Topping PA5 II Stereo Amplifier Review

[stefanovesa]

Thanks all.

Do you know if I can connect at the same time single ended and balanced input, so I can switch between two sources, e.g a phono pre and a DAC? No mention in the manual

 

[staticV3]

Do you know if I can connect at the same time single ended and balanced input, so I can switch between two sources, e.g a phono pre and a DAC?

Yes, that's fine.

 

[john11]

It's generally a good idea to solder small film caps on the underside of big aluminium electrolytics. There's a few caps here just underneath the input module and also some to its left, is it worth a try ? I don't know what's in the modules as they are potted

Since the module is potted i can't see what's in it, could i solder

 

[Roland68]

It's generally a good idea to solder small film caps on the underside of big aluminium electrolytics. There's a few caps here just underneath the input module and also some to its left, is it worth a try ? I don't know what's in the modules as they are potted

View attachment 402195
Since the module is potted i can't see what's in it, could i solder

No, in general that is not a good idea, but a stupid one.
Without knowing the circuit exactly and knowing what you are doing, and especially why you are doing it, it is absolutely pointless.
The modules contain the complete and complex circuitry of the OPAs that are attached in front of them.

If that sounds a little harsh, then it is because I have often had such tuning orgies on my table from inexperienced tuners and the device was at best not much worse.
The PA5 II is very well developed and the circuit has already been taken to the extreme, there is no room for any kind of trial and error tuning.

If you really know your way around this area, then you also know that there is no room for the required component quality either on or under the board. And the last thing the PA5 II needs is some kind of antenna in the form of long connection cables for components.

If you need something to play with, then get one of the cheap TPA3255 boards from Aliexpress, there are dozens of page-long threads for modding on ASR and diyaudio. But don't think that such modding will come anywhere close to a PA5 II, no matter how expensive or complex the tuning is.

 

[Killingbeans]

It's generally a good idea to solder small film caps on the underside of big aluminium electrolytics.

It's generally a bad idea to do any kind of modification of electronics without first defining precisely what the modification is supposed to accomplish, and then do measurements to verify that said change in behaviour is actually accomplished.

 

[Julf]

It's generally a bad idea to do any kind of modification of electronics without first defining precisely what the modification is supposed to accomplish, and then do measurements to verify that said change in behaviour is actually accomplished.

Yes and no. As long as the modification is harmless (does not affect the audio quality or reliability too much), it will result in a perceived improvement in sound quality - just because the listener believes it will.

 

[Ahmonge]

If the goal is improving HIFI devices by some miraculous add-ons, there are harmless alternatives, like stickers:

Quantum Sticker - Telos Audio Design

Jeff Lin is the operator and owner of Telos Quantum technique.

telos-audio.com.tw

 

[john11]

If the goal is improving HIFI devices by some miraculous add-ons, there are harmless alternatives, like stickers:

Quantum Sticker - Telos Audio Design

Jeff Lin is the operator and owner of Telos Quantum technique.

telos-audio.com.tw

May I please have some stickers

 

[Roland68]

May I please have some stickers

You can order 20 stickers on Ebay for the bargain price of €115.
Each sticker is only a few mm big (or small ;o) and you should definitely note that the warranty period is only one year.
And they assume no liability whatsoever for anything...

 

[Ropeburn]

You can order 20 stickers on Ebay for the bargain price of €115.
Each sticker is only a few mm big (or small ;o) and you should definitely note that the warranty period is only one year.
And they assume no liability whatsoever for anything...

I'm sceptical. For now, I'll stick to those good old "hi res audio" stickers for improving sound.

 

[Roland68]

I'm sceptical. For now, I'll stick to those good old "hi res audio" stickers for improving sound.

I could offer you cryo treatment, ion bombardment and high voltage treatment for your stickers.
I also have high temperature treatment at 1400° or 2100° degrees in my program, but I cannot accept any liability for this with the stickers.

 

[john11]

You can order 20 stickers on Ebay for the bargain price of €115.
Each sticker is only a few mm big (or small ;o) and you should definitely note that the warranty period is only one year.
And they assume no liability whatsoever for anything...

Do you have any frequency response graphs or THD measurements to show the effectiveness or improvements these stickers have on the sound
Have you done any listening tests, blind or otherwise, the volume control must be the same to ensure fairness

 

[JeremyFife]

It's generally a good idea to solder small film caps on the underside of big aluminium electrolytics. There's a few caps here just underneath the input module and also some to its left, is it worth a try ? I don't know what's in the modules as they are potted

View attachment 402195
Since the module is potted i can't see what's in it, could i solder

How can it be a good idea to change (solder additional caps) to a circuit when you don't know what the circuit is??

Your Amp, your time ... just listen to music instead!

 

[john11]

You can order 20 stickers on Ebay for the bargain price of €115.
Each sticker is only a few mm big (or small ;o) and you should definitely note that the warranty period is only one year.
And they assume no liability whatsoever for anything...

What is the burn in time for these stickers before they sound at their best

 

[Mort]

Underlighting also makes it more hi-fi.

 

[john11]

I could offer you cryo treatment, ion bombardment and high voltage treatment for your stickers.
I also have high temperature treatment at 1400° or 2100° degrees in my program, but I cannot accept any liability for this with the stickers.

What would be the price for the standard version, and the audiophile version with go faster stripes and the words " Pro Studio Mega Upgrade Amazing Sound " added

 

[john11]

Underlighting also makes it more hi-fi.
View attachment 402440

Would using oxygen free, silver plated, sheilded, teflon jacketed, mains cable improve the luminance quality of lighting, or would battery powered be better as the voltage is smoother with less spikes and should more consistent and enjoyable

 

[Ahmonge]

What is the burn in time for these stickers before they sound at their best

The time given by the store to return them plus 20 hours

 

[SoNic]

It's generally a good idea to solder small film caps on the underside of big aluminium electrolytics. There's a few caps here just underneath the input module and also some to its left, is it worth a try ? I don't know what's in the modules as they are potted

View attachment 402195
Since the module is potted i can't see what's in it, could i solder

Take a picture that shows the OpAms above those modules, and the underside of that board too.
I wonder if it's a PFFB network inside those.

https://www.ti.com/lit/an/slaa788a/slaa788a.pdf

I think too that bypass capacitors are always required over electrolytic ones in power stages, maybe they already have some, closer to the OpAmps power pins.

LE: Yes the potted section is the PFFB passive network, see here

Topping PA5 II Stereo Amplifier Review

Driving a pair of Revel M16s in a room 5m x 3m, would the plus version of this be necessary, or would the cheaper, vanilla version be fine? Thanks. I think the cheaper PA5 II will be fine for that size listening space.

audiosciencereview.com

I don't know why is so secret, since TI paper from above gives all the component values needed.

 

[MediumRare]

OK, I'm gonna say it: Rolling OP Amps - or any modification whatsoever - of this amp is the dumbest idea I've ever heard. Below 62 watts this amp is absolutely transparent. You cannot hear any flaws whatsoever. You probably can't even measure any flaws at -110 dB SINAD. So the idea you can possibly improve it is simply fanciful. I'm all for DIY as a learning experience, but unless you want to learn about wasting your time and possibly damaging the amp with less-than-perfect solders... you'll be wasting your time and risking your amp.