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Topping A30Pro Review (Balanced Headphone Amp)

amirm

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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).

EDIT: I just heard back from Topping. As of this writing (March 1, 2021), the cost is US $349.99.

The A30Pro is the heftiest and most serious looking enclosure from Topping with its manly venting holes on top:
Topping A30Pro Review Balanced High-end Headphone Amplifier.jpg


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

Topping A30Pro Review Balanced High-end Headphone Amplifier pre-amplifier.jpg


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:

Topping A30Pro Measurements XLR In Unblanaced Out.png


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:

best headphone amplifier balanced review.png


Signal to noise ration both at unity gain and 50 mv are exceptional:
Topping A30Pro Measurements SNR XLR In Unblanaced Out.png



The latter is now class leading:
Most quiet hiss headphone amp review.png


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:
Topping A30Pro Measurements frequency response XLR In Unblanaced Out.png


Let's measure power relative to noise+distortion with unbalanced load of 300 ohm:
Topping A30Pro Measurements Power into 300 ohm XLR In Unblanaced Out.png


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:
Topping A30Pro Measurements Power into 32 ohm XLR In Unblanaced Out.png


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:
Topping A30Pro Measurements Power into 300 ohm XLR In Blanaced Out.png


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

Topping A30Pro Measurements Power into 50 ohm XLR In Blanaced Out.png


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:
Topping A30Pro Measurements Channel Balance  XLR In Blanaced Out.png


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/
 
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Also the signal to noise ratio graph and distortion vs power @ 300 ohm unbalanced. Not in a good day aye.:D
 
The front panel jacks are xlr, 1/4” and what? Is it an 4.4mm?
 
@amirm have you tried connecting these to your Salons?
 
My wallet saw this thread before my brain processed the title.
When I saw and click on this thread, I mistook it for the D30Pro thread. When the thread opened, I saw it led me to the 1st page and I was confused at first. Where was the usual continuation page...then I realized this was a new thread, the A30Pro. Oh goody :cool:
 
Did some quick calcs for the unbalanced HP out:

300ohm @ 0.73W
14.8V
0.049A

33ohm @ 5.5W
13.5V
0.41A
In comparison my ASUS ROG Z370E motherboard headphone amplifer is rated +/-50mA max.
Ti RC4580 -2.png

Ti RC4580.png
 
Would be interesting why to choose this over a L30. Integrated power supply? Look and feel? Balanced connections?
THD+N and SINAD are almost identical and considering power: is there any headphone so unsensitive to need that much?
 
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There are rumors of HE6 needing plenty of power, but I'm not sure anyone confirmed that scientifically.
 
FYI video review is up. I fixed the audio issue but sadly goofed and forgot to change the text inside the review as to the title. Oh well. Added it to the review and here is a copy as well:

 
Excellent review! Just noticed this. The watermark in the lower lefthand corner of the video says “AudioSciecneReview.com.”
 
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