Topping LA90 Review (Integrated Amplifier)

[simplywyn]

Well, we need to have the specs and do the math ... are you using it balanced or unbalanced?

Freya output impedance is 75 ohms unbalanced and 600 ohms balanced. In passive mode there's no gain and with gain we have 12 dB. We need also the output voltage in the source (streamer, CD player, etc.).

In the other side we need to know the specifications in the amplifier input buffer, there're many. As an example I checked one version in Apollon Audio:
Input sensitivity 2.52 V (that means with 2.52V you're getting the max output ... )
47k input impedance

And so on ... But that kind of stuff must be checked... That's why many times the pre and power amp of the same brand works better together

The entire chain:

Denafrips Ares II
Freya S+ Tubes
VTV 1ET400 EVAL1

Everything is balanced

It looks like there is enough difference for it not to be

 

[mike70]

The entire chain:

Denafrips Ares II
Freya S+ Tubes
VTV 1ET400 EVAL1

Everything is balanced

It looks like there is enough difference for it not to be

Well, denafrips ares 2 is 4V on balanced output. That's a big amount of voltage.

Freya in passive mode at half potentiometer is almost the power amp at max volume in the pre buffer I mentioned before. With gain mode ... way before than that.

I don't have the gain / input sensitivity on that Vtv implementation, but gain mismatch/ distortion is always a factor between power amps.

 

[simplywyn]

The VTV is literally the EVAL1: https://purifi-audio.com/eigentakt/eval1/

 

[mike70]

The VTV is literally the EVAL1: https://purifi-audio.com/eigentakt/eval1/

You can setup many options about gain and buffer preamp in the EVAL1

 

[simplywyn]

You can setup many options about gain and buffer preamp in the EVAL1

Oh you can? I guess I can tweak it myself then, what's the most optimal setup?

 

[staticV3]

what's the most optimal setup?

leaving the buffer out altogether, but you need a DAC that can drive the low Zin and that can provide high enough voltage.

 

[simplywyn]

leaving the buffer out altogether, but you need a DAC that can drive the low Zin and that can provide high enough voltage.

It's a VTV EVAL1, how do I go about removing the buffer?

 

[staticV3]

It's a VTV EVAL1, how do I go about removing the buffer?

 

[simplywyn]

very nice thanks, should I bypass in this case?

 

[staticV3]

very nice thanks, should I bypass in this case?

you need a DAC/preamp that can drive a 2-4kΩ load and can output close to 10Vrms. If you have that, then I think it's worth experimenting with bypassing the input buffer.

 

[simplywyn]

you need a DAC/preamp that can drive a 2-4kΩ load and can output close to 10Vrms. If you have that, then I think it's worth experimenting with bypassing the input buffer.

I have a Freya S + Denafrips Ares II, is that good enough?

I just took apart the VTV, pretty awesome... I can probably build my own next time..

 

[staticV3]

I have a Freya S + Denafrips Ares II, is that good enough?

Both the Freya S and Ares II have pretty high output impedance, and so aren't that suited to this use case. I'd leave the buffer enabled.

 

[pepie34]

Just a note on the fact that the amplifier seems cooler (getting less hot) after the V1.3 update
I think I don't like amp with microchip...I'm pretty sure a doom hack will come one day on the LA90

 

[simplywyn]

Anyone know the proper steps to updating LA90? Unplugged it, plugged in USBC (Do I plug this amp back in?) nothing happening

 

[pepie34]

See my previous post:

It can be done on MS Windows only (not MacOS as stated in the firmware update doc) and the cable need to be (usb a <-> usb c) not (usb c <-> usb c).

1. unplug everything including the power cable (very important) wait for a minute or two
2. plug the device with a USBA to USBC cable to a windows computer (still with the power cord not connected)
3. it appears as a mass storage device
4. a text file in the new drive gives you the current version of the firmware
5. you drop the firmware update file on the drive
6. the drive ejects itself
7. the drive reconnect and a new text file tells you that the update went ok

It does not work on linux or Mac or with a pure USB-C Cable

 

[simplywyn]

See my previous post:

It can be done on MS Windows only (not MacOS as stated in the firmware update doc) and the cable need to be (usb a <-> usb c) not (usb c <-> usb c).

1. unplug everything including the power cable (very important) wait for a minute or two
2. plug the device with a USBA to USBC cable to a windows computer (still with the power cord not connected)
3. it appears as a mass storage device
4. a text file in the new drive gives you the current version of the firmware
5. you drop the firmware update file on the drive
6. the drive ejects itself
7. the drive reconnect and a new text file tells you that the update went ok

It does not work on linux or Mac or with a pure USB-C Cable

Crazy how this isn't posted anywhere but on forums lol

 

[xaxxon]

Compared to the PA5, I guess it’s just for those that want the bragging rights, otherwise I‘d go PA5.

make sure you look at the reliability issues with the pa5. Mine lasted 5 months before it popped. Lots of people having problems with them.

 

[IPunchCholla]

make sure you look at the reliability issues with the pa5. Mine lasted 5 months before it popped. Lots of people having problems with them.

Good advice. At this point I am shocked mine is still working (knock on wood).

 

[Aaron7]

Maybe the last attempt, as it is hopeless. Lowest SINAD tells nothing about stability and tend to oscillations especially with complex load, nothing about abilities to drive complex load with high +/- phase angle deviations, nothing about current output. Though the ultra low SINAD brings nothing in audibility and sound quality, all the features that I have mentioned do. Even worse, high FB needed to get lowest SINAD means more tendency to instability.

I am running Topping LA90 in Bridged Mono mode. It is powering Focal Kanta 2 stand mount and center loudspeakers. It replaced my much more powerful ATI527NC. There is NO comparison. The ATI sounds Dirty and harsh compared to the Topping. Hence, improved distortion specs of 16db were way more significant than an extra 110 watts per channel.

 

[Aaron7]

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.
View attachment 202305
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:

View attachment 202306

While quite solid, you can pick it up with one hand. The small size is aided by a massive external switching power supply:
View attachment 202307

Here are its ratings:
View attachment 202309

Back to the unit, you can see three balanced inputs. Volume control can be bypassed although I did not do so for my testing. You can also operate LA90 in bridged mono mode. There is also 12 volt trigger.

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:


View attachment 202314

I don't need to tell you that this is a stunning level of achievement. We have a power amplifier producing almost the same SINAD as a state of the art DAC! Using this number, LA90 grabs the top spot with ease with a nice gap to boot:

View attachment 202315

Here it is zoomed:
View attachment 202319
You might be thinking that it can only do so with low gain but that is not true. Even in high gain performance is spectacular:

View attachment 202317

It would still achieve top spot in our rankings and achieve full audible transparency.

Not only is distortion vanishingly low, so is noise level:
View attachment 202320

View attachment 202321

Frequency response is flat and wide as expected:
View attachment 202323

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:

View attachment 202324

Multitone test shows the very low distortion levels:

View attachment 202325

Let's see how much power we have:
View attachment 202326

So power is modest in non-bridged mode. But note how good the high gain mode is so I would feel just fine using that for operation of the unit if you need to. Allowing distortion to rise to 1% naturally gets us more power:

View attachment 202328

Here is 8 ohm:

View attachment 202329

Oops. "High Power" should be "High Gain."

Changing frequencies shows the same excellent performance:
View attachment 202331

Despite being pushed deep into clipping, the amplifier did not complain until I got to 20 Hz where its over temperature shut it down.

Finally, you don't need any warm up:
View attachment 202332

Topping LA90 Bridged Mode Performance
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:

View attachment 202333

Performance is still exceptional. Here is our SNR:
View attachment 202334

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):
View attachment 202335

Now we get good bit of power at 95 watts with almost no penalty relative to non-bridged mode. Notice the massive gap as far as noise floor relative to Purifi amplifier.

Allowing for 1% distortion we get:
View attachment 202336

Here is the super wideband spectrum of the amplifier while producing 5 watts:

View attachment 202338

Edit:
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:

View attachment 202703

Let's now sweep the power:
View attachment 202704

You don't get extra power relative to 4 ohm but the amplifier was stable and did not even go into protection.

Now let's switch to Bridged mode (both amplifiers driven in differential mono) and run our power sweep again:
View attachment 202706

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.

Conclusions
It 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!

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

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Great review Amirm. As a result of seeing this review, I bought 3 LA90 for my 3 front Focal Kanta 2 speakers. I am running them in bridged mode with high gain. They are a lot cleaner than my ATI527NC which you reviewed—it was not even in the same ballpark. The ATI you measured at 99 while the LA90 at 120. I am surprised how dirty sounding the ATI sounds in comparison. That hash between 99db and 120 removed the richness of the music.