Topping A70 Pro HP & Preamp Review

[marcom22]

As headphone amp it's a beast BUT also with firmware 2.02 the audio dropping issue persists .......... unfortunately. Try to write first to the reseller ShenzenAudio, later to Topping.
EDIT:
BAL in -> HPA 6.35 out same song same interval ..... if I pump the volume around at -9.0db the drop occurs ..... if I low the volume from -12/-13db the drop doesn't occurs. The problem seems related to frequency and power drain.

 

[Antagron]

As headphone amp it's a beast BUT also with firmware 2.02 the audio dropping issue persists .......... unfortunately. Try to write first to the reseller ShenzenAudio, later to Topping.
EDIT:
BAL in -> HPA 6.35 out same song same interval ..... if I pump the volume around at -9.0db the drop occurs ..... if I low the volume from -12/-13db the drop doesn't occurs. The problem seems related to frequency and power drain.

Is the screen on VU mode? Does the dropout happen in all 3 modes with the same frequency?

 

[marcom22]

Is the screen on VU mode? Does the dropout happen in all 3 modes with the same frequency?

All 3 modes

 

[marcom22]

Hi, I just registered to this forum so I could post a potential solution. I had the same issue as you, and using the VU meter display did indeed make it come up more frequently. I contacted the reseller with a precise description of what the issue is and how to reproduce it, they talked with Topping and got back to me with a brand new firmware, version V2.02! It seems to be compiled today, fresh off the press. I flashed it and the issue seems to be resolved, but it's only been 20 minutes since flashing it. For what it's worth, I could play the same track on repeat which would trigger the cutout every time on the previous firmware. If any of you guys have the same issue, give this FW a try and please report back if it helped.
Also, I think the readme on how to flash is incorrect. Here's what I did:

1. Switch off the power supply
2. Plug in a USB-C cable
3. Hold down the volume button then power on the power supply, don't release the volume knob until the "DFU" screen appears
4. A 5MB removable drive will show up on your computer, open it
5. Copy the "A70 Pro FW202.Topping" file in there - the drive will disappear after a couple of seconds
6. Flashing starts, you'll see a progress bar on the screen
7. Flashing OK - you can power cycle the AMP and that's it!

I hope Topping releases this FW officially as well, but I thought I'd share this since I guess it's not only me who was driven insane by this issue.
Happy Holidays!

For your info I had to disconnect all the cables (audio input and output included) to make the topping visible under Windows, otherwise the USB device would not be recognized.

 

[raif71]

I wonder will the disconnect happen if I use DAPs instead of windows as music source.

 

[SirD_P]

One quibble with the A70 Pro firmware instructions, a standard USB-C to USB-C cable does NOT work for firmware updates. Due to what I suspect is non-USB IF compliant USB port, it needs USB-C to USB-A cable for the virtual firmware drive to appear on the computer. The A90D has the same gimped port. Too bad to see Topping ignore USB standards and not fix the USB-C port.

I am not a noob when it comes to flashing firmware updates but i havent been able to flash to latest 2.02 yet.
My unit has 2.01 and i received it today.
I connect the A70 Pro to my Mac Mini M2 Pro running latest sonoma 14.2.1 using a usb type c to usb type a cable.
when i connect the devices with the A70 Pro being unplugged it gets mounted on macOS as a TOPPING volume.
The topping at this point is fully switched off with power cable unplugged.

The instructions of the firmware download itself says just copy the .Topping file to the root of the removable drive.

Important note:

1, Unplug the power cord from the device.

Firmware Upgrade Process:
1, Connect the device's FW to a PC/Mac via a usb type-C cable. A removable drive will show up in the explorer
2, Open the drive.
3, Copy the .Topping file to the root directory of the drive. The drive will then eject itself and reconnect.
4, Reopen the drive. A new file will be showing current firmware version as "OKVERXX" of which
the "XX" showing the new firmware version indicates that the firmware is successfully upgraded.

I've downloaded the file multiple times on different systems and the checksum of the zip and the .Topping file is always the same so I think I ruled out file corruption.
When i copy the file the display of the topping immediately shows in red text: firmware damage and then unknown file.

The instructions of the readme.txt file in the removable drive says:

Update steps:
1. In the shutdown state, press the multifunctional button and do not let go. After powering on, let go until "TOPPING FW"U disk appears.
2. Drag the firmware with the topping suffix to the USB flash drive to upgrade.
3. Wait for the upgrade, which takes about one minute, during the upgrade, the USB flash drive device will restart several times
4. "Update successful(Version.xxxx).txt" will be displayed after firmware upgrade.

when they say 'after powering on' .. that is the confusing part to me.
the moment i plug in the usb cable to the topping with the unit still off and power cabler unplugged, it will immediately go into DFU mode and showing it has version V2.01
should i unplug usb cable again, then plug power cable back in, leave unit switched off and then connect usb ?
i simply cant get the topping to show that 'topping fw'U message!

Any help would be appreciated

 

[Antagron]

I am not a noob when it comes to flashing firmware updates but i havent been able to flash to latest 2.02 yet.
My unit has 2.01 and i received it today.
I connect the A70 Pro to my Mac Mini M2 Pro running latest sonoma 14.2.1 using a usb type c to usb type a cable.
when i connect the devices with the A70 Pro being unplugged it gets mounted on macOS as a TOPPING volume.
The topping at this point is fully switched off with power cable unplugged.

The instructions of the firmware download itself says just copy the .Topping file to the root of the removable drive.

Important note:

1, Unplug the power cord from the device.

Firmware Upgrade Process:
1, Connect the device's FW to a PC/Mac via a usb type-C cable. A removable drive will show up in the explorer
2, Open the drive.
3, Copy the .Topping file to the root directory of the drive. The drive will then eject itself and reconnect.
4, Reopen the drive. A new file will be showing current firmware version as "OKVERXX" of which
the "XX" showing the new firmware version indicates that the firmware is successfully upgraded.

I've downloaded the file multiple times on different systems and the checksum of the zip and the .Topping file is always the same so I think I ruled out file corruption.
When i copy the file the display of the topping immediately shows in red text: firmware damage and then unknown file.

The instructions of the readme.txt file in the removable drive says:

Update steps:
1. In the shutdown state, press the multifunctional button and do not let go. After powering on, let go until "TOPPING FW"U disk appears.
2. Drag the firmware with the topping suffix to the USB flash drive to upgrade.
3. Wait for the upgrade, which takes about one minute, during the upgrade, the USB flash drive device will restart several times
4. "Update successful(Version.xxxx).txt" will be displayed after firmware upgrade.

when they say 'after powering on' .. that is the confusing part to me.
the moment i plug in the usb cable to the topping with the unit still off and power cabler unplugged, it will immediately go into DFU mode and showing it has version V2.01
should i unplug usb cable again, then plug power cable back in, leave unit switched off and then connect usb ?
i simply cant get the topping to show that 'topping fw'U message!

Any help would be appreciated

When it's in the FW Update mode can you just copy the firmware file to the TOPPING drive? I think that's all you need to do.

 

[SirD_P]

I had a weird problem with updating my A70 Pro from 1.04 to 1.07. I've used my Mac before for other Topping updates with zero issues. This week on Sonoma every time I dropped the .topping firmware file on the fake topping USB drive, the LCD would say invalid firmware. This exact same process worked before. So I do the same operation on my Windows 11 PC, and viola, worked the first time. On my Mac I even re-downloaded the zip 3x and used two different unarchivers. AND I did a MD5 checksum on both my Mac and PC for the .topping file, and they matched. Weird?

Exactly the same issue. latest sonoma 14.2.1 , downloaded the file multiple times using different methods (curl, firefox, chrome) .. sha256sum was always the same.
dragging the .topping file to the topping fw volume always resulted in 'firmware damaged / unknown file' combo.
download the fw on a windows 10 pc and the update went without a hitch.

 

[SirD_P]

When it's in the FW Update mode can you just copy the firmware file to the TOPPING drive? I think that's all you need to do.

thanks for the quick response .. it turned out to be some weird macOS -> topping incompatibility .. copying the latest FW from a win10 pc to the topping fw volume/drive went without a hitch and the unit is on 2.02 now

 

[Music1969]

thanks for the quick response .. it turned out to be some weird macOS -> topping incompatibility .. copying the latest FW from a win10 pc to the topping fw volume/drive went without a hitch and the unit is on 2.02 now

Yes I had no luck on Mac

Worked first time on Windows for me

 

[Bleib]

Does it accept 5v input from Topping E70 DAC?
I may buy this to use mainly as a pre-amp to add a power-amp later on for larger speakers..

 

[marcom22]

Does it accept 5v input from Topping E70 DAC?
I may buy this to use mainly as a pre-amp to add a power-amp later on for larger speakers..

Yes

 

[Music1969]

What is max input voltage for this amp?

 

[staticV3]

What is max input voltage for this amp?

≥10.3Vrms.

The exact input clipping point is something that only @nagster measures, but he hasn't taken a look at the A70 Pro yet, so its unknown.

 

[shin08]

Hello,

I just made an account because I want to share some pictures of the interior of the a70pro.
I opened it out of curiosity, as I couldn't find any images online except those provided by Topping.

To remove the front panel, you will need a very long 2mm hex key (at least 150mm in length) because the screws are located on the back side of the panel.

Other than that, a normal 2mm hex or T8 torx screw would suffice to remove the screws visible outside the amplifier.

To remove the front panel, you have to thread the railing from the screw hole on the back using the hex key because you cannot force the board out through the back since the LCD panel and volume knob are connected via ribbons. I was lucky enough not to damage them!

They've hidden the screws on the back of the front panel in a sneaky manner. You can open and close the front panel by threading the hex key onto the screw holes on the back.

And here is what the inside of the amplifier looks like!

 

[Rhamnetin]

Thanks for that. I was looking at taking mine apart but upon seeing it's designed to discourage this, I decided against it. I figured it looks similar to the A90 inside and indeed it does. I wonder who makes those electrolytic caps? Not the green ones which must be Nichicon.

 

[shin08]

Thanks for that. I was looking at taking mine apart but upon seeing it's designed to discourage this, I decided against it. I figured it looks similar to the A90 inside and indeed it does. I wonder who makes those electrolytic caps? Not the green ones which must be Nichicon.

Yeah, I got lucky by not ripping the ribbons apart and had to scour online shops for that damn hex key.

The black caps are most likely from rubycon.

 

[nagster]

≥10.3Vrms.

The exact input clipping point is something that only @nagster measures, but he hasn't taken a look at the A70 Pro yet, so its unknown.

I've been curious about the A70pro ever since it was released. I'm looking for an excuse to buy one, but for some reason none of my TOPPING devices have broken so far...

I think the maximum allowed voltage for XLR input is 10.6V or less.　(Because it seems to have two 15V power supplies installed)
The RCA inputs may be similar, or 13.3V or higher(*) like the L70. (*AP Generator limitations)
If the RCA input impedance is 10kohm or more like A90D, I think the maximum allowable voltage is 10.6V or less.
In any case, it is sufficient for home use.
For professional use, the XLR input must be able to tolerate 12.3V (24dBu).

 

[PacketofCrisps]

...

but inside the box, A70Pro is the better buy for multiple technical reasons

...

Could you provide any more details on this ?

 

[Gymboy]

Hello,

I just made an account because I want to share some pictures of the interior of the a70pro.
I opened it out of curiosity, as I couldn't find any images online except those provided by Topping.

To remove the front panel, you will need a very long 2mm hex key (at least 150mm in length) because the screws are located on the back side of the panel.

View attachment 342380

Other than that, a normal 2mm hex or T8 torx screw would suffice to remove the screws visible outside the amplifier.

To remove the front panel, you have to thread the railing from the screw hole on the back using the hex key because you cannot force the board out through the back since the LCD panel and volume knob are connected via ribbons. I was lucky enough not to damage them!

They've hidden the screws on the back of the front panel in a sneaky manner. You can open and close the front panel by threading the hex key onto the screw holes on the back.

View attachment 342377 View attachment 342381 View attachment 342379 View attachment 342376

And here is what the inside of the amplifier looks like!

View attachment 342373

View attachment 342375

I am not electrical eng so I could understand all of this, but it looks very clean and masterfully done. Also good job on Tan Ku La modules, covering the secret sauce..