Topping A50 III Headphone Amp Review

[KrispyJuniors]

Can anyone provide any insight on the actual topology of this amplifier?

I was under the impression that it is a bridged/floating output due to the measurements, product description and marketing language. The slightly lower SNR and slightly higher distortion pointed me to a summing/conversion stage. A bridged topology would make sense for the size and price of the amp. I was pretty confident in this conclusion, but I recently noticed a couple of Topping's fully differential amplifiers, such as the A90D and L70, exhibit similar measurement characteristics as the A50 III. This has really piqued my curiosity.

Does anyone know if the A50 III maintains a differential signal path from the input to the output, or if the balanced input is converted to single ended before the output stage. Can anyone find any concrete answers or a teardown to confirm?

 

[Roland68]

Can anyone provide any insight on the actual topology of this amplifier?

I was under the impression that it is a bridged/floating output due to the measurements, product description and marketing language. The slightly lower SNR and slightly higher distortion pointed me to a summing/conversion stage. A bridged topology would make sense for the size and price of the amp. I was pretty confident in this conclusion, but I recently noticed a couple of Topping's fully differential amplifiers, such as the A90D and L70, exhibit similar measurement characteristics as the A50 III. This has really piqued my curiosity.

Does anyone know if the A50 III maintains a differential signal path from the input to the output, or if the balanced input is converted to single ended before the output stage. Can anyone find any concrete answers or a teardown to confirm?

As far as I know, in the A50 III, the balanced input signal is immediately converted to unbalanced and only becomes balanced again right before the output stages. The same applies to the L70, A70 Pro, A90D, and so on.
Balanced signal transmission only makes sense externally—outside the devices. Internally, it offers no advantages and creates more problems than it solves.
Some people believe that balanced internal signal paths are something great or special, but ideally, balanced signals are converted to unbalanced at the input and only converted back to balanced at the output.

There are a few rare exceptions—headphone amplifiers with fully balanced signal paths—but their measurements show that there is no advantage to this approach.

 

[KrispyJuniors]

As far as I know, in the A50 III, the balanced input signal is immediately converted to unbalanced and only becomes balanced again right before the output stages. The same applies to the L70, A70 Pro, A90D, and so on.
Balanced signal transmission only makes sense externally—outside the devices. Internally, it offers no advantages and creates more problems than it solves.
Some people believe that balanced internal signal paths are something great or special, but ideally, balanced signals are converted to unbalanced at the input and only converted back to balanced at the output.

There are a few rare exceptions—headphone amplifiers with fully balanced signal paths—but their measurements show that there is no advantage to this approach.

Thanks for the sanity check! This is what I was thinking too, but I have been having trouble wrapping my head around the architecture. I figured for the size, price and complexity, it pretty much had to convert to single ended at the inputs. You're right, the measurements are so good, fully balanced wouldn't be worth the complexity.

 

[Roland68]

I get the feeling you’ve read some incorrect information somewhere about balanced devices or signal paths.
Balanced external signal transmission—such as via XLR cables—and internal balanced circuitry are two completely different things; they have nothing to do with each other.
While balanced cabling offers distinct advantages—such as the ability to eliminate interference, even over long cable runs—the situation is exactly the opposite for internal circuitry. Factors like component tolerances, volume control discrepancies (e.g., quad potentiometers), uneven interference pickup, and mismatched resistances within a balanced signal path actually degrade signal quality rather than providing any benefit.
The only practical application is in power amplifiers, where balanced amplifier stages allow for a fourfold increase in power output for a given power supply voltage. However, the noise components also add up, which is why the effort in development and tolerances in production are much more complex in order to obtain good measurement values.
In terms of sound quality, balanced amplifiers offer absolutely no advantage either.

This is clearly demonstrated by single-ended amplifiers like the Topping L30 II, L30, and L50, which consistently top the measurement charts, outperforming almost all balanced amplifiers.
The fact that the A50 III matches these models in measurements is a testament to the quality of its engineering.

 

[toumpouris]

Hey everyone!
I would like to try a headphone amp, and this model is of my interest to purchase.
Right now I use RME Fireface 802 MK1.
Do you think is worth the upgrade? Anyone tried this and can compare?
I have neumann ndh30 and beyerdynamic dt 770 pro 250 ohms.

Thanks!

 

[davmol]

Hey everyone!
I would like to try a headphone amp, and this model is of my interest to purchase.
Right now I use RME Fireface 802 MK1.
Do you think is worth the upgrade? Anyone tried this and can compare?
I have neumann ndh30 and beyerdynamic dt 770 pro 250 ohms.

Thanks!

I can't compare but they seem like apples and oranges? The topping being consumer oriented desktop headphone amp and the RME being a studio audio interface. I have the DX5-II and am very very happy with it, so if you want a small form factor powerful headphones amp with dsp then I don't think you'll do much better at this price point. Also worth considering the DX1-II as well if you don't need the Bluetooth and the power of the DX5, because your can save a chunk of change.

Edit, just noticed this is for the A50III haha! I must be subscribed to too many threads! Anyway, as luck would have it, I also have owned the A50III and A50S and they were both superb little amps, you can't go wrong, although again might be worth considering the DX1-II from a feature Vs price point. If you wanted an analogue input so you could use your RME DAC, then the Fosi ZH3 was also a nice headphone amp, with additional DAC features should you need them in future, such as usb input from a pc etc.

 

[toumpouris]

I can't compare but they seem like apples and oranges? The topping being consumer oriented desktop headphone amp and the RME being a studio audio interface. I have the DX5-II and am very very happy with it, so if you want a small form factor powerful headphones amp with dsp then I don't think you'll do much better at this price point. Also worth considering the DX1-II as well if you don't need the Bluetooth and the power of the DX5, because your can save a chunk of change.

Edit, just noticed this is for the A50III haha! I must be subscribed to too many threads! Anyway, as luck would have it, I also have owned the A50III and A50S and they were both superb little amps, you can't go wrong, although again might be worth considering the DX1-II from a feature Vs price point. If you wanted an analogue input so you could use your RME DAC, then the Fosi ZH3 was also a nice headphone amp, with additional DAC features should you need them in future, such as usb input from a pc etc.

Thanks for your reply but I am looking for just a headphone amp that is perhaps better or not than the rme.

 

[totti1965]

Hey everyone!
I would like to try a headphone amp, and this model is of my interest to purchase.
Right now I use RME Fireface 802 MK1.
Do you think is worth the upgrade? Anyone tried this and can compare?
I have neumann ndh30 and beyerdynamic dt 770 pro 250 ohms.

Thanks!

In one word: Much smaller form factor - identical sound.

If you want real improvements for your set up, you have to add a parametrical Equalizer
and follow the tweaking suggestions of one of the specialized websites.

As an example:

PEQdB

The solution to audio.

peqdb.com

Graph Database – In-Ear Fidelity

Comparison Tools Databases

crinacle.com

So that your headphones at least can follow roughly the harman2019 Target curve (or the PEQdB Diamond target curve, which is a bit more airy).

Many newer DAC includes the possibility to do some Parametric EQ adjustments.

 

[toumpouris]

In one word: Much smaller form factor - identical sound.

If you want real improvements for your set up, you have to add a parametrical Equalizer
and follow the tweaking suggestions of one of the specialized websites.

As an example:

PEQdB

The solution to audio.

peqdb.com

Graph Database – In-Ear Fidelity

Comparison Tools Databases

crinacle.com

So that your headphones at least can follow roughly the harman2019 Target curve (or the PEQdB Diamond target curve, which is a bit more airy).

Many newer DAC includes the possibility to do some Parametric EQ adjustments.

thank you!

 

[davmol]

Thanks for your reply but I am looking for just a headphone amp that is perhaps better or not than the rme.

Edited to add more detail:

That's why I mentioned the ZH3 because it has an analogue RCA input, which bypasses the DAC and acts just like a headphone amp, but you get the dual function of having a dac for repurposing in future. You also retain tone controls on the analogue circuit but they can also be bypassed if you want pure analogue. Plus the benefit of a remote control.

Anyway ZH3 sales pitch over! In respect of the A50III the build quality is a step above recent Topping models, and really is beautiful (to me) in that simple black CNC all-aluminium block. If you don't need the balanced TRS inputs on the back (switchable with rca, so can be useful if you have two sources) then the A50s is an even smaller form factor and with the same beautiful all metal build, and if I recall, the same power outputs (I owned both in the past). The III is a bit more flexible with three headphone gain settings (-12/0/+12) vs the two (0/+6) on the s. Other than that I think you get a trigger input on the III and not on the s. Lastly, if you're into adding linear power supplies (I'm not) then also worth noting that the P50 matching power supply is sized to match the s models and not the III models.

Overall then if you want the smallest form factor and don't need balanced input or 12v trigger, then take the A50s, but if you want those features take the A50III, and if you don't care about those features or the size then get whatever is cheapest - note that the used prices can be quite good on these models - maybe people overlook them because they see them as old / outdated?

 

[totti1965]

@everyone: I don´ t have the problem, because as an "audiophile" music lover I am using roon - so my music management and streaming software has the option of perfect parametric equalizing or even incorporating convolving files.

But - for those who don´t want to spend US $850 livetime:

Is there an overview over every DAC and Preamplifier / Headphone Amplifier which has (digital) parametric equalization on board?

 

[JOCoin]

@everyone: I don´ t have the problem, because as an "audiophile" music lover I am using roon - so my music management and streaming software has the option of perfect parametric equalizing or even incorporating convolving files.

But - for those who don´t want to spend US $850 livetime:

Is there an overview over every DAC and Preamplifier / Headphone Amplifier which has (digital) parametric equalization on board?

Topping DX5 ii or DX1 ii both have PEQ. The DX5 ii even has dsp crossfeed. I've had a DX5 ii since launch and it's been problem free for me.