Topping A30Pro Review (Balanced Headphone Amp)

[Giangi71]

Yeah I know. That doesn't mean that in this particular case the TRS output secretly is the same as the XLR input and could be used instead when one only has 6.3mm TRS balanced connectors despite the sockets being marked as 'output'. In THIS particular case.
But agreed it would (and does) confuse people...

However better 2xlr 2xlr

 

[ShiZo]

A bit tired of Topping.

Kinda like people get tired of tom brady for constantly winning?

 

[JIW]

@amirm would it be possible to measure the D30 Pro + A30 Pro combo? So the full chain with input to the DAC and to the output of the amp?

Since SINAD for both is dominated by noise, assuming the noise is uncorrelated, some educated guesses can be made with some simple calculations.

For the DAC set to 0.0 dB and the amplifier at full volume in medium gain - 0.9804x, i.e. -0.172 dB - using symmetrical XLR connection gives a combined SINAD of 117.245 dB at 4.062 V RMS. The main difference would thus be a 3-4 dB increase in noise using medium gain. For low gain - -14 dB -, the noise of the amplifier should dominate, giving an increase in noise of about 0.2 dB assuming the amplifier's noise level is the same in low gain as in medium gain for a SINAD essentially that of the amplifier alone. For high gain - 14 dB -, the noise of the DAC gets amplified by 14 dB and should dominate, giving an increase in noise of about 15 dB. However, since maximum output level is 10-12 dB above 4 V, SINAD is at maximum power is degraded by 3-5 dB so still at least around 115 dB.

 

[Inkey31]

This is a review and detailed measurements of the Topping A30Pro balanced input and output headphone amplifier and pre-amp. It was kindly sent to me by the company. I am sorry but I don't have release date or pricing. I usually only get finished products from Topping so expect release date to be soon (post Chinese new year).

The A30Pro is the heftiest and most serious looking enclosure from Topping with its manly venting holes on top:
View attachment 112407

Some of the weight is due to inclusion of mains power supply in the case which I appreciated:

View attachment 112408

We see some other changes here. Pre-amp balanced out is quarter inch jacks due to smaller enclosure. And there is a ground lift which should help people who run into nasty ground loops.

In use the unit got a bit warm but nothing remotely serious. Sitting there by itself, it warms up to a bit above ambient temperature.

NOTE: there is no pre-amp functionality here. The rear connectors are pass through for convenience. Also, the output is only unbalanced and connectors are there for convenience, not more power.

Topping A30Pro Measurements
As usual, we start with our dashboard of unity gain (4 volts in, 4 volts out) using XLR in and unbalanced 1/4 headphone out:

View attachment 112409

Performance is superb as one expects going into a test of Topping product. SINAD with is the sum of noise+distortion relative to our 1 kHz tone is essentially as good as it gets:

View attachment 112410

Signal to noise ration both at unity gain and 50 mv are exceptional:
View attachment 112424


The latter is now class leading:
View attachment 112412

Think about it: you are getting the full dynamic range of 16 bit music when outputting just 50 millivolts! This is one quiet headphone amp considering that some of this noise is from my analyzer! You can comfortably use the A30Pro with any sensitive IEM or headphone with zero worry about background hiss or noise.

Frequency response is excellent of course:
View attachment 112413

Let's measure power relative to noise+distortion with unbalanced load of 300 ohm:
View attachment 112425

Oh wow! 0.73 watts using such a high impedance? This is wonderful as it means you don't need to use balanced connections to get enough power to drive high impedance and inefficient headphones. Low and medium gains have identical performance and incredibly low noise floor with no clipping. So if you hear distortion there, it is in your music.

Switching to the other extreme of 32 ohm, we see the same picture:
View attachment 112415

This is 5.5 watts times two! This little box is producing 11 watts of power!!! I don't think we have ever measured an amplifier this powerful forgetting about how low noise and distortion it is.

Switching to balanced mode, we don't get much more power as there is no need for more:
View attachment 112418

For 50 ohm, I thought I show Topping A90 as a reference:

View attachment 112417

Notice how the noise level is even lower although A90 pulls ahead with a bit more power before clipping.

Finally, channel matching is quite good although as noted, there will be unit to unit variations:
View attachment 112419

The low gain mode though (which is less than 0 dB) should help keep the volume control in its more accurate range if you do run into a sample with worse performance.

Topping A30Pro Listening Tests
I started with my usual Ether CX 25 ohm headphone with balanced connection. The A30Pro had no trouble driving this headphone with incredible power and authority with zero sign of strain or distortion.

Switching to Sennheiser HD650 showed amazing detail, dynamic range and superb bass handling. I am usually brave enough to turn the volume to max for a second or two to see if the amp distorts or not. Not here. By the time I got to 3:00 o'clock, and staying there for half a second, I knew I had to back down and in a hurry! Wow, did that get loud! Even I couldn't handle that much power. There is so much extra headroom here for any headphone you want to throw at this amplifier.

Conclusions
Just when we thought we had reached a plateau with performance of headphone amps, Topping pushes a bit more in the form of lower noise and much more power in unbalanced mode. A solid and nice looking enclosure completes the picture for one of the most ideal headphone amplifiers I have laid may hands on. The medium sized enclosure with built-in power supply is definitely worth the extra cost to get rid of the dongle of the lower end products in view.

It goes without saying that it is my absolute pleasure to recommend Topping A30Pro headphone amplifier.

Note: this is a new headphone amplifier and while I have not found any issues in in my testing, there can be problems. If you are risk averse, you may want to let others buy and use it before jumping in to purchase one. My focus in these reviews is engineering performance, not reliability.

EDIT: Video review is also up now:

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As always, questions, comments, recommendations, etc. are welcome.

Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Holy shit is that Amir? Anyone else picture him differently? In my head I thought Gandalf, in reality he is looks like Amir.

 

[wakakaakaka]

And before anyone ask, the chassis is always earthed. And there are back to back diodes across the switch to make sure under extreme condition the device is still good.

Also to reproduce ground loop issue:
D10s powered by desktop PC - RCA - A30pro
And switching to LIFT eliminates the ground loop.

I got the A90, it does not have such a Ground<->Lift-feature. Why? It costs more.

PC-> USB cable > DAC -> topping A90 -> headphone. DAC and amp connected via RCA and headphone is 6,5 mm single ended.
I got noise problems due to the graphics card in the computer. The more heavy utilized the graphics card is (up to 300+ W), the more I hear the noise on the headphone. Playing games at normal listening level, the noise coming out of the headphone is audible; it is high pitched and varied depending on the graphic card load.
Switching to A90 to High gain makes it even louder. Turning the A90 to high gain and volume to the max. (without playing any sound, a faint hiss is hearable. That shouldn't be the case I guess (no black background)?
How to solve that without such nifty ground-switch from the A30pro?

Also, is the A30pro truly balanced via XLR (as the A90, with double the circuitry), or a differential amplifier?

Question: What was the formula of calculating output power at a specific resistance, 58 ohms for example.
Thanks!

 

[KTN46]

I am so excited to hear the pricing... I wonder if all the praise Amir had for it gave topping a few ideas about its MSRP...

 

[Vini darko]

I got the A90, it does not have such a Ground<->Lift-feature. Why? It costs more.

PC-> USB cable > DAC -> topping A90 -> headphone. DAC and amp connected via RCA and headphone is 6,5 mm single ended.
I got noise problems due to the graphics card in the computer. The more heavy utilized the graphics card is (up to 300+ W), the more I hear the noise on the headphone. Playing games at normal listening level, the noise coming out of the headphone is audible; it is high pitched and varied depending on the graphic card load.
Switching to A90 to High gain makes it even louder. Turning the A90 to high gain and volume to the max. (without playing any sound, a faint hiss is hearable. That shouldn't be the case I guess (no black background)?
How to solve that without such nifty ground-switch from the A30pro?

Also, is the A30pro truly balanced via XLR (as the A90, with double the circuitry), or a differential amplifier?

Question: What was the formula of calculating output power at a specific resistance, 58 ohms for example.
Thanks!

The a90 is simply amplifing incoming signal warts and all. The problem is between the pc and dac most likely. Are you able to try toslink with the sound card and dac?

 

[SaberCat]

I consider them some of the most ethical companies that I have worked with. I concur,unlike Ifi With that defective Hip Dac that drain power even when shut off,Ifi won't answer that question,just put a byline in the manual 12hr down to 8 hr,doesn't even last for 5 hours,at least Topping acknowledged their fault,I have much respect for John Yang and company.

I fully concur - the speed and diligence with which they first acknowledged the ESD design flaw with the L30 amp, then rectified by shipping replacements to all customers, is a sign of a company that wants to put their reputation up there with any "big name" player. I would have no hesitation buying any Topping product because they stand behind what they sell, and their presence online here to transparently discuss the details of their designs is great for all of us, and moves the hobby forward in a way the snake oil peddlers never will.

 

[Audioent]

Which is better? Topping A90 or Topping A30 Pro? Thanks

 

[Veri]

Which is better? Topping A90 or Topping A30 Pro? Thanks

A90 has higher output still when using with balanced headphones and its balanced 4.4mm/XLR output.
A30 has lower but still very high single-ended output levels on all its outputs when used with balanced DAC.

To clarify in a simple way:
A30P single ended in single ended out = medium power output
A30P balanced in single ended out = high power output
A30P balanced out = same as single ended output
A90 single ended in single ended out = medium power output
A90 single ended in balanced out = high power output
A90 balanced in single ended out = high power output
A90 balanced in balanced out = highest power output

Balanced, due two amp modules will have higher theoretical noise though, but should be no issue since it's still low. But A30 Pro is single ended only, so very low levels of noise across the line, with damn powerful output; and can play with the grounding switch in case of ground loop/hum, something the A90 does not have.

 

[riffmaker]

Do you think it makes any sense to buy A30Pro or A90 if I have RME ADI-2 DAC FS?

 

[jannek]

Do you think it makes any sense to buy A30Pro or A90 if I have RME ADI-2 DAC FS?

For another room, maybe.

 

[solderdude]

A30P single ended in single ended out = medium power output
A30P balanced in single ended out = high power output
A30P balanced out = same as single ended output

A30pro can deliver the same power output regardless of inputs used.
Of course for SE input you need double the input voltage to go equally loud.
A30P does not have balanced out. It has a connector that lets you connect balanced cables but the actual signal is SE (both - wires tied together to ground)

 

[A Surfer]

The convenience balanced headphone input of the A30 Pro is a smart addition I think. I had a Yulong headphone amp that had this feature as well.

 

[Veri]

A30P does not have balanced out. It has a connector that lets you connect balanced cables but the actual signal is SE (both - wires tied together to ground)

Well yes, okay, it has a "balanced output" connector, which isn't actually differential. I thought that was clear, haha

 

[solderdude]

The convenience balanced headphone input of the A30 Pro is a smart addition I think

It's a bit like the Geshelli Archel 2.5 pro but this one performs better, has higher power output, multiple gain settings (2.5Pro also), all metal enclosure (grounded for those that wonder) and also has through-put.
It also has 2 select-able inputs (2.5Pro as well) and 3 different headphone connectors for convenience.

 

[Atanasi]

The convenience balanced headphone input of the A30 Pro is a smart addition I think. I had a Yulong headphone amp that had this feature as well.

Technically, separate grounds improve crosstalk. XLR has smaller contact resistance and should glitch less compared to jacks if it is hotplugged.

 

[jawbfl]

Technically, separate grounds improve crosstalk. XLR has smaller contact resistance and should glitch less compared to jacks if it is hotplugged.

This trend of 4-pin XLR & 4.4 outputs when it's not a balanced output is bad IMO, it's a bit misleading because you have to ask so many questions now and this thread is the best argument, amps are now amp+adapters box because having too many ports looks more "high-end" thus can be sold for more.

Why not have the minimal amount of ports and let the user buy adapters as needed instead of charging him for those beforehand? I'm not accusing Topping of anything bad just complaining about this trend, heck some manufacturers even make larger PCBs and cases than needed, some put weights to feel hefty etc those are more shady.

 

[respice finem]

Do you think it makes any sense to buy A30Pro or A90 if I have RME ADI-2 DAC FS?

In this case, not really. With the RME you have a DAC/HPA/preamp.

 

[solderdude]

This trend of 4-pin XLR & 4.4 outputs when it's not a balanced output is bad IMO, it's a bit misleading because you have to ask so many questions now and this thread is the best argument, amps are now amp+adapters box because having too many ports looks more "high-end" thus can be sold for more.

It's convenient and the important issues as to why one would want to use a balanced cable/headphone are solved just as well as when a real balanced amp were used. Topping is not the only one using SE outputs on balanced connectors instead of fully balanced.
1: There is no common return wire
2: Output voltage (and gain) are higher than most other SE amps.
3: No converters needed, just plug and play. One could say it is missing a 2.5mm TRRS connector ....