Poll for Topping PA5 owners only please.

[dsnyder0cnn]

These little mini-amps with the external supplies (and even some with internal supplies) are not intended to be turned off and started back up repeatedly. The power supply should be plugged into a live outlet and left on all the time. The amp itself is also always on, but when "off" from it's power switch it is in a deep standby mode.

The reason for this is the large reservoir "Bulk" capacitors used on the amplifier boards and, often, in the power supply as well. When you first connect the Power cord to the supply there is a rather large inrush of current until it gets charged up and working. When you first connect the amp to the power supply there is another large inrush of current while the amp's big caps charge up and settle down. When you power cycle with both devices connected that inrush can be big enough to do damage.

Neither device is likely to be designed to handle this repeatedly. Each repetition puts a very large strain on the rectifier diodes and AC filters in the power supply. Each time causes some trivial amount of damage, until one day it starts acting up and eventually dies.

This issue came to the fore with people shutting down their PCs and then turning off the "babysitter switch" on the back of the case. We had a large rash of failed power supplies because the current inrush was popping the rectifiers inside. We ended up replacing quite a few under warranty and advising that the power switch be left on all the time. After that, very few supply failures.

So .... best advice... to avoid the "inrush" problem, hook up your mini-amp, plug it into a live outlet... and leave it "on" all the time. When not in use, use the "on-off" switch on the amplifier to put it into standby mode.

Ah. Precisely what I've been doing for both the PA5 and (after seeing it in "blinking white power LED mode" once) the L50. I suppose this should be obvious, but it would be nice if Topping added this to their diminutive instruction manuals…ideally on the first page.

 

[Deleted member 46664]

Ah. Precisely what I've been doing for both the PA5 and (after seeing it in "blinking white power LED mode" once) the L50. I suppose this should be obvious, but it would be nice if Topping added this to their diminutive instruction manuals…ideally on the first page.

Thing is that it's not obvious. In fact it's rather counter intuitive since the perception is that it's not really off at all.
I took a few minutes today and measured the idle current in my Ayima A07 while in the AC on Amp off condition. The amp itself draws only about 20ma of idle current. The power supply is basically static, just doing "station keeping" to keep the voltage even. Total draw from AC is about the same as an LED night light.

Some have made points about the environment with 10s of thousands of devices like this idling world wide. I would argue that is better than thousands of "dead" power bricks hitting the garbage cans because of "sudden inrush death syndrome".

But think about this ... we all use our remote controls to turn things off and on. In order for that to work the TV or AMP has to have some power in it all the time, to see the remote with. So it's not just these mini amps that are only half off... it's almost everything... even your microwave is drawing some power to keep the clock running.

The reason this is a problem in mini-amps and like equipment is that A) most power bricks are not engineered to handle large inrushes of current and B) these amplifiers with their huge bulk capacitors pose an unusual load.

 

[Ellisr63]

My PA5s are working fine so far.

 

[dsnyder0cnn]

The manual does explicitly say to turn the amp off before unplugging the supply, so if you are running it from an auto-off/anti-vampire strip, I would make sure to turn it off manually before the strip does. Since I forget all the time, I plugged the power supply into an always on outlet.

Could it really be that simple? I hope so…

 

[B8S4]

How come a Topping rep is nowhere to be found? It appears the company couldn’t care less.

 

[dsnyder0cnn]

How come a Topping rep is nowhere to be found? It appears the company couldn’t care less.

I've (thankfully) not had any problems with mine so far, but if I did, I'd be ringing up the place from which I purchased it (Apos, in my case). I would not expect company reps to be watching this forum and proactive opening support cases based on feedback or experiences documented here.

 

[REK2575]

I've (thankfully) not had any problems with mine so far, but if I did, I'd be ringing up the place from which I purchased it (Apos, in my case). I would not expect company reps to be watching this forum and proactive opening support cases based on feedback or experiences documented here.

I take your point, but don't you find it a little telling that @JohnYang has disappeared completely from the PA5 Review thread? I understand Topping's focus is on the LA90 now, and that he is appearing in that thread. But the PA5 is still a relatively new product for Topping, and I'd think that amid the multiplying reports of unit failure he or someone from Topping would be on hand to say *something* about the reported problems. It would give at least some reassurance that Topping acknowledges the problems and is looking for a solution.

last post from @JohnYang re: PA5 in December...

 

[wlgreg]

I've (thankfully) not had any problems with mine so far, but if I did, I'd be ringing up the place from which I purchased it (Apos, in my case). I would not expect company reps to be watching this forum and proactive opening support cases based on feedback or experiences documented here.

Generally agree about expectations for company reps. I certainly wouldn't expect reps from every manufcturer who gets reviewed here to monitor forums and engage with users.

In Topping's case, however, John's previous activity engaging with the community has set a different expectation. He's been a *very* active participant in these forums, repeatedly engaging in numeorus threads, and going so far as to give customers specific advice about what's OK to do under Topping warranty terms (like opening up a PA5 to tighten speaker posts).

That said, if he no longer intends to engage, that's fine and certainly his (and Topping's) prerogative. It would, however, be nice to know if that were the case (otherwise the continued lack of response here is somewhat puzzling).

Just my $0.02.

 

[Deleted member 46664]

Could it really be that simple? I hope so…

On or Off won't mitigate the current inrush when the AC is turned back on. All the bulk capacitors are still connected to the supply and they are still going to draw large currents during initial charging.

 

[Frank Sol]

'Problems' with 1 outta 4 is terrible for Topping

 

[antcollinet]

'Problems' with 1 outta 4 is terrible for Topping

1 out of 4 in a self selecting (hence not random) survey. However, even so it is not a good result.

 

[dsnyder0cnn]

'Problems' with 1 outta 4 is terrible for Topping

I suspect that folks with no PA5 issues are underrepresented in this survey. To what extent is impossible to say.

 

[Fleuch]

changed my vote. just now started hearing crackling in my left channel

i don't think i'm buying a Topping product ever again. pointless SINAD chasing while compromising build quality does not a good product maket a consistent left-channel issue?

Where a PA5 has failed, is it a consistent left-channel issue?

Serial number #2201, not a problem at the moment.

 

[Frank Sol]

I suspect that folks with no PA5 issues are underrepresented in this survey. To what extent is impossible to say.

Just guessing here... As a subset (ASR members) vs general audio community... Much larger % of ASR members own PA5

Regardless if that ^ means anything... I hope Topping works out something for people having issues

 

[Colonel7]

Just guessing here... As a subset (ASR members) vs general audio community... Much larger % of ASR members own PA5

Regardless if that ^ means anything... I hope Topping works out something for people having issues

I agree with you on ASR membership ownership and first adopters of the best measuring Topping gear. I view the early reports of failure more like a fractal than anecdote.

 

[REK2575]

Agree that 'percentage of defective units' may indeed be overrepresented in this poll. But regardless, it would be nice to get some official acknowledgement from Topping or JohnYang that there is a problem. It's not like ASR isn't on their radar! The failure rate of the PA5 may not be as high as 25%, but clearly, it's not a negligible percentage either, based on all the reports showing up here.

 

[pma]

The failure rate of the PA5 may not be as high as 25%,

Anything above some 3% is not good.

 

[Selkirks]

JohnYang posts on page 2 of the LA90 review but offers no comments regarding PA5 issues on the other threads.

Hmmm...

I hope they are at least working on the issue.

 

[raest]

Where a PA5 has failed, is it a consistent left-channel issue?

Serial number #2201, not a problem at the moment.

dunno if it is consistent, but the reports i've read in the other thread were either left or both channels. mine is currently left channel only

for reference, it was always plugged in, used only the front switch to turn it "off" overnight. it has very very rarely played over 25% volume. it was fed a balanced signal from Topping's own E50 connected by Topping's own TRS 25cm interconnects. up until today, it was always connected on In2 (as it is neater for the interconnect on the e50, stacked below the PA5). it was powering a pair of KEF R7s (88db sensitivity, 8ohm nominal, 3.2 minimum). it was often warm (nearly always), but never uncomfortably so (eyeballing, in the 35-40C range)

i wonder if it might be related to speaker loads? according to KEF's specs, the R7s is under 4ohm between cca 75-250Hz, maybe that's too much for the PA5? it shouldn't as specs would indicate otherwise, as it's rated down to 2ohms. dunno, just thinking out loud

what are or were you guys/gals powering with it?

 

[jjmanda]

Had mine since late December. Serial number in the 2010 range. No problems experienced.
Signal chain is Gustard X16 to Topping Pre90 to PA5 all with proper cables.
I use it to power Satori ARA BE's which are rated at a nominal 4 ohm.

I always turn off using the front power toggle switch before I power everything down.

I took the PA5 out for about a week or so, but it's back in and doing fine.