This is a review and detailed measurements of Topping L70 balanced headphone amplifier. It was sent to me by the company and costs US $349.

The L70 has the beautiful white segmented display. It is the most visible/high contrast display I have seen on an audio product. Volume control is very responsive and is relay based to provide perfect channel matching. You get both unbalanced and balanced output with the latter providing substantially more power. A remote control is provided. Back panel shows some nice extra features:

You have 12 volt trigger to power it on or have its power switch power other gear. A ground lift is provided as well to help with ground loops. And my favorite feature which is an included power supply.

A microprocessor controls the conditions of the unit and shuts it off or limits output as needed. Different error messages in the form of “r-” are provided when this happens. I pushed the unit routinely and repeatedly into clipping and overload with no ill effect. But please note that both headphone and power amps are subject to failures due to varying load/usage so if you are risk averse, you may want to wait for others to test it before deciding on purchasing it.

Topping L70 Balanced Measurements
I hooked up the L70 using its XLR input and measured its XLR balanced headphone output. In the next section you will see unbalanced performance. Let’s start with our dashboard:

I was amazed to see distortion at incredibly low -145 dB! This is some 30 dB better than our best case hearing threshold! SINAD which sums noise and distortion is noise limited to the tune of 120.4 which lands the L70 near the top of our rankings:

Speaking of noise, that is also excellent:

50 millivolt rating is excellent and the only thing keeping it from topping the charts completely is the fact that there is no negative gain setting:

Still, 93 dB is superb meaning that you almost get the dynamic range of the CD even though you are listening at just 0.05 volts!

Frequency response is as flat as we need:

The low distortion shows off again in multitone test:

After noise, power is everything in a headphone amp so let’s see how the L70 does with its XLR output:

I like to see > 100 milliwatts and the L70 accomplishes that in Low Gain!!! In high gain, it blows the doors open with 1 watt of power. This should let it drive high impedance with ease.

The dynamics get even better with 32 ohm:

We get a stunning 7 watts in high gain now! Even in low gain we have nearly 2 watts. And it does this while keeping its composure and not even clipping.

Changing the load we get the same superb results:

Topping L70 Unbalanced Measurements
Changing the output to 1/4 inch gets us the same superb dashboard:

Power is naturally low but still very healthy:

Topping L70 Listening Tests
I started testing with my Dan Clark Expanse headphone using XLR connection. This is a low impedance and insensitive headphone which breaks the back of many headphone amplifiers. Not here. The L70 dominated it like nobody’s business. In high gain, I did not dare to get anywhere near the max volume. There was so much power that it drove the right channel of the headphone into crackling with bass notes. Mind you, this was *at extremely* high volume level. Way past threshold of comfort. Yet, the L70 had more power left on the volume control! The sound and overall experience was exceptional with super detail and dynamics.

I then switched to Sennheiser HD650 which is easier to drive. The sound was yet again superb with some 30 dB of headroom left on L70. If I didn’t have to finish the review by taking a picture of the L70, I would still be sitting there listening to this combo! Even though the HD650 is deficient in bass you would not know it while driving it with L70. The sound was superbly clean and enjoyable.

Conclusions
As much as Topping has made us expect superb engineering, I am still surprised when I unbox and measure/experience their newer offerings. The L70 innovates with wonderful new front panel and incredible power and low noise and distortion. It has level of performance that enables you to buy and enjoy any headphone regardless of insensitive or difficult it is to drive. Nice features like R2R relay control solves the problem of analog volume controls causing channel mismatch, giving you a perfect experience even with sensitive IEMs/headphones. I like to find something to complain about I just can’t!

It is my pleasure to recommend Topping L70 headphone amplifier.

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