Topping PA5 (TPA325X) : Is a modification worth it? ?

[Amplifier dude]

This is the graph that lends credence to the idea that it's actually a composite amp wrapped around the TPA3255. If you look at the Neurochrome charts, their composite amps also degrade at higher frequencies (although not quite to this degree) as you run out of loop gain. IF (and it's still to be verified from what I can tell) they have in fact made such a composite amp, I think it's a pretty interesting achievement.

Kept in context, I'd still say the performance is a notable achievement. Sure, this isn't something I'd choose over a Purifi, or even a Neurochrome, but in terms of off-the-shelf turnkey amps at anything close to the pricepoint, it's clearly a great performer.

Yes it’s slightly better than the $35 TPA3251 based Icepower 100AS2 module. Only the Icepower module uses much nicer parts, and a much cleaner board layout. Pictures of the TPA3255 based 200as1. Same power supply and PCB as the 100AS1 and 100AS2.

 

[daniboun]

Amir is personal friends with the Topping engineer. So it’s common for him to use flowery language when reviewing a Topping product.

I think the ASR review is pretty fair....
we can be friends and impartial, Amir wouldn't play with his credibility

 

[wushuliu]

So is this a thread promoting this product or do you have actual suggestions on how it can be modified for improvement?

 

[Amplifier dude]

If it was fair he would focus on the shortcomings, rather than downplay them and hype up what matters little, the 5w 1khz SINAD. If he was fair the de facto standard to judge amps would not be 5w 1khz SINAD, it would be THD+N vs power vs frequency over a 20-20k bandwidth. much like Purifi uses in their data sheet.

 

[daniboun]

If Im not wrong the THD+N vs frequency @20-20K has been shared in page 1

 

[Amplifier dude]

I missed this plot on Amir’s review. With the Purifi, Hypex and Benchmark amps overlaid in the background for direct comparison

 

[daniboun]

Let s talk about mod now.

I will start with the following, what would you think ?

OPTION 1 :
Replacing Rubycon 50V 2200uf > Mundorf MLGO 63V 2200 / 3300 uF (Total 13.5 euros)
Replacing 2x Nichicon FW 50V 220uf > NICHICON KW 50V 220uf (Total : 2 euros)
Replacing 8x Nichicon FW 50V 10uf >NICHICON KW 50V 10uf (Total 8 euros)

OPTION 2 :
Replacing Rubycon 50V 2200uf > Nichicon KG gold Tune 50V 2200uf (Total 5 euros)
Replacing 2x Nichicon FW 50V 220uf > Elna Silmic II 50V 220uf (Total : 5 euros)
Replacing 8x Nichicon FW 50V 10uf > Elna Silmic II 50V 10uf (Total 6 euros)

OPTION 3 :
Replacing Rubycon 50V 2200uf > Toshin Kogyo série UTSJ 50V 2200uf (Total 9 euros)
Replacing 2x Nichicon FW 50V 220uf > Toshin Kogyo série UTSJ 50V 220uf (Total : 7 euros)
Replacing 8x Nichicon FW 50V 10uf >Toshin Kogyo série UTSJ 50V 10uf (Total 8 euros)

More complicated :
Replacing CoilCraft SER2915H-103KL (10uf / 18A) > by 4X Air Core Customs same spec. (Total : Search in progress.)

Any input is welcome )

 

[Amplifier dude]

What are you expecting these mods to accomplish?

 

[daniboun]

Probably like in all mods, the pleasure of testing, improving, sharing a passion with a community. And if you answer me that what cannot be measured, does not make any sense ... then I would answer: that I can always share my impressions, however subjective they may be)

In this case, we know that the PA5 sounds great ouf of the box. But replacing average caps by some Audio Grade caps, with the same values, could improve your sound experience. It makes me remember this thread :

JLE TPA3255 Build and Modifications



You can read this as well :

AES Paper Digest: Audio Capacitors. Myth or reality? | Audio Science Review (ASR) Forum

 

[Amplifier dude]

Caps can make a difference in sound. But resistors are even more important. However I wouldn’t mess with the inductors without an audio analyzer.

 

[daniboun]

Caps can make a difference in sound. But resistors are even more important. However I wouldn’t mess with the inductors without an audio analyzer.

I will probably start with the basic updates.
I won't upgrade the inductors now.

 

[TNT]

I missed this plot on Amir’s review. With the Purifi, Hypex and Benchmark amps overlaid in the background for direct comparison

Don't se the overlay... or?

//

 

[TNT]

...
In this case, we know that the PA5 sounds great ouf of the box. ....]

Eee, how do "we" know this?

//

 

[daniboun]

Eee, how do "we" know this?

I meant : measures well out of the box ) I will share my impressions asap anyway )

 

[daniboun]

OK guys,

Seems that the caps update is not so easy ) If I check the size of the stock caps :

Rubycon 50V 2200uf size = 18mm (D) x 35,5mm

Nichicon FW Series 50V - 220uf = 10mm (D) x 12,5mm

Nichicon FW 50V 10uf = 5mm (D)x 11mm


Looking for Audio grade caps with these diameters is not so simply ! Elna Silmic II, Nichicon KW seem not to have the same diameters... Any help here ?
In my opinion, we'll have to make a choice by elimination at some point)


Ex :

Nichicon FG Fine Gold 10uf – 50v = OK (10mm x 12,5mm)
Nichicon FW Series 3300uf – 50v = OK (18mm x 35mm)
Nichicon FG Fine Gold 220uf – 50v = 12,5mm x 20mm
Nichicon KW Series 2200uf – 50v = 16mm x 35,5mm
Elna Silmic II 10uf – 50v = 8mm X 11.5mm
etc

 

[TNT]

Get a 2:nd unit. Modify one of them. Do a proper, documented, blind test (ask someone to change units - random series of 16 changes) and prove that you can hear a difference.

Due to your constant posting of "boutique" mods, I think you owe to the audience that you yourself can really hear the difference. I'm sure your "feel" they are good but... Looking at your system from pics you posted, I doubt it. It simple don't seem to be up to the resolving level to begin with - if it is indeed even possible.

You are now just using the word "modifying" to continue posting product news - for some reason which is hard to understand. You have been criticised for this before...

Will you in the future create a new thread for every released product and ask if changing capacitors might be a good thing... or?

//

 

[Yatsushiro]

That’s just thermal paste residue on the TPA chip.

I don't mean the thermal paste, I meant the black redactions (photoshop?) covering up certain areas of the board, for example the 2 black rectangles visible along the lower part of the PCB here:

 

[daniboun]

Hi amigo

As told you : these pictures are the very first from ASR.(black squares hide serial numbers or other identifying text.) In my humble opinion this is one of the first version on the market. There is a great chance that mass productions may have slightly different components ....

I will share the ones of my amp as soon as I can.

 

[daniboun]

Get a 2:nd unit. Modify one of them. Do a proper, documented, blind test (ask someone to change units - random series of 16 changes) and prove that you can hear a difference.

Due to your constant posting of "boutique" mods, I think you owe to the audience that you yourself can really hear the difference. I'm sure your "feel" they are good but... Looking at your system from pics you posted, I doubt it. It simple don't seem to be up to the resolving level to begin with - if it is indeed even possible.

You are now just using the word "modifying" to continue posting product news - for some reason which is hard to understand. You have been criticised for this before...

Will you in the future create a new thread for every released product and ask if changing capacitors might be a good thing... or?

//

I have friends on this forum but not only ... and just like in real life: you have to sort it out) You have the right to have a judgment, however it is not necessarily true.

If you want to contribute positively to this thread, with pleasure

 

[maty tinman]

Talking about Mundorf MLGO caps, Cresnet / MicroAudio use them now in its SMPS.

MicroAudio – SMPS for audio applications
Products – MicroAudio


I have a DC Blocker with two MLGO 25V 47.000 uF and the sound is better (and with more bass) than before with two EPCOS 18.000 uF. You know, I have a very noisy grid at home.