This is a review and detailed measurements of the Topping DX3 Pro+ DAC and headphone amplifier. It is a replacement for one of my most favorite combo products, the DX3 Pro. It was sent to me by the company and costs US $199.
The DX3 Pro+ maintains the gorgeous and high contrast orange LEDs which I am very fond of:
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The back panel is a bit unusual in a good way with sporting dual Coax inputs:
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There is a remote and support for Bluetooth. The external power supply is a 15 volt one which should help with power output of the headphone amplifier.
Topping DX3 Pro+ Measurements
Let's start with our DAC measurements and the dashboard:
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I expect great performance from Topping and the DX3 Pro+ naturally delivers. Distortion products are at -125 dB worst case which is well below threshold of audibility. THD+N sums to 0.000146 which matches company spec of 0.00015 rating of the company. Converting that to dB, we get our SINAD which comfortably lands in our top tier of all DACs tested:
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Zooming into its neighbors:
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Dynamic range is excellent:
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Multitone test shows again the low level of distortion no matter how many tones we throw at it:
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Intermodulation distortion shows that it matches its older brother and then beats it at highest output levels:
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The graph never tilts up indicating that it is noise limited, not distortion.
Jitter test shows a bit of interference below 1 kHz which fortunately is completely inaudible:
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Linearity is nailed showing excellent accuracy of levels:
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A bunch of filters are available for you to play with as usual:
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THD+N vs frequency naturally varies with the filter you use:
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Headphone Amplifier Measurements
Let's start with our signal to noise ratio with headphone out:
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I was hoping for a little bit better performance at 50 mv output although what is there is clearly above average:
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Most important test here is power output:
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There is plenty of power and no clipping/rise in distortion.
Switching to 32 ohm load, we still have good bit of power:
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Testing at many load impedances tells us that the amp doesn't like very low impedances:
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This was a good test of the microprocessor controlled protection circuit which kicked in at the lowest impedances. This had been a sore point with the older DX3 Pro and Topping has gone aggressive with active monitoring here.
Topping DX3 Pro+ Listening Tests
I performed all of my testing in high gain and there, the DX3 Pro+ had no trouble bringing out the best fidelity in both Sennheiser HD650 and Drop Ether CX. It drove them with authority, creating a dynamic response with tons of detail and superb tonality. Anyone who thinks these superbly low noise and distortion audio products sound "clinical," should check themselves into a clinic!
For grins, I also drive my Dan Clark Stealth headphone. Here, there was less power than when using the above to headphones but still very usable. Note however that when I cranked up the volume to 0 dB for testing, the amp went into protection. I tried it again but could not duplicate it. Regardless, it was pretty good before it hit that limit anyway.
Conclusions
Prior to this review, I was getting depressed testing product after product with awful performance. Results were so bad that I was starting to doubt my Audio Precision analyzer! Fortunately I had the DX3 Pro+ to test which as you see, not only performed superbly, it also vindicated the audio analyzer!

This combo unit gives you everything you need in a compact and attractive unit at excellent price. It doesn't have infinite capability as far as low impedance headphones are concerned so for that, you need to step up to myriad of other options from Topping. Outside of that niche use though, the DX3 Pro+ does the job and does it superbly.
I am happy to recommend the Topping DX3Pro+.
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