Topping LA90 Review (Integrated Amplifier)

[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.

 

[Aokman]

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

I have 3 “power amps” that have input switching and volume control. The volume is an attenuator, not an active preamp.

I don’t know of many amps with XLR inputs that use any sort of active preamp for them and the volume can be bypassed completely so it’s technically a power amp.

 

[dped90]

As Amir nor anyone else will likely have access to the complete circuit diagram, and between what you and TMTomh claim, there seems no way to be sure exactly what this beast really is. But I wish an actual LA90 user (s) would reply to my two questions, especially the second one.

 

[Bruce Morgen]

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

Nope -- a level control (or two) has been quite common in power amps for at least 60 years. Some -- like my old Kenwood KM-8002 from back in the day -- also had switchable line level RCA inputs and speaker selector switches!

 

[Aokman]

As Amir nor anyone else will likely have access to the complete circuit diagram, and between what you and TMTomh claim, there seems no way to be sure exactly what this beast really is. But I wish an actual LA90 user (s) would reply to my two questions, especially the second one.

All modern amplifiers worth any look at have speaker protection relays for power on / off thumps and DC detection. I have never heard anything of the sort from my LA90 and managed to even trigger the protection a couple times with overloads. Worked great.

Nope -- a level control (or two) has been quite common in power amps for at least 60 years. Some -- like my old Kenwood KM-8002 from back in the day -- also had switchable line level RCA inputs and speaker selector switches!View attachment 381146

Correct, most power amps dating back to the 70s have an attenuator on the left and right channels to limit max gain or balance the channels, speaker selectors etc. They can be hidden on the back sometimes also.

If the LA90 was a fully featured integrated, they wouldn’t sell a seperate preamp.

 

[Toku]

The meaning of "integrated amplifier (pre-main amplifier)"

An integrated amplifier is an amplifier that integrates a control amplifier (pre-amplifier) and a power amplifier (main amplifier). The control amplifier has built-in functions such as volume control, input selector, and tone control. The operation panel of an integrated amplifier is almost the same as that of a control amplifier, and since it has a built-in power amplifier, it has speaker terminals. Even if the control amplifier and power amplifier are integrated, there are some that have separate control amplifier circuits and power amplifier circuits inside, and some that have been integrated in terms of the circuit. In the former configuration, a control amplifier output terminal and a power amplifier input terminal may be provided, in which case they can be used separately as a control amplifier and a power amplifier housed in one housing. In other words, the control amplifier output terminal can be connected to the input of another power amplifier, or conversely, another control amplifier output can be connected to the input terminal of a power amplifier. In the latter configuration, it is not possible to do exactly the same thing, but it can be used as a power amplifier using a line input terminal such as an AUX input. However, recently, many products equipped with USB DACs and products that are not bound by traditional configurations due to digitalization have been produced, making it difficult to make a clear distinction. The term "integrated amplifier" is now almost obsolete and is probably only used by older audio fans.

 

[Head_Unit]

here the LA90 is called an integrated amp, but this reviewer says it's a power amp...And so does the brand. https://www.toppingaudio.com/product-item/la90-discrete

There is no input to directly access the power amp section, so it is not a "power amp," the end. OK yeah you could plug a preamp into an input and set the volume to some set level and use it like that, I do that with an Aiyima fed by a Bluetooth adaptor in one little setup. But that's not a "power amp" in the traditional sense. Does this thing have a remote? It doesn't seem to, which makes it useless in my book.

 

[Aokman]

It’s a power amp lol, like I said I have 3 power amps, all have multiple inputs and gain control. You can bypass the volume also. There is no degradation from switching XLR input signals.

An integrated is usually classed by having a phono section, active preamp with tone controls etc. Whatever works for everyone though lol none of its features affect sound quality at all.

 

[Ziofrenko]

All modern amplifiers worth any look at have speaker protection relays for power on / off thumps and DC detection. I have never heard anything of the sort from my LA90 and managed to even trigger the protection a couple times with overloads. Worked great.


Correct, most power amps dating back to the 70s have an attenuator on the left and right channels to limit max gain or balance the channels, speaker selectors etc. They can be hidden on the back sometimes also.

If the LA90 was a fully featured integrated, they wouldn’t sell a seperate preamp.

The separate preamp is for dual bridge amp and remote control... Not because the la90 is not an integrated.
If you first boost after you can attenuate: with high gain a preamp is not necessary.

 

[netcipher]

If the LA90 was a fully featured integrated, they wouldn’t sell a seperate preamp.

The preamp in the LA90 (D) is rather formal. If you need a high-quality relay volume control, then they suggest using an external preamp. Even in tests, Amir turned off the LA90 (D) preamp and performed measurements. Most likely, this was agreed with the manufacturer. If you conduct a survey here, then most of the owners of the LA90 (D) most likely do not use a preamp in it.
However, the presence of an input switch on the LA90 (D) provides additional flexibility in building audio system.

 

[mocenigo]

The preamp in the LA90 (D) is rather formal. If you need a high-quality relay volume control, then they suggest using an external preamp.Even in tests, Amir turned off the LA90 (D) preamp and performed measurements. Most likely, this was agreed with the manufacturer.If you conduct a survey here, then most of the owners of the LA90 (D) most likely do not use a preamp in it.

Sometimes Topping is weird. Like putting the preamp section in the LA90 or having three inputs in the B200. Why?

 

[netcipher]

Sometimes Topping is weird. Like putting the preamp section in the LA90 or having three inputs in the B200. Why?

The preamp on the LA90 looks logical, as its presence increases market coverage. On the B200, they wanted to keep the input switch for the same reason. Although most of the LA 90(D) and B200 users use only one input.

If there was one XLR input, then the reviewers would put it as a disadvantage. And so - another plus. The price of the issue is the cost of connectors and additional relays.