Topping LA90 evaluation and discussion (Integrated Amplifier)

[boXem]

They just built an amp with very, very, very good THD+N numbers. Maybe better than anyones. For a very small price too.

I don't have to tell you that THD and N are two of the most important key performance indicators for amps. They outperform anything ever measured by Amir with THD+N, and it's a long list of measurements.

N is exceptional, I already stated this.
I have a different opinion about the relevance of THD+N versus other parameters in the case of a power amplifier, but we are in a free world.

Yes. Why do you think this is in dispute?

I sincerely don't get what's happening. Topping honestly specifies a minimum load that is far from good. In my mind, it is a key parameter for an amplifier, much more than THD+N. I express this opinion. Why are personal attacks following this?

 

[TheBatsEar]

lol. how is offering SINAD numbers beyond audibility in a market that already provides that for similar prices but with multitudes more power while using less electricity "innovation"?

They do better THD and N for less money.

It's a competition thing. You wouldn't understand.

 

[solderdude]

Could we perhaps take one step back simply by putting a marker on our ranked bar charts labeled “limit of audibility” by some defined criterion value? Is that worth considering?

The problem here is whether or not the distortion measured at 1kHz only at (near) full power into resistive loads is representative for the amp performance when used for music enjoyment at well below clipping levels with complex loads.
Is the SINAD Noise or hum dominated or distortion dominated and if so what harmonic profile.
Then it also depends on how loud is played, speaker efficiency etc and music content dependent.

 

[pjug]

A wild stab, but I am guessing they are doing similar to Neurochrome with the LM3886. Then the 4 ohms comes from a combination of current limit and allowable power dissipation in the chip amp. So supply voltage dependent set of curves like below. With +/- 32V it looks like it would fall sharply below 4 ohms.

Of course Amir's testing will now show that I am completely wrong!

 

[theREALdotnet]

They just built an amp with very, very, very good THD+N numbers.

They specify a very low THD+N (-121dB) at 5W and 1kHz. Beyond these parameters things aren’t quite so pretty. Outside of 1kHz they specify -101dB. At 50W into 8 ohms THD+N is 1% (-40dB). So unless you’re listening to a lot of 1kHz at 5W, hardly class-leading I’d say.

 

[raest]

Yesterday Benchmark was the king, which was accepted. Today you don't agree it's Topping, because they don't have enough watts. How many watts does it take to accept their victory?

more than the ABH2, obviously, or at least a percentage approaching 80%. units lower in price than the Benchmark already reached stupid high SINAD levels at higher power, showing what actually can be done. as previously mentioned, QC aside, Topping's own PA5 has insane performance at the price... marginally lower SINAD than the LA90, while delivering significantly more power, in a smaller form factor, without problems driving complex loads... for a little more than a third of the price

this is, as mentioned, a genitalia waving product. you're free to wave it around all you want, from me you'll get the same contemptuous laughter that "my speakers go to 30kHz" and "my cables cost 5k €" audiofools get. same difference

 

[antcollinet]

Yes. Why do you think this is in dispute?

Because @muslhead is accusing @boXem | audio of "reading and assuming"

It isn't an assumption when it is toppings own words that are being read. It is a specification.

 

[antcollinet]

I think that Topping is thinking about the regular customer. The regular customer does not know that his 8 Ohm loudspeaker has a for instance 6 Ohm minimum impedance.
So I think that 8 Ohm means any 8 Ohm (or higher) specified loudspeaker and 4 Ohm means any 4 Ohm (or higher) specified loudspeaker. And yes, I know: loudspeaker manufacturers also make mistakes with their specifications.

That is possible. But unless topping can clarify we don't know. In any case it doen't change the fact that my 6ohm speakers are not suitable for this amp in mono mode, even according to the most favorable interpretation of that specification.

 

[Colonel7]

I skipped over the SINAD numbers this morning to power. An expensive underpowered desktop/kitchen amp, really? I was expecting 100 watts x2. Right now I'm not even tempted to replace a $35 2.1 TI 3116 DIY board that also drives a 4 ohm desktop sub at higher wattage than this thing. It is an important product for Topping however. Fantastic SINAD but if there are any reliability issues following the PA5 - uhh oh.

 

[fredoamigo]

Without wanting to be a bitter old fart or the "it was better before "
I would be curious to know the opinion of Bob Cordell today on this kind of thing?
http://jipihorn.free.fr/Documents/Divers Blog/Cordellinterview.pdf

 

[Keened]

I think it's a beautiful proof of concept that the majority of issues with A/B amps is poor engineering hygiene rather than an inherent limitation of class A/B.

...But we already knew that since class A has always had the option of this level of performance and the limitation was always power/efficiency with them. Hence A/B/H type designs.

Maybe they're trying to sway the tube people/horn/nearfield people who refuse class D on principle. They typically don't need a ton of wattage for their speakers and have higher impedance on average I think.

 

[Ra1zel]

Is the SINAD Noise or hum dominated or distortion dominated and if so what harmonic profile.

But does distortion profile matter when fundamentals are down 100dB?

 

[solderdude]

No, but that would mean the 'border' could be set unnecessary high.
Could well be 80 for most people.
And the question remains if the distortion is low at 1kHz whether or not this is also the case at low or high frequencies.

 

[GeekyBastard]

They do better THD and N for less money.

It's a competition thing. You wouldn't understand.

Notice the word Amir chose, “rumor”, I wonder whom in this thread spread this rumor hmmmmm...

 

[antcollinet]

View attachment 202709
Notice the word Amir chose, “rumor”, I wonder whom in this thread spread this rumor hmmmmm...

I think the "rumor" got created by the specifications published on the shenzhen audio website. Topping can hardly complain that people are saying you can only use 8ohm (or higher) speakers in mono mode when that is what they write in their own specs. When it is written in the specs it is not a rumor - it is a specification. Even if the device can beat the spec sheet - that doesn't stop it being a specification.

 

[JSmith]

I think there is quite a difference too between specs on Audiophonics' site and the manufacturer themselves (no detailed spec sheet there from what I see)... I mean they didn't even get the amp class correct on Audiophonics. It's certainly a fair point that was raised though based on that information and I doubt there was any nefarious intention in raising it. It's probably best to rely on the test results by Amir and Prof. Wolf at this point, not a spec page on a 3rd party sellers site. It's been made clear now that an actual 2 ohm load is no issue, so certainly no problems with speakers that dip into the 2 - 3 ohms region, which many do.

Some sage advice on the power supply...

... will remind me not to take the amp to the shower.


JSmith

 

[theREALdotnet]

Some sage advice on the power supply...

View attachment 202993

... will remind me not to take the amp to the shower.

Thanks for pointing that out. I was about to ask whether suction cups are provided to replace the standard rubber feet. I guess the answer is no.

 

[antcollinet]

I think there is quite a difference too between specs on Audiophonics' site and the manufacturer themselves (no detailed spec sheet there from what I see)... I mean they didn't even get the amp class correct on Audiophonics. It's certainly a fair point that was raised though based on that information and I doubt there was any nefarious intention in raising it. It's probably best to rely on the test results by Amir and Prof. Wolf at this point, not a spec page on a 3rd party sellers site. It's been made clear now that an actual 2 ohm load is no issue, so certainly no problems with speakers that dip into the 2 - 3 ohms region, which many do.

Some sage advice on the power supply...

View attachment 202993

... will remind me not to take the amp to the shower.


JSmith

Detailed spec sheet is on the the Topping site here:

LA90 Power Amplifier-TOPPING

 

[JSmith]

Detailed spec sheet is on the the Topping site here:

Sure, but it says the same as Audiophonics' minor specs showed;

So I can understand why the matter was raised by @boXem | audio as to whether this amp could drive a 2 ohm load. I think along the way there was some confusion between driving a 2 ohm load and dips into the 2 - 3 ohm region, which is all now moot anyway as per further testing results. I think we can lay this non-issue to rest.


JSmith

 

[antcollinet]

Sure, but it says the same as Audiophonics' minor specs showed;

View attachment 203023

So I can understand why the matter was raised by @boXem | audio as to whether this amp could drive a 2 ohm load. I think along the way there was some confusion between driving a 2 ohm load and dips into the 2 - 3 ohm region, which is all now moot anyway as per further testing results. I think we can lay this non-issue to rest.


JSmith

I linked them becasue you seemed to be suggesting the data on Audiophonics might not be accurate, and said there were no detailed specs from Topping. Sorry if I misinterpreted.