Topping PA5 Review (Amplifier)

[KSTR]

I guess it is related to the bandwidth limiting in the AP-filter.

No, as this was a THD+N vs Power plot, not vs Frequency

 

[anphex]

Ordered and paid 3rd December 2021, still no shipping or any message

 

[maty]

BAD IDEA with Topping PA5 if you need watts. With RCA only 2 V -> much less power with PA5.

I do not remember the result of the calculation of the volts necessary to reach the maximum power with PA5. Near 3 V I think but I am not secure ¿2.8 V?

 

[Mulder]

No, as this was a THD+N vs Power plot, not vs Frequency

OK Right

 

[maty]

A note as to the phase. In traditional amplifiers (class A, AB ...) the phase has never been a problem, since it was almost flat up to 20 kHz, that is why it is hardly ever specified.

Only Purifi and Orchard Audio (Starkrimson amp) know that the phase barely drops a few degrees at 20 kHz. Of the rest of class D amps, I doubt it a lot -> bad idea with tweeter ir you listen to good acoustic / electric recordings. With modern recordings, without physical instruments, no problema.

Amir is reluctant to measure the phase. If he did, we would get rid of doubts with the class D amplifiers that he reviews.

 

[KSTR]

Amps are minimum phase, so phase directly follows from frequency response.
If you want to know the approximate phase error at 20kHz (not that it matters, though), model the FR in a circuit simulator and look at the phase.

 

[Lambda]

BAD IDEA with Topping PA5 if you need watts. With RCA only 2 V -> much less power with PA5.

You need exactly the same voltage with RCA as with XLR...
there is no Rule that says RCA can only be 2V
Input sensitively is 2.6V so even if your output is only 2V you loose only ~2dB.

A note as to the phase. In traditional amplifiers (class A, AB ...) the phase has never been a problem, since it was almost flat up to 20 kHz, that is why it is hardly ever specified.

Only Purifi and Orchard Audio (Starkrimson amp) know that the phase barely drops a few degrees at 20 kHz. Of the rest of class D amps, I doubt it a lot -> bad idea with tweeter ir you listen to good acoustic / electric recordings. With modern recordings, without physical instruments, no problema.

Amir is reluctant to measure the phase. If he did, we would get rid of doubts with the class D amplifiers that he reviews.

As long as the Phases error is constant and steady this is no problem.
But if it is not smooth and and steady. or worse inter modulated it can become audible
As research showed some humans can reliably hear 4µs of shift.
I would not be supervised if some golden ears can subconsciously notice 1µs.

Current trough the Output inductors change there inductance and thereby also modulates the phases.
How mush? we don't have the data to tell.
Maybe its not relevant but it it would be nice to systematically test this and measure inductor/filter linearity and inter modulation.

 

[Eggs Ackley]

Ordered and paid 3rd December 2021, still no shipping or any message

Ordered and paid Nov. 26. FedEx label created Dec. 4. Package yet to be handed to FedEx. During these times delays are the norm. Oh well.

 

[Matias]

Amps are minimum phase, so phase directly follows from frequency response.
If you want to know the approximate phase error at 20kHz (not that it matters, though), model the FR in a circuit simulator and look at the phase.

@KSTR you seem to be very knowledgeable of audio circuits in general, I read you worked for ADAM before. Could you tell us where do you currently work? Thanks!

 

[anphex]

I wouldn't be so nit picky if they didn't charge the 340 € right away instead of when it actually went out for shipping -_-

 

[KSTR]

@KSTR you seem to be very knowledgeable of audio circuits in general, I read you worked for ADAM before. Could you tell us where do you currently work? Thanks!

I switched sides, developing musical synthesizers/keyboards. All digital stuff (complex computer systems, actually), only little analog audio circuits involved but of course lots of ancillary analog/linear circuits of all kinds, and lots of programming (my educational background is computer engineering, besides classic EE).
Audio is a hobby now (apart from occasional consulting/measurement tasks and custom contract design work).

 

[anphex]

I switched sides, developing musical synthesizers/keyboards. All digital stuff (complex computer systems, actually), only little analog audio circuits involved but of course lots of ancillary analog/linear circuits of all kinds, and lots of programming (my educational background is computer engineering, besides classic EE).
Audio is a hobby now (apart from occasional consulting/measurement tasks and custom contract design work).

If I had to wildly guess looking at your location and history I bet it's Native Instruments.

 

[KSTR]

@anphex,
close, but no cigar ;-)

 

[Moosi]

Are there steps in the volume knob? Does it have reassuring slight humps/bumps when turned or is it loose? And how hard is it to turn? Like a game of Roulette or like a rusty iron nut on a frozen water pipe?

 

[maty]

You need exactly the same voltage with RCA as with XLR...
there is no Rule that says RCA can only be 2V
Input sensitively is 2.6V so even if your output is only 2V you loose only ~2dB.

Usually, RCA outputs from DAC: 2V. XLR: 4V or more.

 

[maty]

Pro-Audio and Lighting Calculators : dBs, time, arrays, Hz, DMX ...

Calculators: sound reinforcement (SPL, voltis, dBm, cable, coverage, wavelength, frequency, time, distance, arrays), lighting (DMX) and projection

www.doctorproaudio.com

Loudspeaker: 85 dB, 4 Ohms. I want 80 dBSPL continuous +15 dBSPL peak at 3m. Random phase.

If 80 watts -> 97.5 dBSPL (Topping PA5, 2.6V)

Then 50 watts -> 95.5 dBSPL (Topping PA5, 2V)

 

[maty]

Amps are minimum phase, so phase directly follows from frequency response.
If you want to know the approximate phase error at 20kHz (not that it matters, though), model the FR in a circuit simulator and look at the phase.

I say that it would not cost as much for Amir to measure the phase of these small class D, at least once for each chip used. And so there would be no doubt.

 

[Lambda]

80 watts -> 97.5 dBSPL (Topping PA5, 2.6V)
50 watts -> 95.5 dBSPL (Topping PA5, 2V)

97.5-95.5 = 2dB as i said

you loose only ~2dB.

 

[bravomail]

And you seem to believe that the captured music has the same "phase accuracy" in microphone paths. Do you have an idea how their response looks like? And have you ever analyzed the "768kHz data files" for their spectral content? So where does it end?

search utub for "binaural". they use special dual microphone setup with "human-like" ears. it works. u-tub usess 88kBit AAC - but it still works!

 

[Toku]

Ordered and paid 3rd December 2021, still no shipping or any message

I ordered on November 23rd and arrived on December 8th. It was delivered by FeDex, but is currently delayed considerably due to the aftereffects of a large bargain sale in China. It takes nearly twice as many days as usual.