Topping PA5 Review (Amplifier)

[pkane]

Is the phase plot correct? FR is flat up to 10kHz and there is a -50° phase at 10kHz? -16° at 1kHz? Isn't there some delay (in the meas. setup)?

Turns out the delay wasn't removed quite right. I adjusted it manually to get this:

 

[spacevector]

Turns out the delay wasn't removed quite right. I adjusted it manually to get this:
View attachment 175644

A phase lead? Doesn't look right.

 

[pkane]

A phase lead? Doesn't look right.

What do you mean by "phase lead"? This is straight out of REW, all I did was adjust the time offset to remove constant slope.

 

[pkane]

THD+N over frequency sweep (5W, 8Ohms):

IMD SMPTE 60Hz/7kHz 4:1

CCIF 19kHz/20kHz 1:1

Multitone

 

[spacevector]

What do you mean by "phase lead"? This is straight out of REW, all I did was adjust the time offset to remove constant slope.

Most other phase responses I have seen show the phase angle is negative for higher frequency, meaning the output of the amplifier lags the input signal. This is commensurate with a low pass filter response.

Could just be a convention thing.

 

[Crosstalk]

your dream come true
One of the best speakers in the world.
I just don't know if the B&W 800 didn't have ferrofluid in the tweeters. How does it work after all these years? Because I heard that ferrofluid can dry up.

Without ferrofluid it’s would still work. But not with the same response depends on if the response depends on the fluid per design

 

[0bs3rv3r]

Do I understand correctly, that beacause of the input sensitivity of 2.5 Volts, everything above an input of 2.5 Volts, will clip the signal?
If so, how can I be sure I limit my DAC to an output of 2.5 V?

You could find out, or measure, what the maximum output of your DAC is, and use simple resistive voltage dividers on each output to bring that down to 2.5V.

 

[pkane]

Most other phase responses I have seen show the phase angle is negative for higher frequency, meaning the output of the amplifier lags the input signal. This is commensurate with a low pass filter response.

Could just be a convention thing.

That's just inverted polarity. I can flip it in REW by pushing a button.

 

[bsas]

Unfortunately your experience seems to contradict others I have read, and that's exactly why I ASR doesn't like subjective reports. It's weird how this thread seems to be asking for them now.

Well, I never said the amp wasn’t good. With the more efficient JBLs and sitting closer it sounds amazing.

My only observation was “it is underpowered FOR ME”. This is not subjective, it’s a fact, but also it’s not an universal truth… (and I never said it was)

 

[JeffGB]

Do I understand correctly, that beacause of the input sensitivity of 2.5 Volts, everything above an input of 2.5 Volts, will clip the signal?
If so, how can I be sure I limit my DAC to an output of 2.5 V?

This isn't really a thing because when your DAC hits 2.5v the amplifier is going to be wide open. If you simply don't turn it up to distortion, it will be fine, just like any other amplifier.

 

[MarkWinston]

Well, I never said the amp wasn’t good. With the more efficient JBLs and sitting closer it sounds amazing.

My only observation was “it is underpowered FOR ME”. This is not subjective, it’s a fact, but also it’s not an universal truth… (and I never said it was)

It is underpowered for you but the A07 has enough?

 

[bsas]

It is underpowered for you but the A07 has enough?

No, the A07 is a little underpowered for me too, but less than the PA5 and with a more defined bass… (don’t know why since the PA5 was supposed to be 65W at 8 ohms and the A07 is supposed to be 65W too).

To be honest I am testing a preamp before it and it helps a lot, but, I am probably crossing the 2Vrms threshold, so, very likely going into distortion.

 

[Yaiba]

No, the A07 is a little underpowered for me too, but less than the PA5 and with a more defined bass… (don’t know why since the PA5 was supposed to be 65W at 8 ohms and the A07 is supposed to be 65W too).

To be honest I am testing a preamp before it and it helps a lot, but, I am probably crossing the 2Vrms threshold, so, very likely going into distortion.

Are you use unbalanced connection to PA5 ?

 

[mario_rouge]

according with Amir's measurements the Topping pa5 has 48watt 8 ohm

 

[antcollinet]

according with Amir's measurements the Topping pa5 has 48watt 8 ohm

About 85 at 1%THD though which is how the A07 is rated.

 

[antcollinet]

No, the A07 is a little underpowered for me too, but less than the PA5 and with a more defined bass… (don’t know why since the PA5 was supposed to be 65W at 8 ohms and the A07 is supposed to be 65W too).

To be honest I am testing a preamp before it and it helps a lot, but, I am probably crossing the 2Vrms threshold, so, very likely going into distortion.

So if you are not giving the amp enough volts, (presumably from an unbalanced connection) you can't say it is underpowered - only that you are not driving it properly.

 

[pma]

THD+N over frequency sweep:

What is the power and load? BTW, stepped sine method has better distortion resolution (lower noise floor) than the frequency sweep. But it seems you used the stepped sine.

 

[UAN]

Guys, measure the DC voltage at the PA5 outputs.
I have about 30 mV.

 

[MarkWinston]

No, the A07 is a little underpowered for me too, but less than the PA5 and with a more defined bass… (don’t know why since the PA5 was supposed to be 65W at 8 ohms and the A07 is supposed to be 65W too).

To be honest I am testing a preamp before it and it helps a lot, but, I am probably crossing the 2Vrms threshold, so, very likely going into distortion.

Purifi sounds better? Yeah, probably. Hypex outperforms it? Possible. A07 sounds better? Check what is wrong with your PA5 because that is not even possible. And I own the A07 with several PSUs. Not even close.

 

[antcollinet]

Guys, measure the DC voltage at the PA5 outputs.
I have about 30 mV.

About 0.1mW into 8Ω / 0.2mW into 4Ω

Is that a problem? I've no idea what is typical for an audio amp.


EDIT: My pioneer AVR is measuring 37mV DC with no input.