Topping PA5 II Stereo Amplifier Review

[Kevinfc]

Any link with reliable measurements ?
I saw that the new model (July 2022) is now using a fully differential chain + PFFB enabled.
For 220W/4R you will need a solid 48V PSU

For a finished amp count about $ 400 with an aluminium case. + good Connex PSU Meanwell / Morsun + connectors etc

I’d love to see a technical review of this board as well. I have all the necessary parts to complete a TP3255 amp, just wondering which is the right board.

 

[TheLastGerman]

Got my PA5 II today. First Impressions (DAC: Topping DM7 / Speakers: Magnepan MG 1.6/QR SE): Very precise, open sound. Gain is on the low side. DC offset -17.9 resp. +27.8 mV. Very moderate warming. I'm pleased so far ...

I'll attempt to open it soon and post some pictures of the guts.

Maybe some of you are interested in this:

Here are the black boxes - after your brand new PA5 II has exploded without any comprehensible reason, you may send at least one of these to China for investigations.

They are attached from the bottom with a lot of soldering points, so there is a good chance that they can still be found in their original place even after the explosion. Very forward thinking!

 

[jdjung]

Someone posted photos a while back on the first page. https://www.audiosciencereview.com/...s/ask-me-questions.46113/page-17#post-1681455

I ordered mine on Amazon and will run the heck out of it to make sure it's reliable, while I'm present. Someone a few posts back said you can't use an unbalanced source with this device, that it will heat up? Is this correct?

 

[jdjung]

LOL I posted 3 minutes to late. Haha!

 

[TheLastGerman]

Someone posted photos a while back on the first page. https://www.audiosciencereview.com/...s/ask-me-questions.46113/page-17#post-1681455

I ordered mine on Amazon and will run the heck out of it to make sure it's reliable, while I'm present. Someone a few posts back said you can't use an unbalanced source with this device, that it will heat up? Is this correct?

Oh, I had overlooked that. Then I could have saved myself the trouble ...

 

[Sokel]

Maybe some of you are interested in this:

View attachment 307796
View attachment 307797View attachment 307798View attachment 307799View attachment 307800View attachment 307801View attachment 307802

Here are the black boxes - after your brand new PA5 II has exploded without any comprehensible reason, you may send at least one of these to China for investigations.

View attachment 307805

They are attached from the bottom with a lot of soldering points, so there is a good chance that they can still be found in their original place even after the explosion. Very forward thinking!

View attachment 307806

Last picture's flux lake does not exactly shouts quality.
And looks like an after-job.Repair or last minute's change of the famous potted modules?

 

[ampguy]

Someone posted photos a while back on the first page. https://www.audiosciencereview.com/...s/ask-me-questions.46113/page-17#post-1681455

I ordered mine on Amazon and will run the heck out of it to make sure it's reliable, while I'm present. Someone a few posts back said you can't use an unbalanced source with this device, that it will heat up? Is this correct?

The PA5 II has SE unbalanced input on one of the 2 input pair. Use that input for unbalanced sources, and you should be fine.

 

[howard416]

Last picture's flux lake does not exactly shouts quality.
And looks like an after-job.Repair or last minute's change of the famous potted modules?

Yeah, the manual soldering certainly leaves something to be desired.

 

[Sokel]

Yeah, the manual soldering certainly leaves something to be desired.

I don't consider myself any good on soldering (even if I have soldered my fair share of smd's ) but at least I have one of these:

 

[MCH]

Maybe some of you are interested in this:

View attachment 307796

question for the experts, as i am currently working on a diy device and am curious: i see they use a 12 conductor (ca. 0.5 pitch?) ribbon cable for the line signals using only alternate conductors. Is this a good practice? the non used conductors better grounded or floating? thanks and sorry for out of topic but wanted to take the chance to learn something.

 

[TheLastGerman]

question for the experts, as i am currently working on a diy device and am curious: i see they use a 12 conductor (ca. 0.5 pitch?) ribbon cable for the line signals using only alternate conductors. Is this a good practice? the non used conductors better grounded or floating? thanks and sorry for out of topic but wanted to take the chance to learn something.

Return paths should always run as close as possible to the signal path to achieve the smallest possible loop area. Parallel signal paths should be separated by a ground conductor to avoid crosstalk.
The twelve ribbon cable conductors in the PA5 II are a good example of such a scheme and would ideally be connected like this:

1 - balanced "hot"
2 - ground
3 - balanced "cold"
4 - ground
5-8 as before
9 - unbalanced "hot"
10 - ground
11-12 as 9-10, whereby 12 can remain floating as there is no further signal-carrying conductor.

 

[JeremyFife]

Here is my .02 opinion - Topping made a fine amp with the original PA5, but they did not document it well. Users did not know the speaker negative is not referenced to earth ground, and the tiny speaker wire holes for 16ga or smaller wire caused many issues. They also did not initially tell users to use balanced inputs only initially. Users used transformerless rca unbalanced adapters to use with the amp which gave little gain, thus foolish users left the volume cranked and wondered why it overheated. They sort of fixed it by providing one input with unbalanced RCA, and hopefully have better heat dissipation, but the v ii is simply inferior to the original PA5.

Choose to disagree.
The PA5 had a design flaw - confirmed here by Topping - it was a bad design.
Jury is out on the PA5 II. I have no axe to grind and I hope the reported failure here is a one-off.
Time will tell, but I wouldn't buy until more time has passed

 

[antcollinet]

You're right,and that also raises the test factor.
Testing stuff under every possible condition must take some time and the new market ethics are not very kind to it.

In my former life, our test program would average around 6 months, with 10 test engineers. Part of that test program involved putting a significant number of test units on full load testing for the full duration of the program.

 

[antcollinet]

Last picture's flux lake does not exactly shouts quality.
And looks like an after-job.Repair or last minute's change of the famous potted modules?

I'm wondering if htey are hand soldering those components by default. Possibly the pin density is causing them problems for a wave solder process. (Very small clearance between the solder pads could be resulting in bridging)

Flux residue should be cleaned off though.

 

[Lräk]

Maybe some of you are interested in this:

View attachment 307796
View attachment 307797View attachment 307798View attachment 307799View attachment 307800View attachment 307801View attachment 307802

Here are the black boxes - after your brand new PA5 II has exploded without any comprehensible reason, you may send at least one of these to China for investigations.

View attachment 307805

They are attached from the bottom with a lot of soldering points, so there is a good chance that they can still be found in their original place even after the explosion. Very forward thinking!

View attachment 307806

Nice job on the pics. I did similar on the original PA5, but not nearly as good as yours.

 

[DMan2323]

Others who have purchased these products and had to go through the issues of the product dying on them can provide more details. I'm going off what I've read reported here and some other audio sites.

I've read issues with PA5, LA90D, A90, E30, and A30Pro. Typically users report a popping or crackling noise before the unit dies. Read one about the unit smoking. Read an account about the poor internal quality (poor soldering, etc.) of one. Have read many accounts about the difficulty in getting in touch with Topping. Apparently to get them fixed you have to mail them to China. Have read several accounts of users getting multiple units that failed. Apparently even though Topping admitted the design flaw in the PA5, they did not recall the unit and kept selling it for a period of time afterwards before discontinuing it. Basically the company seems like a mess. They put out unreliable products, and then they offer poor customer support when it happens.

I think the biggest thing that perplexes
me after these things have been reported is that people still buy them. If nothing else, aren't people worried about the safety issues of a piece of failing electronics? That can have serious consequences. I suppose if you have the technical acumen to take the product apart and repair it yourself, then this may not be a big concern, but how many of you on here can really do so? If you can, are you? Do you really want to have to do so? Isn't it reasonable to expect a safe and reliable product?

Astrofly, a much appreciated & detailed reply. Will of course perform any personal due diligence but that's exactly what I was seeking I owe you.

 

[Astrofly]

Astrofly, a much appreciated & detailed reply. Will of course perform any personal due diligence but that's exactly what I was seeking I owe you.

I'm glad it was helpful.

 

[AltoVariago]

I had two LA90D dead within one months. Their customer service is okay if you are in China but if you locate outside of China, Good Luck with that. I carried those two amps back to China and had them during the summer. Haven't noticed any problems since that. Those two amps weight 20KG, so if you want to have them shipped to China, the shipping cost will be crazy.

What is surprising me is that people keep buying these equipments.

 

[Lräk]

Someone posted photos a while back on the first page. https://www.audiosciencereview.com/...s/ask-me-questions.46113/page-17#post-1681455

I ordered mine on Amazon and will run the heck out of it to make sure it's reliable, while I'm present. Someone a few posts back said you can't use an unbalanced source with this device, that it will heat up? Is this correct?

Photos not nearly as plentiful and nice as @TheLastGerman 's photos.

I've spent 1 to 2 hours each day with my new PA5 II at fairly high volume (loud enough to piss off the wife). It's a bit warm our here (85 degree F) and the PA5 II gets pretty warm to the touch. I don't remember the PA5 getting that warm. There are at least 2 extra IC's on the PA5 II that shouldn't add that much heat. Still sounds great though.

As far as SE (unbalanced source), I believe someone said that about the PA5 and not the II. I actually tried unbalanced a few times just out of curiosity and never had a problem other than the volume was 6db down which is why the II added the gain on the SE port.

 

[audiotron]

Just ordered the plus. Thanks for the review.