Note: This article is based upon the video "Topping LA90 Review (Integrated Amplifier)" made by Amir Majidmehr on Audio Science Review and is printed here in partnership with Audio Science Review. The review was originally posted on April 25th, 2022. It has been reproduced here in its entirety. You can purchase the TOPPING LA90 on Apos Audio.
This is a review and detailed measurements of the Topping LA90 integrated amplifier. It was sent to me by the company and costs US $800.
I must say, this is one interesting industrial design. Everything oozes style despite the diminutive package. This aspect continues in the operation of the unit with the sound of the relays solidly clicking indicating something good is going to happen.
Here is the side view:
While quite solid, you can pick it up with one hand. The small size is aided by a massive external switching power supply:
There are to gain settings. One at 10 dB and another at 20 dB (nominal).
Topping LA90 Measurements
These are non-bridged mode measurements. Bridged setup follows this section. Let's start with our dashboard of 5 watts into 4 ohm in low gain mode:
It would still achieve top spot in our rankings and achieve full audible transparency.
Not only is distortion vanishingly low, so is noise level:
Being class AB design, it has no load dependency.
Crosstalk is incredibly good although it loses a tiny bit relative to last champ of amplifiers:
Changing frequencies shows the same excellent performance:
Finally, you don't need any warm up:
A shorting wire is provided to connect the two negative speaker bindings together allowing bridged mode from the top two posts. Here is our dashboard again:
Due to more power available now, we cross the amazing 140 dB SNR threshold. What this says is that even if you play at 140 dB, the noise level will be at or below threshold of hearing! Of course there is not enough power there to do that but basically you know that noise is not part of the equation with LA90 as even 5 watt measurement hits below threshold of hearing.
We want to know the power increase though so here it is (with 8 ohm which is the minimum impedance):
Allowing for 1% distortion we get:
Power Tests at 2 Ohm (Stereo) and 4 Ohm (Bridged)
Requests were made to test the amplifier beyond its minimum load impedance specs. Let's start with 2 ohm load while driving one channel in stereo mode. Dashboard still shows superb performance:
Now let's switch to Bridged mode (both amplifiers driven in differential mono) and run our power sweep again:
Now we see the amplifier "doubling down" producing nearly 200 watts into 4 ohm. Again, the amplifier was well composed and kept driving into clipping region without complaining, or shutting down.
Again, the above tests are beyond the amplifier specifications and tests I never run as such.
ConclusionsIt is clear that Topping engineers are bringing their expertise in designing ultra low noise and distortion in headphone amplification to power amplifiers. As such, they have outdone every amplifier I have measured in that regard, getting ahead to capture the #1 position with a large gap to #2 choice.
The amplifier is not for everyone though. Power level is modest as compared to competitors. And you have that large external power supply. My wish is another version of this amp with built-in power supply, motorized volume control with bridge mode standard. For now, we need to celebrate one of the most important development in delivering transparent, high fidelity amplification to audiophiles in a very attractive package.
It is my absolute pleasure to recommend the Topping LA90. History is made on this day folks!