Topping LA90 Review (Integrated Amplifier)

[RHO]

yes, fancy cables measure better... marginally. so marginally, as to being totally inaudible as we're talking literally fractions of a decibel. why would i try to "prove you wrong" when that's what i'm talking about? wth you on?


you're telling me my arguments are "ridiculous" when you had to go out of your way to construct an example by using headphones on a speaker amp with no headphone out just to try and prove a point? lol

the audible benefits are super marginal and very very very niche in an already niche category, but can be found even in the speaker world (given by people, even in this very thread, iirc)

i stopped reading here because this is taking "ridiculousness" to whole new highs

the whole point was that calling this amp "the best", and i'm repeating myself for probably the 10th time here, when it's inaudibly better than what people consider "the competition" in roughly 99,999% of the use cases, but is actually audibly worse (less gain, less power i.e. will clip sooner) in a lot of use cases... is counterproductive and is just changing one cult for another.

not to mention that 99,99% of the people into high end audio wouldn't be able to tell the difference in blind tests between this and your average flat fr "big brand" integrated amp with a sinad score of 80-90 with orders of magnitude more features, often at a fraction of the cost

What's the top speed of the car you own? What's the maximum speed you are allowed to drive it? Could you have bought one that was cheaper but a little slower but could still reach the maximum speed allowed?

 

[raest]

What's the top speed of the car you own? What's the maximum speed you are allowed to drive it? Could you have bought one that was cheaper but a little slower but could still reach the maximum speed allowed?

lol what? that's such a misguided and misinformed and ignorant attempt at an analogy it's not even worth the bytes onto which it is now permanently recorded on the internet

but i'll bite, just to see the lunacy that will follow: i own a Kia Proceed from 2008. maximum speed... where? do you know how vehicles and roads and the laws governing them work? because from your questions it doesn't appear that you do

 

[eboleyn]

You have a 110dB/W headphone with low impedance and you buy a speaker power amplifier to drive it? And you will be using the ****** pot to control the volume? I'm slightly confused.

Raal SR1a with modded cables and connected to a transformer to get that kind of sensitivity. Headphone amps work great for driving things with high impedance, but mostly not so great for low impedance, and most would heat up internally a huge amount in those kind of conditions, if not get damaged internally. You did note the "could go down to 4 ohms" comment, right?

I already use resistors ("passive preamps") to lower the input to amps for my sensitive driving applications, else it makes the noise floor from my DACs potentially go too high... but one is still subject to the distortion profile of the amp, tsk tsk.

Honestly do I intend on doing this regularly ... most probably not, though I'm curious how it will change the measurable sound characteristics to do that experiment. You could also have a super-sensitive speaker (in theory) that could have mildly insane low impedance too.

The main point was it's not beyond the stretch of imagination to have an application where ultra-low distortion could come into play as useful.

 

[F1308]

I'm an electrical engineer and this is bullshit

So a pillar is a pillar and that is it regardless of it being made of wood (many types available), iron, plastic...graphene...
Guess then the same goes for fuels. It burns. End of the story.
Finding a good material for the light bulb took some time, I was told.
And the music ? Just C D E F G A B and at times F# or Bb. Cannot be made to sound much different.
Jet engines...? THE COMMITTEE ON GAS TURBINES appointed by THE NATIONAL ACADEMY OF SCIENCES wrote.on June 10, 1940, that "In its present state, and even considering the improvements possible when adopting the higher temperatures proposed for the immediate future, the gas turbine engine could hardly be considered a feasible application to airplanes mainly because of the difficulty in complying with the stringent weight requirements imposed by aeronautics... .... ....", ending the note with "....a gas turbine seems beyond the real of possibility with existing materials"

Mr. Whittle nevertheless built the jet and when years later knew about that note he said : "Good thing I was too stupid to know this."

 

[IPunchCholla]

So a pillar is a pillar and that is it regardless of it being made of wood (many types available), iron, plastic...graphene...
Guess then the same goes for fuels. It burns. End of the story.
Finding a good material for the light bulb took some time, I was told.
And the music ? Just C D E F G A B and at times F# or Bb. Cannot be made to sound much different.
Jet engines...? THE COMMITTEE ON GAS TURBINES appointed by THE NATIONAL ACADEMY OF SCIENCES wrote.on June 10, 1940, that "In its present state, and even considering the improvements possible when adopting the higher temperatures proposed for the immediate future, the gas turbine engine could hardly be considered a feasible application to airplanes mainly because of the difficulty in complying with the stringent weight requirements imposed by aeronautics... .... ....", ending the note with "....a gas turbine seems beyond the real of possibility with existing materials"

Mr. Whittle nevertheless built the jet and when years later knew about that note he said : "Good thing I was too stupid to know this."

It would be nice if you cited the report, as I can’t find it and the British Air Ministry was testing planes with Whittle engines in 1939. My understanding is that development of the comet was slow due to safety concerns (pilots being more valuable than planes). Thus the quote you provide seems likely out of context and might be more reflective of resource allocation during an existential crisis, rather than pure possibility as it is used to imply here.

 

[antcollinet]

So a pillar is a pillar and that is it regardless of it being made of wood (many types available), iron, plastic...graphene...
Guess then the same goes for fuels. It burns. End of the story.
Finding a good material for the light bulb took some time, I was told.
And the music ? Just C D E F G A B and at times F# or Bb. Cannot be made to sound much different.
Jet engines...? THE COMMITTEE ON GAS TURBINES appointed by THE NATIONAL ACADEMY OF SCIENCES wrote.on June 10, 1940, that "In its present state, and even considering the improvements possible when adopting the higher temperatures proposed for the immediate future, the gas turbine engine could hardly be considered a feasible application to airplanes mainly because of the difficulty in complying with the stringent weight requirements imposed by aeronautics... .... ....", ending the note with "....a gas turbine seems beyond the real of possibility with existing materials"

Mr. Whittle nevertheless built the jet and when years later knew about that note he said : "Good thing I was too stupid to know this."

Jesus!

The statement was:

Skillful selection of capacitors is the whole secret of the art of audio.

No-one is saying capacitors make no difference. But they are a tiny tiny part of "the whole secret of audio" And once you have the main parameters tied down (value, ESR, tech appropriate to application, basic quality) then "selecting" them makes little to no difference.

 

[Ra1zel]

The main point was it's not beyond the stretch of imagination to have an application where ultra-low distortion could come into play as useful.

Actually it still is, noise? Fair. Distortion? I don't think so, unless of course someone has a proof.

 

[eboleyn]

Actually it still is, noise? Fair. Distortion? I don't think so, unless of course someone has a proof.

Ah you mean, can I hear the ultra-low distortion at full power? Haha, agreed no.

I am indeed talking about being able to get acceptable levels of distortion/noise as the signal goes far below the maximum output level.

So, if there were amplifiers whose distortion/noise levels stayed at some "no human can detect it" level as the output level went down, that would probably work for me too.

Clearly there is some form of that effect in many modern low-distortion amplifiers (including the Topping LA90), as you can see that as the output decreases from the maximum there is kind of a "sawtooth" of the noise/distortion floor until it finally reaches some minimum and then it just slopes up as the output level goes down.

 

[restorer-john]

Clearly there is some form of that effect in many modern low-distortion amplifiers (including the Topping LA90), as you can see that as the output decreases from the maximum there is kind of a "sawtooth" of the noise/distortion floor until it finally reaches some minimum and then it just slopes up as the output level goes down.

The 'sawtooth' as you describe it, is the Audio Precision switching gain/attentuation ranges to keep the signal for the onboard data aquisition A/Ds in their relative sweet spots for the greatest accuracy/lowest noise.

At extreme low input levels, there is a heap of gain applied to the signals, using very low noise amplifiers, in order to keep the signals applied to the A/Ds in their linear ranges. The rise before the vertical drop is the AP, not the DUT. As the applied input levels increase, the gain/attentuation is switched out, and at high levels, way above the A/D's input ranges, the signal is attentuated in ever increasing multiples to keep the A/Ds right in their full scale ranges. Less gain equals less intrinsic noise.

The AP's automatic range selection matrix would be quite impressive to look at all the combinations of nested gain stages and attenuation stages.

 

[usa_satriani]

Hello,

I have a active and efficient setup.
15" BMS sealed and corrected, 6.5" waveguided phl 1140, 1" faital hf108r sth100 horn.
Digital filters with RME DAC.
I have been using lab gruppen amps for years and I love them.

We are making a similar system for a friend, we got a lab gruppen for the lows.

I don't want to start a debate but has someone used this amp on a compression driver ? How does it react and play ?
The little brother in class d, same question and what would you pick between high end class D and high end class ab for the compression drivers (1.5-20khz).

Regards Greg

 

[Talisman]

ASR's point is measurement.

I would say that the point of ASR is conscious spending, in fact in ASR users are invited to demonstrate whether or not they hear a blind difference between two pieces (dacs, amplifiers, cables)
Can you hear a blinded difference between an LA90 and a PA5? And between a Marantz PM6007 and a LA90?
If you have a dac with sinad 115, do you think having one with sinad 125 will improve your system?
Psychoacoustics works for both shiny, heavy audiophile instruments and the wonders shown in the graphs, but the point of ASR is
CAN YOU EAR A DIFFERENCE THAT JUSTIFIES THE SPEND?
The answer can only be given by you

 

[manisandher]

... what would you pick between high end class D and high end class ab for the compression drivers (1.5-20khz).

Hi Greg, I don't really have a view on this, but wanted to let you know that I'm very happy with my Neurochrome amps (class AB, with clever error correction) driving my high horns (compression drivers, 1-20kHz). The horns are 107dB/W@1m, and with your ear right next to the mouth of the horn, all you hear is the faintest of hiss. And I can't find any fault in the sound (that could be due to the amps, at least).

But I've never compared the Neurochromes directly to any class D amps - never had the inclination, as I'm perfectly happy with the sound I currently have.

Good luck with your search.

Mani.

 

[Ra1zel]

Now people are complaining that 80wpc is not enough for them. Really.

Lots of trolling in this thread.

Since 36wpc into 8ohm is apparently all that anyone would ever need it makes me wonder why all those relatively small active studio monitors have hundreds of watts.

 

[kenshone]

So looking at the tests Amir did beyond the rated specs, ~120W into 4ohms bridged before clipping is pretty good. Topping advertises an 8ohm minimum load in bridged mode. 1) Are they being conservative since so many speakers rated at 8ohms nowadays actually dip to 4ohms or even lower or 2) is it dangerous for the LA90 to run it bridged into a "real" (as opposed to nominal) 4 ohm load?

Topping rates power here at 1% THD, but that point occurs during clipping. I think Amir's estimations are more useful -- the max power before clipping.

(This adds an appreciation for soft clipping circuitry, such as that found in NAD amps.)

 

[staticV3]

While WolfX-700 did not drive the LA90 up to 1% or 10% THD+N, his THD+N vs output power sweeps show that the Amp would most likely meet its spec:
https://www.l7audiolab.com/f/topping-la90/

 

[kenshone]

While WolfX-700 did not drive the LA90 up to 1% or 10% THD+N, his THD+N vs output power sweeps show that the Amp would most likely meet its spec:
https://www.l7audiolab.com/f/topping-la90/

To clarify, Amir's measurements more or less match Topping's advertised specs. 1% THD just happens to occur during clipping, and Amir rated max power BEFORE clipping.

 

[Billy Budapest]

To clarify, Amir's measurements more or less match Topping's advertised specs. 1% THD just happens to occur during clipping, and Amir rated max power BEFORE clipping.

It’s an informal convention for many manufacturers, reviewers, etc., to *define* clipping as 1% THD and then use the power measurement at 1% THD as the rated power at clipping, even if that specific 1% THD threshold is more or less arbitrary and does not really represent anything in particular. The real definition of clipping is when the power supply cannot supply enough juice to the output circuitry for an amp to fully reproduce the sine wave of the music signal and the top gets squared off (“clipped.”)

Now, realistically there probably isn’t much difference between the two.

 

[KSTR]

The 1% distortion point for power spec was historically established as this amount of clipping you'll start to recognize on an oscilloscope screen shot.
Personally, the whole fixation on "precision" clipping level measurement is moot as in practice an amp sounds louder and cleaner when it has clean soft clipping starting early (say, raising to 1% at 70% max voltage which relates to 50% power) than the same amp with hard clipping starting late and showing a bad recovery behavior ("rail sticking").
A distortion point at 1% or 0.1% or whatever (like Amir's "onset of visible change of the plot") only makes sense for hard clipping amps.
It would be helpful if signal waveforms would be posted at various distortion levels like 1% and 10%

 

[KSTR]

Since 36wpc into 8ohm is apparently all that anyone would ever need it makes me wonder why all those relatively small active studio monitors have hundreds of watts.

Universal studio monitors are used to, well, monitoring signals during any stage of music production and thus need way more headroom than speakers aimed at listening to the final product. You don't want to clip the internal amps on transients.
Not all products labelled studio monitors are in this universal class, however.

 

[MaxBuck]

The 1% distortion point for power spec was historically established as this amount of clipping you'll start to recognize on an oscilloscope screen shot.
Personally, the whole fixation on "precision" clipping level measurement is moot as in practice an amp sounds louder and cleaner when it has clean soft clipping starting early (say, raising to 1% at 70% max voltage which relates to 50% power) than the same amp with hard clipping starting late and showing a bad recovery behavior ("rail sticking").
A distortion point at 1% or 0.1% or whatever (like Amir's "onset of visible change of the plot") only makes sense for hard clipping amps.
It would be helpful if signal waveforms would be posted at various distortion levels like 1% and 10%

You've put your finger on one reason amplifiers may not all sound alike, at least when they're driven near their limits. And as for measurements and how they describe these behaviors, as you suggest it's not a matter of measurements being unable to describe them, it's the fact that the measurements that could describe them are rarely performed.