Topping PA5 Review (Amplifier)

[BoredErica]

Response from Topping:
"Thank you for your sharing. We already know this, and based on preliminary statistics, it is a low probability event. We are investigating the exact cause and we will deal with it and solve it as soon as possible."


Personally, I could not hear a difference unbalanced back when I ran it that way temporarily.

 

[antcollinet]

Response from Topping:
"Thank you for your sharing. We already know this, and based on preliminary statistics, it is a low probability event. We are investigating the exact cause and we will deal with it and solve it as soon as possible."


Personally, I could not hear a difference unbalanced back when I ran it that way temporarily.

Response to what?

 

[NTK]

Response to what?

I believe it is Topping's response to her inquiry regarding the problem with her PA5.

Topping PA5 Review (Amplifier)

I have not seen this issue, but I've only used the E50 with macOS and Linux. I have observed that, after a cold start, the E50 loses sync on USB for the first playback attempt. Subsequent playback attempts work fine. I'm seeing this behavior with Roon Bridge on macOS and Linux, but I've not...

www.audiosciencereview.com

 

[nagster]

Anyway, any recommendations for the converter? I had been planning on getting a Schiit SYS and Magnius and selling of my L30, but the Magnius is out of stock for another 6 weeks or so.

Three types of candidates. All are low price.

1: Recommended.
Nearly perfect. I want all SE output devices to be equipped with this as standard equipment.

2: OK.
(If something goes wrong, connect P1 and P2. R1 should be the same value as the output impedance.)

3: There is a sound.
(If something goes wrong, connect P1 and P2.)

 

[BoredErica]

Response to what?

As NTK said, my PA5 has some issues so I asked Topping about it. I hope they find the nature of the issue soon. I'd rather not have to send PA5s back and forth and would rather just wait until I can get a fixed unit.

The hiss and wind noise has seemed to changed into a lower frequency sound now. Sounds somewhat like farting honestly. And sometimes when I turn off the amp, wait 60 seconds, and turn it back on, the problem is gone for a while. Strange.

 

[ModDIY]

As NTK said, my PA5 has some issues so I asked Topping about it. I hope they find the nature of the issue soon. I'd rather not have to send PA5s back and forth and would rather just wait until I can get a fixed unit.

The hiss and wind noise has seemed to changed into a lower frequency sound now. Sounds somewhat like farting honestly. And sometimes when I turn off the amp, wait 60 seconds, and turn it back on, the problem is gone for a while. Strange.

I hope your next unit will be flawless.

 

[Nzama]

I hope your next unit will be flawless.

Should have never written first message here. My pa5 started random noise from both channels exactly as described ... Will write to audiophonics and request for a substitution... 2 weeks old :-(

 

[AudioArchitech]

I'm sure Topping is working hard to figure out the problem because this has to be affecting sales in a big way at this point

 

[mdsimon2]

I’m not sure they have a good track record of fixing problems. Look at the broken SPDIF inputs on their recent DACs.

Michael

 

[Deleted member 46664]

Three types of candidates. All are low price.

None of those is a truly balanced conversion...

A balanced signal has 2 equal signals in opposing polarities ....

From what we've gathered so far the PA5 does not have the facility to handle any kind of cable trickery. It actually needs both active signals to operate properly.

I've included the PDF schematic for a single ended to true balanced converter... the schematic has been built and tested and works quite well. Distortion is below my measuring ability, frequency response runs 2 hz to over 100khz, max output is the supply -2 volts. The gain pot gives plus or minus 10db from centre so you can level match your inputs.

There are ready made options you can order online, as well.

 

[AudioArchitech]

Not only will they loose sales, they likely already have many units that will get warrantied over and over

 

[Deleted member 46664]

Should have never written first message here. My pa5 started random noise from both channels exactly as described ... Will write to audiophonics and request for a substitution... 2 weeks old :-(

From what I can gather on the hissing noises, it's a power supply issue. The chip is happiest at 32 volts... not 38.

 

[pma]

IMO too fast design process and race for THD+N parameter, rather than designing for reliability. We call it a “hot potato”. It needs some experience to realize that reliability is the most important parameter.

 

[Nzama]

From what I can gather on the hissing noises, it's a power supply issue. The chip is happiest at 32 volts... not 38.

Thanks. Sorry for the dumb question, showing all my ignorance on class d chip, would that be reversible or chip has been damaged by 38v power supply already?
Agree with all other messages about impact of this issues, unfortunately it's a miss... Used to be perceived as high value for money.

 

[Deleted member 46664]

Thanks. Sorry for the dumb question, showing all my ignorance on class d chip, would that be reversible or chip has been damaged by 38v power supply already?

That would remain to be seen ... you can patch in a 32 volt supply and see what happens.

 

[pma]

How about irregular/random oscillations. Sometimes it is a real pain to find and fix them.

 

[Nzama]

That would remain to be seen ... you can patch in a 32 volt supply and see what happens.

Yet not really up to take the chance on my shoulders... I will update you in case but will look for a replacement first

 

[AudioArchitech]

I’m sure Topping would love it if you mess around with power supply… and void your warranty ; )

 

[Deleted member 46664]

Yet not really up to take the chance on my shoulders... I will update you in case but will look for a replacement first

Understandable ... But going down in voltage is pretty safe ... it's the other direction that is likely to cause problems.

 

[pma]

None of those is a truly balanced conversion...

A balanced signal has 2 equal signals in opposing polarities ....

If we wanted to be strict, the true balanced output must be floating. You may then tie one of the outputs to the ground and the second one will jump to the doubled voltage. This may be done by:
1) transformer
2) floating output like DRV134

Such circuit also has output CMR!!

But the consumer audio circuits are usually nothing more than a mere inversion at OUT-