Topping LA90 Discrete Amplifier Review

[Senegalas]

I own LA90 now. It's fine

 

[alanhuth]

Bump.

Is Topping going to address this problem with many LA90 Discretes popping and scratching? Their website doesn’t acknowledge the problem.

 

[vazakh]

Good day!
Due to my stupidity, I damaged the device, I downloaded the firmware from the topping website not for LA90 Discrete, but for A90 Discrete, followed the instructions and uploaded the firmware to the device, and now the amplifier does not work. Can you tell me what can be done, where can I get the firmware for LA90 Discrete?

 

[staticV3]

Good day!
Due to my stupidity, I damaged the device, I downloaded the firmware from the topping website not for LA90 Discrete, but for A90 Discrete, followed the instructions and uploaded the firmware to the device, and now the amplifier does not work. Can you tell me what can be done, where can I get the firmware for LA90 Discrete?

Topping have not yet published a firmware or firmware update for the LA90D, so the only way is to contact their customer support via [email protected]

 

[Toku]

Good day!
Due to my stupidity, I damaged the device, I downloaded the firmware from the topping website not for LA90 Discrete, but for A90 Discrete, followed the instructions and uploaded the firmware to the device, and now the amplifier does not work. Can you tell me what can be done, where can I get the firmware for LA90 Discrete?

Please contact Topping to obtain the LA90 Discrete firmware and perform the update procedure in the same way.

 

[WeekendWarrior]

There was a discussion here asking whether bridged LA90Ds would work for speakers that dipped to 3.4 ohms. Did this get resolved? I'm looking enviously at the AsciLab A6B, and my single LA90D won't cut it with these speakers, which dip to 3.4 ohms too. Buying a second LA90D and bridging them is cheaper than buying a new amp, hence my question.

And what about Amir measuring 279 watts @ 4 ohms when bridged, compared to Topping's 180 watts @ 4 ohms. Was that mystery ever solved?

 

[WeekendWarrior]

I've answered my own question, or at least Topping have as I asked them the same questions last night and got a reply this morning:

"Due to differences in testing conditions, please refer to our test report as the standard. An impedance of 3.4 ohms is not a problem — you can use it with confidence."

I presume the first part addresses the difference between Amir's and their measurements. The second part is self explanatory.

In the UK a LA90D is £600 so that would be the cheapest option. Alternatively I could sell or trade my existing LA90D and buy one of the new 1ET6525SA based 450 watts/channel class D Purifi amp for £1200 ish. Assuming £300 or so for my own LA90D, that'd be a cost to change of £900. Putting it like that, maybe ditching the LA90D for a Purifi is an option still worth considering.

 

[vazakh]

I wonder if it is possible to use LA90D in mono mode in tandem with B200

 

[staticV3]

I wonder if it is possible to use LA90D in mono mode in tandem with B200

WDYM by tandem? LA90 driving the left speaker and B200 the right?

 

[vazakh]

LA90 управляет левым динамиком, а B200 — правым?

Yes, that's right.

 

[staticV3]

Yes, that's right.

It's possible and perfectly safe, but be aware that the LA90D in Mono and the B200 do not have the same gain.

Unless you compensate for the difference in gain einter upstream of the Amps, or using the LA90D's volume knob, one speaker side will always play louder than the other.

You can use a basic multimeter and 60Hz test tone to ensure that both sides play equally loud.

 

[vazakh]

It's possible and perfectly safe, but be aware that the LA90D in Mono and the B200 do not have the same gain.

The difference in power can be leveled out by adjusting the balance?

 

[staticV3]

The difference in power can be leveled out by adjusting the balance?

Power dictates headroom
Gain dictates loudness

Adjusting the individual channel volume cannot change the Amp's headroom of course.

But it can equalize the difference in gain, so that both speakers will play at the same volume.

 

[Le_Passager]

Dear mates! I`m glad to welcome all members of this great place. I have been in the "read only" mode for a long time, but now I want to ask some question. I apologize in advance for my bad English.

I recently started using a Topping stack: DAC, preamp, power amplifier (LA90 D). I used it on desktop acoustics, everything worked great.

But now I am planning to install floor speakers DA Baltus 90. Their impedance is 4-8 ohms. The required amplifier power is indicated from 100 to 200 W. Therefore, I bought another LA90 D, to use both in mono mode.

According to the indicators, everything seems to match. But I am interested in real experience. Does anyone use LA90 D with heavy floor speakers?
Is there a measured value of the damping factor for LA90 D in mono mode somewhere?
Isn't the use of LA90 D a "bottleneck" in a system with heavy speakers, which can lead to damage to equipment, such as tweeters?
I read that a low-power amplifier is worse than an amplifier with excessive power.

 

[staticV3]

Hi @Le_Passager! Welcome to ASR.

Is there a measured value of the damping factor for LA90 D in mono mode somewhere?

The LA90D has a specified output impedance of <5mΩ in Mono mode:


Hence, damping factor is 4/0.005=800 or better at 4Ω and 8/0.005=1600 or better at 8Ω.

Isn't the use of LA90 D a "bottleneck" in a system with heavy speakers, which can lead to damage to equipment, such as tweeters?
I read that a low-power amplifier is worse than an amplifier with excessive power.

The LA90D in Mono mode can put out 280W at 4Ω:


Since the DA Baltus 90's required amplifier power is indicated from 100 to 200 W, the LA90D Mono is an amplifier with excessive power.

You have nothing to worry about regarding bottlenecking or tweeter damage.

 

[manisandher]

The LA90D in Mono mode can put out 280W at 4Ω:

Interestingly, this is 100W higher than Topping's own measurement.

 

[Le_Passager]

You have nothing to worry

Thank you very much for the detailed answer! I tried to read this thread and look for information inside. But you gave all the necessary information at once.

 

[Senegalas]

Dear mates! I`m glad to welcome all members of this great place. I have been in the "read only" mode for a long time, but now I want to ask some question. I apologize in advance for my bad English.

I recently started using a Topping stack: DAC, preamp, power amplifier (LA90 D). I used it on desktop acoustics, everything worked great.

But now I am planning to install floor speakers DA Baltus 90. Their impedance is 4-8 ohms. The required amplifier power is indicated from 100 to 200 W. Therefore, I bought another LA90 D, to use both in mono mode.

According to the indicators, everything seems to match. But I am interested in real experience. Does anyone use LA90 D with heavy floor speakers?
Is there a measured value of the damping factor for LA90 D in mono mode somewhere?
Isn't the use of LA90 D a "bottleneck" in a system with heavy speakers, which can lead to damage to equipment, such as tweeters?
I read that a low-power amplifier is worse than an amplifier with excessive power.

You will be fine with single one. I have Golden ear Triton fives and I run amp on low gain, basically with music never have to go above 2PM, with games I can max it out but usually don't need to.

 

[Dottie]

Dear mates! I`m glad to welcome all members of this great place. I have been in the "read only" mode for a long time, but now I want to ask some question. I apologize in advance for my bad English.

I recently started using a Topping stack: DAC, preamp, power amplifier (LA90 D). I used it on desktop acoustics, everything worked great.

But now I am planning to install floor speakers DA Baltus 90. Their impedance is 4-8 ohms. The required amplifier power is indicated from 100 to 200 W. Therefore, I bought another LA90 D, to use both in mono mode.

According to the indicators, everything seems to match. But I am interested in real experience. Does anyone use LA90 D with heavy floor speakers?
Is there a measured value of the damping factor for LA90 D in mono mode somewhere?
Isn't the use of LA90 D a "bottleneck" in a system with heavy speakers, which can lead to damage to equipment, such as tweeters?
I read that a low-power amplifier is worse than an amplifier with excessive power.

I use 2 LA90D's in Mono mode in combination with a DX9 and a pair of power hungry Marten Mingus Quintet loudspeakers. This combo is working great.
The temperature of the LA90D's stays rather cool during all day use. The temperature feels the same as my Audiophonics Nilai 500 power amplifier.

 

[Jess]

Utilice dos LA90D en modo mono, un DX9 y un par de altavoces Marten Mingus Quintet de alta potencia. Esta combinación funciona de maravilla.
La temperatura del LA90D se mantiene bastante fresca durante todo el día. La temperatura es similar a la de mi amplificador de potencia Audiophonics Nilai 500.

Uso dos LA90D en modo mono, un DX9 y un par de altavoces Marten Mingus Quintet de alta potencia. Esta combinación funciona de maravilla.
La temperatura del LA90D se mantiene bastante fresca durante todo el día. La temperatura es similar a la de mi amplificador de potencia Audiophonics Nilai 500.

I use 2 LA90D's in Mono mode in combination with a DX9 and a pair of power hungry Marten Mingus Quintet loudspeakers. This combo is working great.
The temperature of the LA90D's stays rather cool during all day use. The temperature feels the same as my Audiophonics Nilai 500 power amplifier.

Hi! Great to hear that. I’ve got the same setup with some Dynaudio Craft, and honestly, I’m thrilled with it. I’ve also tried it with the Merlin Audio VSM and they sound amazing, and even with the legendary B&W 801 Matrix3. The Topping drives them all effortlessly; on the contrary, it keeps surprising in a good way!