Poll for Topping PA5 owners only please.

[WileeCoyote]

All this emotion seems extreme to me. I don't know how anyone can know a reason or motivation for someone else doing anything without asking. This entire thread reads like a hate campaign.

The only reason I am writing this is because

1 - I can speak for myself
2 - I am bored

My reasons for purchase have nothing to do with SINAD. I don't know what that is or why it is important.

This is cost priced equipment, for the performance, targetted at a specific user base for high turnover. I do not expect the same QA as brands like Musical Fidelity, Cyrus, or Denon. I reached out to my local supplier and also Topping directly, voicing my concerns, and was re-assured by thier commitment to a local 1 yr warranty and an extended 1 yr manufacturer warranty. That's pretty good, better than most manufacturers where the norm. is only 1 yr.

I truly don't need an LA90. It's 3 times the price. That was tongue in cheek. Yeah it might fail but that's not as important to me as performance - at least during the warranty period. After 2 years, well, it was only AUD$550.

In my experience, if it lasts for 12 months on 24x7, it will last a lifetime. Time will tell.

By the way, power cycling is genereally not recommended for most transisitor circuits. Mine will be on 24x7

My primary decision to purchase was based on listening to online youtube reviews and hearing them comment. I dismissed those reviews that I thought were baseless and lacking cred, its easy to spot those. The reviews here were secondary - and justifying. I listened to the PA5 through their expensive speakers on my Sennheiser headphones (albeit their microphone). That told me volumes. What I looked for was zero noise floor, bass control, and detail.

I considered much more expensive ones, like Benchmark, LA90, and Chord. At its price point I felt that the power and detail from the PA5 could not be beat.

 

[restorer-john]

By the way, power cycling is genereally not recommended for most transisitor circuits. Mine will be on 24x7

Seriously, that is utter garbage and just makes me shake my head.

The PA5 has some serious design issues. More fool anyone who buys one, regardless if they are silly enough to think that leaving it on '24/7' is remotely clever.

 

[WileeCoyote]

Seriously, that is utter garbage and just makes me shake my head.

The PA5 has some serious design issues. More fool anyone who buys one, regardless if they are silly enough to think that leaving it on '24/7' is remotely clever.

Well that’s what I was taught. I just go with what the experts say…

https://www.researchgate.net/publication/348304765_A_Review_on_IGBT_Module_Failure_modes_and_Lifetime_Testing

I used to repair audio equipment and the most common faults were dry solder joins due to heat. Perhaps not all IGBTs are the same. In saying that it, it doesn’t apply to everything, since it looks like we are being ridiculously picky right now. The whole premise of class D is efficiency and not having a voltage and current at the same time. It is reasonable to expect these devices can handle power on continuously.

I’m not arguing reliability of these units, just what we should expect. And if failure occurs, well at a cost of about $1 a day over 2 years I’m happy to accept that risk for clean sound.

Now class A, AB etc is a different matter

 

[DanielT]

........... seems to be pointless SINAD chasing waaay past audibility ......

It is exaggerated this SINAD hunting regarding amplifiers. As an example, 0.1% distortion in an amplifier would probably seem too much BUT with an amplifier, with that level of distortion, put in a pair of speakers and these are praised. Praised, the speakers, that is BUT also then the amplifier, which is an active part of the speaker. :

Neumann KH420 Review (Studio Monitor)

This is a review and detailed measurements of the Neumann 3-way, active speaker (monitor). It is on loan from the company and costs US $5,195. Speaker was too heavy to lug to the loft where my main system is so you have to put up with the cell phone picture above and listening tests there. Back...

audiosciencereview.com

Incidentally, I think those Neumann KH420s seem really good and I don't care about 0.1% amp distortion as long as the amplifier is powerful enough (and not driven into clipping) and can handle the loads the speaker puts it through.

 

[Roland68]

Well that’s what I was taught. I just go with what the experts say…

https://www.researchgate.net/publication/348304765_A_Review_on_IGBT_Module_Failure_modes_and_Lifetime_Testing

I used to repair audio equipment and the most common faults were dry solder joins due to heat. Perhaps not all IGBTs are the same. In saying that it, it doesn’t apply to everything, since it looks like we are being ridiculously picky right now. The whole premise of class D is efficiency and not having a voltage and current at the same time. It is reasonable to expect these devices can handle power on continuously.

I’m not arguing reliability of these units, just what we should expect. And if failure occurs, well at a cost of about $1 a day over 2 years I’m happy to accept that risk for clean sound.

Now class A, AB etc is a different matter

Don't be mad at me, but maybe you need another expert...
This is an article for IGBT circuits in continuous industrial use, this is a completely different world. IGBT is about fast and, above all, high switching capacity of currents and voltages in the high 2, 3 and 4-digit range.

There are neither IGBTs nor conventional transistor circuits in the PA5.
Power cycling? In what context should this apply to the PA5? It certainly makes no sense to switch off such a device for a few minutes or an hour. But leaving it switched on unused for hours is absolutely pointless and only leads to premature aging of the components due to the permanent heating. This is much worse for a device than turning it on and off 1-2 times a day with such a low power.
That was different 20 years ago and is also to be viewed differently today when it comes to high power or short-term high peaks, but the PA5 and the switched-mode power supply are more in the lower toy range in terms of performance.

If switching on the PA5 or plugging the power supply into the socket (or switching on the power strip) actually leads to the failures, then that would be really ridiculous nowadays and owe a saving in the 1-digit $/€ range.
But with the PA5 I don't see any reason why it shouldn't last 10-20 years, other than maybe the main capacitor and switching power supply. But both could be exchanged easily and cheaply.
I will write more about the possible problems with the PA5 when I have taken a closer look at the circuit from.

 

[WileeCoyote]

Fair enough. If not IGBT then MOSETS? Switching has to occur somehow. Both are valid. Have not looked inside a PA5 myself.

 

[iLoveCats]

Guess who's PA5 is hissing in the right channel this morning? Now I need to decide if the LA90 is going to be enough power because I need that analog input, or buy another PA5

 

[Frank Sol]

Guess who's PA5 is hissing in the right channel this morning? Now I need to decide if the LA90 is going to be enough power because I need that analog input, or buy another PA5

IMO... Just my Opinion No way would I get another PA5

 

[Roland68]

Fair enough. If not IGBT then MOSETS? Switching has to occur somehow. Both are valid. Have not looked inside a PA5 myself.

Should be a few hundred transistors, capacitors, resistors, diodes, etc.
https://www.ti.com/product/TPA3251

 

[Roland68]

Guess who's PA5 is hissing in the right channel this morning? Now I need to decide if the LA90 is going to be enough power because I need that analog input, or buy another PA5

May I ask what exactly happened?
Does the right channel still play the music normally and does it hiss?
Or does it hiss even when no music is playing?
Does the volume of the hiss change with the volume control?

 

[delta76]

All this emotion seems extreme to me. I don't know how anyone can know a reason or motivation for someone else doing anything without asking. This entire thread reads like a hate campaign.

since when people speak out about their experience is a hate campaign?

 

[iLoveCats]

May I ask what exactly happened?
Does the right channel still play the music normally and does it hiss?
Or does it hiss even when no music is playing?
Does the volume of the hiss change with the volume control?

I get up really early and my house is super quiet and I heard a very light hiss when I walked up the stairs. My amp went to being on 24/7 a couple weeks ago. My DAC was off so no input to the amp. I turned my DAC on and streamed a radio station and it still plays. I did not think to adjust the volume on the amp to see if it changes the volume of the hiss. I flipped the input from A/B on the amp and nothing changed with the hiss all I heard was a tiny click.

 

[JeremyFife]

Guess who's PA5 is hissing in the right channel this morning? Now I need to decide if the LA90 is going to be enough power because I need that analog input, or buy another PA5

I'd be cautious going back to another PA5 while there is still risk of failure, and no definitive statement from Topping on whether the issue is fixed or not.

Plenty of alternatives for integrated amps with both analogue and digital input. Also, options for separate pre/power that don't cost as much as an LA90 but do deliver the watts. A lower measured performance won't make any audible difference.

Personally, if mine fails again I'll get an Audiophonics Hypex Ncore (MPA-S250NC XLR) power amp. If I didn't have my pre-amp I'd get something like a Yamaha AS501 and be done with it. Fingers crossed I don't have to though - I really like my PA5 now that it's working again.

Your call, but think it through

@TOPPING-Service

 

[airbornimal]

My amp went to being on 24/7 a couple weeks ago.

That's very similar to my experience. I started to leave the PA5 on and it started to hiss. Happened to both of my PA5s.

 

[anli]

My DAC was off so no input to the amp

I guess, at this case cables do work as antenna as far as DAC low output impedance doesn't shunt cables. Have you tried to detect noise hiss changing with PA5 volume reducing?

 

[Roland68]

A simple approach to a possible problem with the PA5.
The description of the error by almost all owners of a defective PA5 is striking.
- Noise, hiss or crackling on one or both channels
- Complete failure on one or both channels
- Failure or error occurs after 1500 to 3000 hours, especially when the PA5 is continuously powered on.

I know the first two phenomena from old amplifiers where the coupling capacitors (small electrolytes) have dried out. Something like this happens after 20-30 years, sometimes even after 10.

If I see that correctly, there are 4 pieces of Nichicon (U)FW 10uF/50v as coupling capacitors in front of the potentiometer and after the Topping D-01 Black Box.
Anyone who is familiar with heat dissipation in devices, components and heat sinks will quickly recognize that the 4 Nichicon (U)FW 10uF/50v are in a hot spot between the D-01 Black Box and the heat sink.
This will not be a problem in the first 1-3 hours after switching on (slight air circulation due to rising heat). But after a few hours, when all the components, board and case have reached their final temperature, these 4 capacitors should be the warmest spot in the device (apart from the TPA3251).
- Average lifetime of the Nichicon (U)FW approx. 2000 hours at 85°
- Smaller capacitances have a shorter service life at high temperatures
- With a range of 2.2 - 33,000uF, the 10uF is at the lower end of the service life
- The low load on these capacitors (only in the signal path, very low voltage) further reduces the service life at high temperatures
Under certain circumstances, these 4 coupling capacitors could then fail exactly after 1500 - 3000 hours of continuous operation.

If you have a defective PA5 and the corresponding possibilities, you could even measure it with a multimeter. 1,000 KHz tone at the input and measure this at the potentiometer and output coupling capacitor on the underside of the board.
Alternatively, 4 new capacitors could simply be soldered in parallel on the underside. if the PA5 then works again... However, then the guarantee is probably gone.

As I said, only one possibility or approach.
Another would reside in the D-01 Black Box.

 

[WileeCoyote]

Should be a few hundred transistors, capacitors, resistors, diodes, etc.
https://www.ti.com/product/TPA3251

MOSFET gates then

 

[WileeCoyote]

What are the first numbers of your serial number?

I'm on the 3rd PA5 (the first two had hiss and left channel issues after 3-4 months of use), with serial number starting with 220412. The other two (defective) were 211112 and 220112.

Audiophonics has been very compreensive with the issue (always sending me a new one after checking there was an issue with the PA5 I returned).

220612

Do you know what the number scheme means?

 

[restorer-john]

A simple approach to a possible problem with the PA5.
The description of the error by almost all owners of a defective PA5 is striking.
- Noise, hiss or crackling on one or both channels
- Complete failure on one or both channels
- Failure or error occurs after 1500 to 3000 hours, especially when the PA5 is continuously powered on.

I know the first two phenomena from old amplifiers where the coupling capacitors (small electrolytes) have dried out. Something like this happens after 20-30 years, sometimes even after 10.

If I see that correctly, there are 4 pieces of Nichicon (U)FW 10uF/50v as coupling capacitors in front of the potentiometer and after the Topping D-01 Black Box.
Anyone who is familiar with heat dissipation in devices, components and heat sinks will quickly recognize that the 4 Nichicon (U)FW 10uF/50v are in a hot spot between the D-01 Black Box and the heat sink.
This will not be a problem in the first 1-3 hours after switching on (slight air circulation due to rising heat). But after a few hours, when all the components, board and case have reached their final temperature, these 4 capacitors should be the warmest spot in the device (apart from the TPA3251).
- Average lifetime of the Nichicon (U)FW approx. 2000 hours at 85°
- Smaller capacitances have a shorter service life at high temperatures
- With a range of 2.2 - 33,000uF, the 10uF is at the lower end of the service life
- The low load on these capacitors (only in the signal path, very low voltage) further reduces the service life at high temperatures
Under certain circumstances, these 4 coupling capacitors could then fail exactly after 1500 - 3000 hours of continuous operation.

If you have a defective PA5 and the corresponding possibilities, you could even measure it with a multimeter. 1,000 KHz tone at the input and measure this at the potentiometer and output coupling capacitor on the underside of the board.
Alternatively, 4 new capacitors could simply be soldered in parallel on the underside. if the PA5 then works again... However, then the guarantee is probably gone.

As I said, only one possibility or approach.
Another would reside in the D-01 Black Box.

This is misinformation and messing around with replacing perfectly good capacitors is not going to solve anything.

The capacitors will not be the problem and capacitors do not fail after 2000-3000hrs at 85 degrees celscius.

see here:

Estimated Life Calculator for Capacitors | NICHICON CORPORATION

You will find information about Nichicon's estimated life calculator for capacitors here.

www.nichicon.co.jp

 

[restorer-john]

220612

Do you know what the number scheme means?

12th June 2022 most likely.