Topping LA90 Review (Integrated Amplifier)

[nagster]

As I recall, we compared 5 to 6 points during the preliminary measurements. The difference between A and B was about plus or minus 0.1dB.

 

[SashaR]

The difference between A and B was about plus or minus 0.1dB.

I thank you again - not only for your clarification, but also for your patience and forbearance with my inability to formulate my question clearly and understandably! Thank you very much!

I hope I understood your graph correctly: the best SINAD is provided by using the Behringer Monitor1, whose SINAD is better than the D90SE SINAD by 7 dB at a signal level of -27 dB.

I am interested in a slightly different question: how much does SINAD of the D90SE deteriorate when I'm using D90SE in PRE-amplifier mode (volume adjustment with the built-in digital volume control) compared to SINAD D90SE used in DAC mode?
From your graph I couldn’t figure out exactly this: it seems to me that you were figuring out the SINAD of the superposition of the D90SE DAC with an external volume control - but I’m interested in how much the SINAD of the D90SE deteriorates when it is used in PRE-amplifier mode?

For example, TOPPING insists that volume control must NOT performed using the D90CE, but using the LA90 volume control - apparently due to the significant deterioration of the D90CE's SINAD when used in PRE-amp mode. It is this difference that I would like to know at several points in the range from -50dB to -10dB , when they are shown on the D90SE display.

Once again, excuse me for my inability to ask my question clearly and simply!

 

[staticV3]

I am interested in a slightly different question: how much does SINAD of the D90SE deteriorate when I'm using D90SE in PRE-amplifier mode (volume adjustment with the built-in digital volume control) compared to SINAD D90SE used in DAC mode?

When you use the D90SE's Preamp function, then you lose ~1dB SINAD for each dB in volume reduction.

D90SE in DAC mode and D90SE in Pre mode with volume set to Max will result in identical SINAD.

 

[SashaR]

then you lose ~1dB SINAD for each dB in volume reduction.

That is, the intermodulation distortion of the D90SE at -20 dB on its screen means in practice that I have degraded the sound purity by ~20 dB?

 

[antcollinet]

That is, the intermodulation distortion of the D90SE at -20 dB on its screen means that I have degraded the sound purity by 20 dB?

No, most (or all) of the loss in Sinad, comes from the reduction of SNR. You are reducing the signal, but the noise floor doesn't reduce. So SNR reduces. The level of disortion products will also go down with the volume.

However this doesn't really matter If the noise was inauduble before you turned down the volume. Then it is still inaudible after you've turned down the volume.

 

[staticV3]

That is, the intermodulation distortion of the D90SE at -20 dB on its screen means that I have degraded the sound purity by 20 dB?

IMD does not get worse, regardless of what volume you set your D90SE to. Neither does THD.

Only the signal level decreases.

 

[SashaR]

most (or all) of the loss in Sinad, comes from the reduction of SNR

IMD does not get worse, regardless of what volume you set your D90SE to. Neither does THD.

That is, my ears are not deceiving me and the sound quality has NOT deteriorated from changing the LA90 regulator to the D90SE regulator? And I don't need to add a regulator and cables between D90SE and LA90?


Hooray! Thanks to both of you! Maybe you know the answer to one more question: how to make LA90SE not notice (not decode) MQA tracks? (I listen to classics from Tidal using the UAPP Pro application).

 

[staticV3]

Maybe you know the answer to one more question: how to make LA90SE not notice (not decode) MQA tracks? (I listen to classics from Tidal using the UAPP Pro application).

Try disabling MQA Passthrough in the UAPP settings.

 

[SashaR]

Try disabling MQA Passthrough in the UAPP settings.

I'm not familiar with this option for this Android application. In addition, even a Windows application (in which such a switch exists) will not be able to solve this problem: LA90SE autonomously and independently responds to commands in the file and switches itself to execution (execution the filters?) the MQA. (Note, Even decoding the MQA with an application does not prevent D90SE from seeing that it is receiving an MQA file).

Yesterday for the first time I came across an album that was simply spoiled by MQA processing (Tidal has both the original and its MQA).

I again expressed myself inaccurately. I don't want ANYONE to execute MQA commands - neither the application nor D90SE.

 

[staticV3]

I again expressed myself inaccurately. I don't want ANYONE to execute MQA commands - neither the application nor D90SE.

In that case, I think that your best options would be to either wait for Tidal to complete its migration to FLAC, or to switch to Qobuz.

 

[SashaR]

either wait for Tidal to complete its migration to FLAC, or to switch to Qobuz.

I don't know who continues to create MQA versions of classical music albums. Typically, without comparison to the original album, I don't hear anything terrible about MQA albums - and there's almost always, to my ears, no very noticeable difference between the editions.
I still haven't found a way to persuade Qobuz to sell me his service: he doesn't sell it to my country...

 

[antcollinet]

I don't know who continues to create MQA versions of classical music albums. Typically, without comparison to the original album, I don't hear anything terrible about MQA albums - and there's almost always, to my ears, no very noticeable difference between the editions.
I still haven't found a way to persuade Qobuz to sell me his service: he doesn't sell it to my country...

While MQA was a pointless money grab, from my understanding you should not hear any quality degradation from listening to MQA encoded music, if it is from the same master.

My suggestion is to just enjoy the music and stop worrying about how it is encoded, especially if there is no way to disable it.

 

[nagster]

I am interested in a slightly different question: how much does SINAD of the D90SE deteriorate when I'm using D90SE in PRE-amplifier mode (volume adjustment with the built-in digital volume control) compared to SINAD D90SE used in DAC mode?
From your graph I couldn’t figure out exactly this: it seems to me that you were figuring out the SINAD of the superposition of the D90SE DAC with an external volume control - but I’m interested in how much the SINAD of the D90SE deteriorates when it is used in PRE-amplifier mode?

It looks to me like the difference you're concerned about is shown in the graph.
The red line on the graph = B (DAC mode) ≈ A (PRE mode). Please also read post-1968471/#2363 again.

I recommend that you compare and listen to the volume adjustment methods yourself and enjoy using the one you like best. If you can't hear any difference, just choose the method that is most convenient for you.

 

[SashaR]

you should not hear any quality degradation from listening to MQA encoded music, if it is from the same master.

The first link is an album (encoded?) in a 192*24 container: it is unlikely that this is an original recording. The second link is the MQA version of this album. In your opinion, which of these versions spoiled the original recording more?

Gidon Kremer - New Seasons - Glass, Pärt, Kancheli, Umebayashi

Listen to New Seasons - Glass, Pärt, Kancheli, Umebayashi on your streaming service

tidal.com

Gidon Kremer - New Seasons - Glass, Pärt, Kancheli, Umebayashi

Listen to New Seasons - Glass, Pärt, Kancheli, Umebayashi on your streaming service

tidal.com

 

[antcollinet]

HI
Could someone help me?
How much gain I need in the preamplifier to connect to the LA90?

It depends on the voltage out of your source.

Voltage senstivity on high gain is 2.2V - so for full power you need to be able to send that to your amp.

If your source can output 4V, then you don't need any gain.
If your source outputs less than 2.2V you need some gain to get to 2.2V

If you want to use the amp on low gain - then sensitivity is 7.3V and you need enough gain to reach this from your preamp.

You can use this gain calculator
Use the voltage gain section - eg if your source can output 2V and you want to use low gain on the amp:

 

[Ziofrenko]

HI
Could someone help me?
How much gain I need in the preamplifier to connect to the LA90?

to know how much Volts are out from your Pre there are a lot on line converters from dBu or dBV to volts and viceversa.

 

[dped90]

Probably, a minor point, considering noise and distortion (??), but here the LA90 is called an integrated amp, but this reviewer says it's a power amp.

Topping LA90 Review - The Absolute Sound

What kind of amplifier performance do you get for under a grand? Steven Stone reports on this ultra-affordable Topping LA90 power amplifier.

www.theabsolutesound.com

And so does the brand. https://www.toppingaudio.com/product-item/la90-discrete

But if this amp's no longer available what's the best substitute, for the same or twice or so the price?

 

[Ziofrenko]

Probably, a minor point, considering noise and distortion (??), but here the LA90 is called an integrated amp, but this reviewer says it's a power amp.

Topping LA90 Review - The Absolute Sound

What kind of amplifier performance do you get for under a grand? Steven Stone reports on this ultra-affordable Topping LA90 power amplifier.

www.theabsolutesound.com

And so does the brand. https://www.toppingaudio.com/product-item/la90-discrete

But if this amp's no longer available what's the best substitute, for the same or twice or so the price?

A power amp, generically, has one only input... This one has 3, So it can't be a power amp.

 

[tmtomh]

A power amp, generically, has one only input... This one has 3, So it can't be a power amp.

Agreed - and it has a volume control. Adjustable volume + input switching = preamp in my book.

A number of web sites call it a power amp, which is interesting. And that Absolute Sound review talks about using two of them with a PRE90, so I can understand the confusion, since the LA90 can be "converted" to power amp mode that way.

 

[dped90]

But with the input stage bypassed when in power amp mode, are the adjustable input level controls still enabled, as they, of course are, on the Benchmark AHB2?

Also, might anyone know that if when used with the DM7 DAC, if you forget to power the DAC on first and hit the mute on button on its remote-and instead wrongly turn the LA90 on first-will you get loud thumps or pops? I'm worried about this for hearing safety because I have > 93db SPL/w/m speakers in a < 3000 cu ft room.