Topping LA90 Discrete Amplifier Review

[B.A.T.]

He heard distortion then made an oreo, then he throwed the remote second time to the floor.

Yeah, I posted it before I watched the video. My bad. I don't consider it a good review, it's mostly about distortion at peak levels.

 

[JktHifi]

Yeah, I posted it before I watched the video. My bad. I don't consider it a good review, it's mostly about distortion at peak levels.

I watch the video without audio because I listen to music. Only reading the en subs and watch him moving around and ordering food because he is hungry.

 

[Docmoggy]

What a great product! However, I too, like some others have reservations about the exterior power source. Having said that, the price to performance ratio is enough to put up with that inconvenience.

The issue that will prevent me from rushing out to buy a pair is the risk of the natural progression for Topping to drop out a dedicated mono power amp in the near future. The bridged performance is a pretty compelling argument. I mean, the architecture is there to deliver world class performance and it would be a natural synergistic evolution of the product line. Deleting the bulbous volume knob (not the most aesthetic design) and adding a power source in the existing package would require little brain power or, none at all. Even with the existing power supply would make absolute sense. Surely, such a desirable offering is perhaps well in the advanced stage of development?

 

[DrDen]

What a great product! However, I too, like some others have reservations about the exterior power source. Having said that, the price to performance ratio is enough to put up with that inconvenience.

The issue that will prevent me from rushing out to buy a pair is the risk of the natural progression for Topping to drop out a dedicated mono power amp in the near future. The bridged performance is a pretty compelling argument. I mean, the architecture is there to deliver world class performance and it would be a natural synergistic evolution of the product line. Deleting the bulbous volume knob (not the most aesthetic design) and adding a power source in the existing package would require little brain power or, none at all. Even with the existing power supply would make absolute sense. Surely, such a desirable offering is perhaps well in the advanced stage of development?

What a great product! However, I too, like some others have reservations about the exterior power source. Having said that, the price to performance ratio is enough to put up with that inconvenience.

The issue that will prevent me from rushing out to buy a pair is the risk of the natural progression for Topping to drop out a dedicated mono power amp in the near future. The bridged performance is a pretty compelling argument. I mean, the architecture is there to deliver world class performance and it would be a natural synergistic evolution of the product line. Deleting the bulbous volume knob (not the most aesthetic design) and adding a power source in the existing package would require little brain power or, none at all. Even with the existing power supply would make absolute sense. Surely, such a desirable offering is perhaps well in the advanced stage of development?

Most important — the next model should be a little wider (for better heat dissipation and more convenient access to all inputs).

 

[DrDen]

Most important — the next model should be a little wider (for better heat dissipation and more convenient access to all inputs).

 

[solderdude]

The establishment is doing their best to decipher the relationship between electronics circuit design & subjective audible preference.

Whoever 'the establishment' is/are they haven't been able to decipher the relationship between electronics circuit design & subjective audible preference in the last 40 years or so.
There is a very good reason for that.... human preference.
Preference and signal fidelity aren't the same thing. These things have never been the same and also will not be the same thing 40 years from now.

Performance is good enough but power output could be on the low side of things for a lot of speakers when wanting to play at impressive levels.
Sure... you can buy 2 of them use them BTL as monoblocks and need to buy an extra pre-amp.

 

[Toku]

Questions about LA90D/LA90.
The LA90D/LA90 uses a 64V single power supply.
By connecting two 35V/4700uF electrolytic capacitors in series, the power supply voltage is divided into two to simulate the same operation as when using a +32V/-32V power supply.
The negative terminal of the speaker output is connected to the voltage divider point of this series capacitor.
This circuit method is the same as the SE operation of the capacitor output, and the electrolytic capacitor is inserted in series in the speaker line, so I think it is a little disadvantageous for the bass output.
For reference, the SMSL A300 and Sabaj A20a 2022, which use the SE output of the MA5332MS chip, adopt a +- dual power supply system.

I think that low-cost amplifier products can accept this circuit method, but LA90D/LA90 class products should use positive and negative dual power supplies. I don't understand why Topping sticks to a single power supply because the power connector also uses a 3-prong one.
However, if you use it as monaural with BTL connection, this problem does not occur.
What do you guys think of this kind of power circuit system? "My knowledge and way of thinking may be a little outdated."

 

[voodooless]

This circuit method is the same as the SE operation of the capacitor output, and the electrolytic capacitor is inserted in series in the speaker line, so I think it is a little disadvantageous for the bass output.

But where is your proof? The measurements certainly don’t seem to agree with you:

 

[DrDen]

But where is your proof? The measurements certainly don’t seem to agree with you:

View attachment 279770

But LA90 has quite different graph.

 

[voodooless]

But LA90 has quite different graph.

That doesn't prove it's the power supply setup though. It could very well be a property of the chip.

 

[DrDen]

That doesn't prove it's the power supply setup though. It could very well be a property of the chip.

Newer design is obviously better in this aspect.

 

[voodooless]

Newer design is obviously better in this aspect.

It clearly is. However, we do see the 20 Hz go up a tad earlier:

Who knows why that is..? Can be a multitude of things.

 

[DrDen]

People just can’t believe the miracle of nearly perfect amp being so affordable)

 

[DrDen]

It clearly is. However, we do see the 20 Hz go up a tad earlier:
View attachment 279782
Who knows why that is..? Can be a multitude of things.

Such a small box can hardly produce sub bass.

 

[restorer-john]

Such a small box can hardly produce sub bass.

The size of the box is irrelevant to the LF extension properties. If it cannot reproduce its specified rated power across the audible bandwidth without shutting down it should be called out for that.

 

[Bleib]

Such a small box can hardly produce sub bass.

Canton GLE90 does it just fine together with LA90

I bet I could try something like Topping MX3s and still get plenty of deep bas. Class D yeah...but still smaller

 

[okok]

Toku sensei is very experienced, i think he got his point

 

[voodooless]

Toku sensei is very experienced, i think he got his point

Why?

 

[DrDen]

Canton GLE90 does it just fine together with LA90

I bet I could try something like Topping MX3s and still get plenty of deep bas. Class D yeah...but still smaller

Class AB is less efficient than D, so size does matter. 20 Hz is too low frequency to be reproduced by average speaker.

 

[Bleib]

Class AB is less efficient than D, so size does matter. 20 Hz is too low frequency to be reproduced by average speaker.

Yes, it's less efficient, speaker sensitivity also plays a role as well as impedance. Many, even here, all too often think they need huge amounts of power to drive their speakers but usually they use far less than they think.