Topping LA90 Review (Integrated Amplifier)

[pepie34]

Hi All,

I recently bought a topping LA90 amplifier, which is really great in term of sound quality.
I’m really happy with the amplifier in term of sound except that it has the « boot» problem as described here before:
Generally the first power up in the day or after a long power off, the amplifier immediately power off after a power on.
I power it on again and then it works perfectly.

Here on the topping website, I see a firmware upgrade that state « Improve boot stability»
https://www.tpdz.net/newsinfo/642479.html
I followed the update procedure but the mass storage device never shows up.

I have tried on Mac, Windows and linux.
I have tried with multiple usb cables.
Usb-c <-> usb-c nothing happened
Usb- c <-> standard usb : the in1 light flashes twice then pause 1s again and again

On the linux log, I can see a mass storage device but with a lot of usb errors that keeps connecting and disconnecting (see at the log at end of this message).
Please note that the operation was done with nothing connected (no power cord, no speaker, no input) except the USB plug.

What should I do ? Is the amplifier broken ? Is there another way to perform the firmware update?
If someone has reached to the upgrade on which OS was it done ?

I'm still on the amazon returning policy period...

Best regards,

Pepie 34


Linux kernel USB log:
[ +0,367932] usb 2-3: new full-speed USB device number 18 using xhci_hcd [ +0,174263] usb 2-3: New USB device found, idVendor=0483, idProduct=5720, bcdDevice= 2.00 [ +0,000009] usb 2-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ +0,000004] usb 2-3: Product: Mass Storage in FS Mode [ +0,000003] usb 2-3: Manufacturer: STMicroelectronics [ +0,000002] usb 2-3: SerialNumber: 207030714D53 [ +0,017970] usb-storage 2-3:1.0: USB Mass Storage device detected [ +0,000560] scsi host10: usb-storage 2-3:1.0 [ +0,625761] usb 2-3: USB disconnect, device number 18 [ +0,321424] usb 2-3: new full-speed USB device number 19 using xhci_hcd [ +0,136246] usb 2-3: device descriptor read/64, error -71 [ +0,251760] usb 2-3: device descriptor read/64, error -71 [ +0,235999] usb 2-3: new full-speed USB device number 20 using xhci_hcd [ +0,136045] usb 2-3: device descriptor read/64, error -71 [ +0,244181] usb 2-3: device descriptor read/64, error -71 [ +0,109121] usb usb2-port3: attempt power cycle [ +0,410639] usb 2-3: new full-speed USB device number 21 using xhci_hcd

 

[Vini darko]

Hi All,

I recently bought a topping LA90 amplifier, which is really great in term of sound quality.
I’m really happy with the amplifier in term of sound except that it has the « boot» problem as described here before:
Generally the first power up in the day or after a long power off, the amplifier immediately power off after a power on.
I power it on again and then it works perfectly.

Here on the topping website, I see a firmware upgrade that state « Improve boot stability»
https://www.tpdz.net/newsinfo/642479.html
I followed the update procedure but the mass storage device never shows up.

I have tried on Mac, Windows and linux.
I have tried with multiple usb cables.
Usb-c <-> usb-c nothing happened
Usb- c <-> standard usb : the in1 light flashes twice then pause 1s again and again

On the linux log, I can see a mass storage device but with a lot of usb errors that keeps connecting and disconnecting (see at the log at end of this message).
Please note that the operation was done with nothing connected (no power cord, no speaker, no input) except the USB plug.

What should I do ? Is the amplifier broken ? Is there another way to perform the firmware update?
If someone has reached to the upgrade on which OS was it done ?

I'm still on the amazon returning policy period...

Best regards,

Pepie 34


Linux kernel USB log:
[ +0,367932] usb 2-3: new full-speed USB device number 18 using xhci_hcd [ +0,174263] usb 2-3: New USB device found, idVendor=0483, idProduct=5720, bcdDevice= 2.00 [ +0,000009] usb 2-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ +0,000004] usb 2-3: Product: Mass Storage in FS Mode [ +0,000003] usb 2-3: Manufacturer: STMicroelectronics [ +0,000002] usb 2-3: SerialNumber: 207030714D53 [ +0,017970] usb-storage 2-3:1.0: USB Mass Storage device detected [ +0,000560] scsi host10: usb-storage 2-3:1.0 [ +0,625761] usb 2-3: USB disconnect, device number 18 [ +0,321424] usb 2-3: new full-speed USB device number 19 using xhci_hcd [ +0,136246] usb 2-3: device descriptor read/64, error -71 [ +0,251760] usb 2-3: device descriptor read/64, error -71 [ +0,235999] usb 2-3: new full-speed USB device number 20 using xhci_hcd [ +0,136045] usb 2-3: device descriptor read/64, error -71 [ +0,244181] usb 2-3: device descriptor read/64, error -71 [ +0,109121] usb usb2-port3: attempt power cycle [ +0,410639] usb 2-3: new full-speed USB device number 21 using xhci_hcd

If remember rightly the amp comes with a usb wire for firmware updates. Try using that. Sure I remember another poster here having the same issue with wires and the topping supplied one solved it.
Edit: I don't remember rightly at all sorry.

 

[pepie34]

If remember rightly the amp comes with a usb wire for firmware updates. Try using that. Sure I remember another poster here having the same issue with wires and the topping supplied one solved it.

nope, no usb wire in the box, I have double check with the content list on the user manual: no usb wire mention either.
I have checked multiple cables also

If someone reached to do the upgrade, please can he/she tell me which kind of cable to use ?
male usb c <-> male usb c do nothing at all
male usb c <-> male old usb : a lot of usb error

 

[simplywyn]

I would be incredibly curious to know if you would be able to recognize them blindly.
I don't understand how you can so clearly recognize amplifiers with flat response and absolute load independence.

hmm, I plugged them in side by side...

I dunno, it's really obvious the difference.

1ET400 there's tremendous power, but not as much detail, bass is sharp but not as full as NC502MP, highs are not as rolled off but not as sharp as LA90
LA90 there's ton of detail, and very clean signal, highs are very sharp
NC502MP - bloated bass region, the highs and rolled off, detail is far worse

 

[Talisman]

hmm, I plugged them in side by side...

I dunno, it's really obvious the difference.

1ET400 there's tremendous power, but not as much detail, bass is sharp but not as full as NC502MP, highs are not as rolled off but not as sharp as LA90
LA90 there's ton of detail, and very clean signal, highs are very sharp
NC502MP - bloated bass region, the highs and rolled off, detail is far worse

Forgive me, I ask you without any controversy or mockery, it's just that I don't understand.
two amplifiers that have been measured with an absolutely flat response to the input signal, and that show no variance to the load, how do you explain that they can have such a different response in the bass that it is clearly perceived? Swollen bass presupposes an unexplained difference in equalization.

 

[Sokel]

hmm, I plugged them in side by side...

I dunno, it's really obvious the difference.

1ET400 there's tremendous power, but not as much detail, bass is sharp but not as full as NC502MP, highs are not as rolled off but not as sharp as LA90
LA90 there's ton of detail, and very clean signal, highs are very sharp
NC502MP - bloated bass region, the highs and rolled off, detail is far worse

Measurements of both Purifi and LA90 showed that if there are any differences are far down and not audible.
That's their worth (apart from the Purifi's power)
Do a proper controlled blind test.

 

[mike70]

Class D presents more uniform response to impedance variations and more power... so, with difficult speakers and higher sound pressure (big room, as an example), even with "similar quality" linear amplifiers, class D can have an advantage.

With a standard room / acoustics, decent speakers sensitivity and normal SPL ... amplifiers are much the same than different... unless they have a really bad design.

The bigger difference is in our mind.

 

[pepie34]

nope, no usb wire in the box, I have double check with the content list on the user manual: no usb wire mention either.
I have checked multiple cables also

If someone reached to do the upgrade, please can he/she tell me which kind of cable to use ?
male usb c <-> male usb c do nothing at all
male usb c <-> male old usb : a lot of usb error

Ok I 've reached to do the update after a reply from the topping after sale service. If it helps anybody:

It can be done on MS Windows only (not MacOS as stated in the firmware update doc) and the cable need to be (usb a <-> usb c) not (usb c <-> usb c).

Actually I don't understand how a usb device declared as a usb mass storage can work only on windows but not on Mac or even Linux...
(I mean the usb and scsi levels should work everywhere for a mass storage)

Nevertheless, the update protocol is quite neat:

1. unplug everything including the power cable (very important)
2. plug the device to a computer
3. it appears as a mass storage device
4. a text file in the new drive gives you the current version of the firmware
5. you drop the firmware update file on the drive
6. the drive ejects itself
7. the drive reconnect and a new text file tells you that the update went ok

No need for a special driver or update software on the computer, it's very clever.
If it could correctly work on Mac or Linux (which is probably not far away), it will be perfect.

 

[staticV3]

Actually I don't understand how a usb device declared as a usb mass storage can work only on windows but not on Mac or even Linux...

Maybe the LA90 in this firmware update mode uses a file system that macOS can't write to.
Care to check using Windows' Disk Management tool?

 

[pepie34]

Maybe the LA90 in this firmware update mode uses a file system that macOS can't write to.
Care to check using Windows' Disk Management tool?

No the problem it is way before filesystem compatibility.
On MacOS is not even listed on the usb device tree.
On Linux, usb mass storage and scsi are correctly initialised but when the os try to read it at the block level the device generate read errors (see the kernel logs on previous message).
It can't even read a partition table from it for example.

I think (I'm may be wrong) but it is like the microcontroller inside the amp is trying to emulate a usb mass storage (UMS) device, but it is expecting the exact sequences of request of the windows OS. It is not good in a long term perspective as a change in the way windows handles UMS may break the compatibility also for windows users.
They should have make it work on different OS, or stick to the UMS standard to ensure long term maintainability.

 

[simplywyn]

Measurements of both Purifi and LA90 showed that if there are any differences are far down and not audible.
That's their worth (apart from the Purifi's power)
Do a proper controlled blind test.

Okay just did. The differences are huge. I got my wife to plug A, B, and write down what I thought

Does anyone here actually have a LA90 an d a Prufi 1ET400 EVAL1? I'm curious as to what others think. I don't care about comments from people who just read charts, those who have both, please see if you can corroborate my listening effects:

LA90 - SMOOOTH, listened to Top Gun intro, and when it gets noisy it doesn't lose detail and keeps on going, when the guitar comes in, oh my smooth to my ears
1ET400 - deep pounding bass, much stronger than LA90 in the lower hz, my R11 really thundered, but once things crescendos, there a lot of noise, and your ears feel like they're being blasted with noise. The guitar solo doesn't sound as smooth or clear, there feels like way more noise than the LA90

I could tell immediately which one was LA90 and which one was 1ET400, 100% without fail even when adjusting to the volume. 1ET400 has a clear bass advantage whereas the LA90 has a clear advantage in terms of sharpness and responsiveness (I don't know the audiophile words here, fill them in). Drums on 1ET400 have boom, but not the sharp slack of the LA90. Overall I feel like LA90 is underpowered, but is good enough for normal music. 1ET400 can really shake my house, it's gut wrenching bass sometimes I feel like my floors are shaking. LA90 I feel like were clipping when I went too high

 

[mike70]

What's your preamp? You're not overflowing the Purifi input sensitivity?

 

[Doodski]

Okay just did. The differences are huge. I got my wife to plug A, B, and write down what I thought

Does anyone here actually have a LA90 an d a Prufi 1ET400 EVAL1? I'm curious as to what others think. I don't care about comments from people who just read charts, those who have both, please see if you can corroborate my listening effects:

LA90 - SMOOOTH, listened to Top Gun intro, and when it gets noisy it doesn't lose detail and keeps on going, when the guitar comes in, oh my smooth to my ears
1ET400 - deep pounding bass, much stronger than LA90 in the lower hz, my R11 really thundered, but once things crescendos, there a lot of noise, and your ears feel like they're being blasted with noise. The guitar solo doesn't sound as smooth or clear, there feels like way more noise than the LA90

I could tell immediately which one was LA90 and which one was 1ET400, 100% without fail even when adjusting to the volume. 1ET400 has a clear bass advantage whereas the LA90 has a clear advantage in terms of sharpness and responsiveness (I don't know the audiophile words here, fill them in). Drums on 1ET400 have boom, but not the sharp slack of the LA90. Overall I feel like LA90 is underpowered, but is good enough for normal music. 1ET400 can really shake my house, it's gut wrenching bass sometimes I feel like my floors are shaking. LA90 I feel like were clipping when I went too high

It seems you have a classic situation of one amp with lots more power out dB'ing the other. Not surprising is the description you came with.

1ET400A - PURIFI

Single-channel, analog-input Class D amplifier module Negligible THD and IMD Extraordinary low noise Load-invariant response Exceptionally clean clipping Low losses & high efficiency Easy to integrate Designed in Denmark KEY SPECIFICATIONS

purifi-audio.com

EVAL1 - PURIFI

EVAL1 is a kit combining two 1ET400A amplifier modules and a stereo front-end board. Highly suited for DIY projects and convenient for quickly evaluating performance of 1ET400A. The kit includes the CAB1 cable set for easy connection to a power supply. (For more info see CAB1 product description)

purifi-audio.com

LA90 Power Amplifier-TOPPING

 

[simplywyn]

What's your preamp? You're not overflowing the Purifi input sensitivity?

I am using a freya s+ in passive mode

Please tell me more about this overflowing

 

[mocenigo]

It seems you have a classic situation of one amp with lots more power out dB'ing the other. Not surprising is the description you came with.

Indeed. The Purifi is one of the “smoothest” amplifiers I have ever heard. I am talking of a “DHT 2A3 amplifier with over engineered power supply” level of smoothness. This is how my build has been described (Neurochrome Universal Buffer in front or normal buffer boards with the active circuitry bypassed). So one can easily be tempted to pump up the volume of the Purifi with corresponding loss of detail in the mids and treble due to room reflections, but the bass is wow. And that’s what forms the overall impression of the listener. The other amp then wins on the details because the most lasting impression it gives is at a lower volume.

I would be VERY surprised if they were distinguishable when not playing with the volume.

 

[simplywyn]

Indeed. The Purifi is one of the “smoothest” amplifiers I have ever heard. I am talking of a “DHT 2A3 amplifier with over engineered power supply” level of smoothness. This is how my build has been described (Neurochrome Universal Buffer in front or normal buffer boards with the active circuitry bypassed). So one can easily be tempted to pump up the volume of the Purifi with corresponding loss of detail in the mids and treble due to room reflections, but the bass is wow. And that’s what forms the overall impression of the listener. The other amp then wins on the details because the most lasting impression it gives is at a lower volume.

I would be VERY surprised if they were distinguishable when not playing with the volume.

Interesting analysis - this could be the reason, thanks for your thoughts. In terms of volume, both can be turned way up, but I'm guessing LA90 isn't producing anywhere near what the 1ET400 is producing.

Would you guys recommend I go for the 7040's? Tempted to get dual mono of those and try them out.

Room reflections, I've treated my room somewhat but not as much as my listening room where my LA90 currently sits. I'll have to do another comparison there.

 

[mike70]

I am using a freya s+ in passive mode

Please tell me more about this overflowing

Preamps and power amps must match in impedance ratio and gain.
Generally, that kind of electrical mismatch generates the big differences between them.

Input impedance in the power amp must be greater than 10 times the preamp output impedance and preamp gain must be enough to get the max power in the amp ... but not to saturate the input sensitivity.

That kind of things are usually not checked in many amateur comparations.

 

[simplywyn]

Preamps and power amps must match in impedance ratio and gain.
Generally, that kind of electrical mismatch generates the big differences between them.

Input impedance in the power amp must be greater than 10 times the preamp output impedance and preamp gain must be enough to get the max power in the amp ... but not to saturate the input sensitivity.

That kind of things are usually not checked in many amateur comparations.

In terms of Freya S+ and the 1ET400, am I saturating the input sensitivity in this case?

 

[mike70]

In terms of Freya S+ and the 1ET400, am I saturating the input sensitivity in this case?

Well, we need to have the specs and do the math ... are you using it balanced or unbalanced?

Freya output impedance is 75 ohms unbalanced and 600 ohms balanced. In passive mode there's no gain and with gain we have 12 dB. We need also the output voltage in the source (streamer, CD player, etc.).

In the other side we need to know the specifications in the amplifier input buffer, there're many. As an example I checked one version in Apollon Audio:
Input sensitivity 2.52 V (that means with 2.52V you're getting the max output ... )
47k input impedance

And so on ... But that kind of stuff must be checked... That's why many times the pre and power amp of the same brand works better together.

 

[Sokel]

Okay just did. The differences are huge. I got my wife to plug A, B, and write down what I thought

Does anyone here actually have a LA90 an d a Prufi 1ET400 EVAL1? I'm curious as to what others think. I don't care about comments from people who just read charts, those who have both, please see if you can corroborate my listening effects:

LA90 - SMOOOTH, listened to Top Gun intro, and when it gets noisy it doesn't lose detail and keeps on going, when the guitar comes in, oh my smooth to my ears
1ET400 - deep pounding bass, much stronger than LA90 in the lower hz, my R11 really thundered, but once things crescendos, there a lot of noise, and your ears feel like they're being blasted with noise. The guitar solo doesn't sound as smooth or clear, there feels like way more noise than the LA90

I could tell immediately which one was LA90 and which one was 1ET400, 100% without fail even when adjusting to the volume. 1ET400 has a clear bass advantage whereas the LA90 has a clear advantage in terms of sharpness and responsiveness (I don't know the audiophile words here, fill them in). Drums on 1ET400 have boom, but not the sharp slack of the LA90. Overall I feel like LA90 is underpowered, but is good enough for normal music. 1ET400 can really shake my house, it's gut wrenching bass sometimes I feel like my floors are shaking. LA90 I feel like were clipping when I went too high

One word: power.
There's no substitute to it all other things equal.