Topping PA5 measurements )

[daniboun]

It is unlikely that the power chip will be seen if it is protected in this way.
View attachment 167811

Not sure this is the Audio chip in the picture....In my opinion, disassembling the case will be worth more than any guess)

 

[daniboun]

"Power input: DC38V/4.0A"

"Output Power:
140W×2@4Ω THD+N<10%
125W×2@4Ω THD+N<1%
85W×2@8Ω THD+N<10%
65W×2@8Ω THD+N<1%
"

It's a joke??

PSU is about 152W.... theoretically we hardly had to get around 100W / 4R
for the spec... they come from Audiophonics.... All is marketing as usually )

But as I previously said, this amp is clearly a desktop amplifier and not power oriented one.

 

[daniboun]

You mean okay measurements below 60W?

@80W/ 4R and 50W/ 8R

I'm not sure the average person listens at more than 50W ... So the measurements remain excellent)

 

[ModDIY]

PSU is about 152W.... theoretically we hardly had to get around 100W / 4R
for the spec... they come from Audiophonics.... All is marketing as usually )

But as I previously said, this amp is clearly a desktop amplifier and not power oriented one.

The question is not there. The manufacturer Topping announces powers which are false if we take into account the SMPS , it is not serious, it is not for us to judge if the listening power for an office is sufficient.

In power measurements, this amplifier will not be able to provide the power INDICATED in the specifications.

I am very disappointed with Topping.

 

[Matias]

The question is not there. The manufacturer Topping announces powers which are false if we take into account the SMPS , it is not serious, it is not for us to judge if the listening power for an office is sufficient.

In power measurements, this amplifier will not be able to provide the power INDICATED in the specifications.

I am very disappointed with Topping.

What do you mean false? It was published here the power x THD+N in 4 ohms. Obviously they used the included power supply. Don't be so fast do discredit them, they have been honest about their specs and publishing measurements all along.

 

[JohnYang1997]

The spec'd output power is measured with both channel driven using the included power supply.

 

[daniboun]

The question is not there. The manufacturer Topping announces powers which are false if we take into account the SMPS , it is not serious, it is not for us to judge if the listening power for an office is sufficient.

In power measurements, this amplifier will not be able to provide the power INDICATED in the specifications.

I am very disappointed with Topping.

This shocks me less than hiding the chips used. I would have preferred Topping to be transparent about the technology used rather

 

[ModDIY]

The spec'd output power is measured with both channel driven using the included power supply.

Thank you for that clarification. It is true that an SMPS has a margin of power.

 

[JPrufrk]

@JohnYang1997 thank you. It's cool that you participate directly here. I don't get one thing, and I'm sure I'm missing something very basic, and am hoping that you can explain it here for me and perhaps others. 38V@4A = 152W. Even assuming 100% efficiency, how can an amplifier powered by this supply put out more than 152/2 = 76W per channel? Thanks in advance.

 

[filipduarte]

@JohnYang1997 thank you. It's cool that you participate directly here. I don't get one thing, and I'm sure I'm missing something very basic, and am hoping that you can explain it here for me and perhaps others. 38V@4A = 152W. Even assuming 100% efficiency, how can an amplifier powered by this supply put out more than 152/2 = 76W per channel? Thanks in advance.

I'm no expert, but using Ohms Law in your calculation, we have 9.5ohms of resistance.
If the resistance is low as 4ohms, you get 9.5A of current and 361W of power...
But again, I'm no expert... Maybe @JohnYang1997 can clarify this.

 

[JPrufrk]

I'm no expert, but using Ohms Law in your calculation, we have 9.5ohms of resistance.
If the resistance is low as 4ohms, you get 9.5A of current and 361W of power...
But again, I'm no expert... Maybe @JohnYang1997 can clarify this.

I'm just using P=IV and conservation of energy. i.e., power in = 38V * 4A = 152W. So, 152 Joules/Second of energy in. How does one get more than that out? But, again, I'm probably missing something painfully obvious.

 

[Matias]

PS is DC, amp output is AC, so maybe there is the key.

 

[Sharpi31]

I’m surprised at some of the negative comments. The manufacturer is sharing real measurements (rare) and actively engaging with customer questions through this forum (even rarer). Of course design decisions have been made (I/O spec, external PSU, output power) and people are free to buy this or not depending on whether it meets their requirement. I just don’t understand some of the criticism and suggestions that Topping are being deceitful. I look forward to Amir‘s review, and hopefully he validates the measurements provided but Topping. I don’t need more than 50W and the form factor suits me, so I’m glad the product exists and that the manufacturer is sharing the information they have. Thanks @JohnYang1997 - I hope this is a successful product for you.

 

[JPrufrk]

PS is DC, amp output is AC, so maybe there is the key.

I don't think so, unless the power numbers quoted are peak powers, which would be pretty questionable IMHO. Maybe that is indeed the case. To @Sharpi31 's comment, I'm not criticizing the amp itself or Topping and I also appreciate the information that Topping provides; Topping and @JohnYang1997 have proven to be pretty straightforward here, so I suspect the numbers given are accurate, but they just don't make sense to me and I'd like to understand (as I'm sure would others) how they're derived.

 

[pjug]

@JohnYang1997
Is it OK for a customer to use a different power supply? Is there a performance gain (dynamic power at 6ohms or 4 ohms) using something like this?

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[Trokox]

I’m surprised at some of the negative comments. The manufacturer is sharing real measurements (rare) and actively engaging with customer questions through this forum (even rarer). Of course design decisions have been made (I/O spec, external PSU, output power) and people are free to buy this or not depending on whether it meets their requirement. I just don’t understand some of the criticism and suggestions that Topping are being deceitful. I look forward to Amir‘s review, and hopefully he validates the measurements provided but Topping. I don’t need more than 50W and the form factor suits me, so I’m glad the product exists and that the manufacturer is sharing the information they have. Thanks @JohnYang1997 - I hope this is a successful product for you.

I agree with you in every written word! This little amp ($ 350) measures better than most amps that cost over $ 1000 and $ 2000 and has enough power to please almost all audiophiles and some members here are just trying to criticize and see the seams, they really don't. I understand why this attitude, this is probably the most important community of audiophiles on the web and I think there should be more respect and support for the work of others.

 

[ModDIY]

Exactly, we are not critical of Topping's work and I appreciate the responsiveness of the manufacturer.

In addition, it is normal to ask questions or raise points that seem important to us. It can only be good for understanding and appreciating the design of a product.

Here we have a very powerful desktop amplifier that looks very well designed, well done again to Topping.

I convinced my friend to buy the Topping PA3S, I wouldn't have done it if Amirm hadn't measured it.

So I repeat, my goal is not to get this product off but rather to understand.

Thanks again.

 

[pma]

This is my engineering/technical opinion:

1) Topping makes excellent DACs, probably best in the world
2) Topping makes very good preamps, however at expense of some idiosyncrasies like <2kohm input impedance so the universality is restricted
3) Topping makes not very good to mediocre power amplifiers, for some reason, like not appropriate design skills in this specific field

 

[Sharpi31]

3) Topping makes not very good to mediocre power amplifiers, for some reason, like not appropriate design skills in this specific field

Do you mean before the PA5, or including the PA5?

 

[pma]

Do you mean before the PA5, or including the PA5?

Both. And I have already explained in this thread what I do not like with PA5. Easy to find it.