It's not really that bad comparing to many other products from other companies like IFI, Schiit(at the time), FIIO etc.
People expect THX performance, at least Atom. It's not even as good as Dx3pro V1.
You can still find the specs and graphs somewhere. It's ok but not impressive.

 

[kkeretic]

People expect THX performance, at least Atom. It's not even as good as Dx3pro V1.
You can still find the specs and graphs somewhere. It's ok but not impressive.

Well, no doubt the latest products you made are impressive on paper (I believe in practice as well). But the right question would be is there a justified "sonic" reason to do an upgrade to A50s/L30 from A50 or something similar if using some "ordinary" headphones like Sennheiser HD599/HD600/HD650, AKG K712, HiFiMAN Sundara...? Would the A50s or L30 give a noticeably better sound in any way to these cans? I understand that this is probably an awkward question for you, but... If I could test and compare those devices myself, well...

 

[JohnYang1997]

Well, no doubt the latest products you made are impressive on paper (I believe in practice as well). But the right question would be is there a justified "sonic" reason to do an upgrade to A50s/L30 from A50 or something similar if using some "ordinary" headphones like Sennheiser HD599/HD600/HD650, AKG K712, HiFiMAN Sundara...? Would the A50s or L30 give a noticeably better sound in any way to these cans? I understand that this is probably an awkward question for you, but... If I could test and compare those devices myself, well...

Only concern from me is the noise with sensitive IEMs. Then it may sound a little bit "excited" due to relatively high noise in the high frequency. If you have one and it works for you then it's great. You don't need to upgrade.

 

[solderdude]

Would the A50s or L30 give a noticeably better sound in any way to these cans?

I don't think so for the listed headphones.

 

[digititus]

@JohnYang1997 - Solid looking product. Congrats.

 

[raif71]

Only concern from me is the noise with sensitive IEMs. Then it may sound a little bit "excited" due to relatively high noise in the high frequency. If you have one and it works for you then it's great. You don't need to upgrade.

I will basically use this amp with my Senns hd6xx series but occasionally I may use some iems. Suppose I find the iems like you say a bit "excited", is it ok if I use such adapter https://www.amazon.com/FAAEAL-Conductor-Impedance-Cancelling-Professional/dp/B07FM8GJL4 ?

 

[solderdude]

Probably not. The high impedance is only suited for specific IEM's.
Instead use the ifi or G1217 attenuator or build one yourself.

 

[Veri]

is it ok if I use such adapter https://www.amazon.com/FAAEAL-Conductor-Impedance-Cancelling-Professional/dp/B07FM8GJL4 ?

Better get an iFi ear buddy / iEmatch thingie which will work a lot more reliably than a cheap $7 impedance filter.
Edit: As solderdude just mentioned.

 

[yavormoskov]

I have a question. We now not the objective measurements. My question is more about the subjective music enjoyment experience. Not counting for the power handling difference, are there any sound differences between the single ended from L30 and the balanced 4.4mm from A50s? If the volume is properly matched and I plug in headphones back and forth between both, would I or anyone else be able to hear a difference? Maybe, JohnYang1997 could share his opinion

 

[solderdude]

Not when you use the TRS jack output.
There could be a very small audible difference when using balanced cables with some specific low impedance headphones when also swapping between certain cables.
In general ... no there won't be an audible difference.

Ask the same question in 'subjective based' forums and they will say there is, for a number of reasons. Some will say both amps wil sound lifeless, boring and whatnot. This will be based on biases about the brand, gurus and reviewers telling them so and comparisons with 'pleasantly tuned' amplifiers and uncontrolled tests.
Of course the last bit is my opinion.

 

[ElNino]

Is there less crosstalk when using a balanced/differential connection to headphones?

One thing I've noticed with unbalanced headphones regardless of amp is that if I play a signal only in the left channel, turn up the volume fairly loud, and then listen only through the right channel, I hear a faint musical signal in the right earcup. I'm assuming this is due to crosstalk through the common ground. Does it go away with a balanced connection?

 

[Atanasi]

Is there less crosstalk when using a balanced/differential connection to headphones?

Yes:
Single-ended headphone output Jack 6.35mm : -86dB @ 1kHz
Balanced headphone output Jack 4.4mm : -128dB @ 1kHz

 

[solderdude]

Is there less crosstalk when using a balanced/differential connection to headphones?

One thing I've noticed with unbalanced headphones regardless of amp is that if I play a signal only in the left channel, turn up the volume fairly loud, and then listen only through the right channel, I hear a faint musical signal in the right earcup. I'm assuming this is due to crosstalk through the common ground. Does it go away with a balanced connection?

Yes, the severity is cable and headphone impedance dependent and can be as severe as -30 to -40dB i.e. just in the perceptable range with some recordings.
That is.. when a common return (ground) wire is used.
It affects stereo imaging only.
Sennheiser cables are 4 wire and connect in the TRS plug only so the problem is not always present when looking at single wire cables.