Topping PA5 Review (Amplifier)

[pkane]

Just tested, both signals on each XLR generates 2.065V (expected) and obviously 4.13V if you compare them to each other using a 1kHz sine wave input.

The TRS to RCA cable is also outputting perfect 2.065V on the same wave.

I tested again with a louder white noise source and still, on the same output level on the E50 DAC the Aiyima consistently produces 10-12db louder output.

10dB louder at the same input level should be exactly per measured gain (19dB vs 29dB). If you want to make PA5 play louder, you'll need to feed it a higher level input. If your DAC can't produce it, then you'll need a preamp that can, or another DAC that can, or a different amp.

 

[BoredErica]

I don't understand. How can I make the PA5 louder? Providing MORE voltage on the input? If so, why the E50 (the recommended DAC from the manufacturer) doesn't provide the necessary voltage to it? And, if I provide more voltage on the input for BOTH, doesn't the A07 will still be louder?

I'm going to give my understanding of it, somebody can correct if wrong. Sometimes I think trying to explain something is a good way to iron out misunderstandings you or I might have.

Higher gain = everything plays at max volume with smaller voltage signal coming out of dac. Useful if dac can't output that much.
Lower gain = everything plays at max volume with higher voltage signal coming out of dac. Useful if you're noise-phobic and want the lowest possible noise floor. This is because noise you hear is dominated not by amp noise but rather the dac's, as the dac's noise is being magnified by the gain of the amplifier.

The input sensitivity of an amp tells you how high voltage signal you can give to the amp without the amp clipping. So yes, you could jack up the voltage to the AO7. You might get higher volume provided the amp is capable of delivering the output required AND the input of the amp does not clip. But if you crank it high up enough the pa5 takes over and wins.

If your dac cannot output enough voltage signal to the amp you can use a pre-amp instead to boost the signal.

An example is this Benchmark ahb2 spec sheet which has different gain settings. You can see here the max voltage the amp can take without clipping is lower as the gain increases.

Some dacs can push out a really high voltage signal, and by having to turn that down you're just losing performance.

 

[bsas]

Yes, AC voltage measured between tip and ring for TRS and measured between center pin and outer shield for RCA. Use a test tone, not white noise. I would try 1 kHz but depending on your multimeter you may need to use something lower in frequency like 100 Hz. Do this at a relatively low volume position (-30 dB). Then measure the voltage at the amplifier output (speaker terminals) at the same volume position. Basically we want to compare the voltage in and out of the amplifier.

Michael

Sorry, re-done measurements.

E50 set to -30: 0.065V each signal (so 0.13V on TRS, 0.065V on RCA)

A07 speaker outs: 2.72V
PA5 speaker outs: 1.174V

 

[bsas]

10dB louder at the same input level should be exactly per measured gain (19dB vs 29dB). If you want to make PA5 play louder, you'll need to feed it a higher level input. If your DAC can't produce it, then you'll need a preamp that can, or another DAC that can, or a different amp.

So, in summary, even if the PA5 is sold and advertised to go with the E50 DAC, it cannot produce enough volume (for my needs) unless I use a preamp?

Also, doesn’t that just proves what I kept saying that the A07 is louder than the PA5? Because, in theory, if I feed a hotter signal to the A07 (let’s say 3V) and the same signal to the PA5, the PA5 will still be 10db louder unless I hit a headroom ceiling on the A07, right?

 

[BoredErica]

Also, doesn’t that just proves what I kept saying that the A07 is louder than the PA5? Because, in theory, if I feed a hotter signal to the A07 (let’s say 3V) and the same signal to the PA5, the PA5 will still be 10db louder unless I hit a headroom ceiling on the A07, right?

As I mentioned earlier, the A07 will just clip and not get louder.

 

[bsas]

As I mentioned earlier, the A07 will just clip and not get louder.

OK, I got that. Obviously you cannot "assure" that unless I actually have a balanced preamp (which I don't) so I can see if the A07 actually clips or still have more headroom, right? (is there a way to know the clipping zone from those amps specs or Amir measurements?)

What really bothers me is the fact that the PA5 in theory, from the manufacturer specs, should be a "perfect match" for the E50. But, at least for my current speaker/room situation, the A07 is better

 

[pkane]

OK, I got that. Obviously you cannot "assure" that unless I actually have an balanced preamp (which I don't) so I can see if the A07 actually clips or still have more headroom, right?

What really bothers me is the fact that the PA5 in theory, from the manufacturer specs, should be a "perfect match" for the E50. But, at least for my current speaker/room situation, the A07 is better

Right. You'll need a higher level input into PA5 to get to satisfying levels with your speakers + room. A preamp, a different DAC, or more sensitive speakers could all help.

 

[BoredErica]

OK, I got that. Obviously you cannot "assure" that unless I actually have a balanced preamp (which I don't) so I can see if the A07 actually clips or still have more headroom, right? (is there a way to know the clipping zone from those amps specs or Amir measurements?)

What really bothers me is the fact that the PA5 in theory, from the manufacturer specs, should be a "perfect match" for the E50. But, at least for my current speaker/room situation, the A07 is better

My understanding is the "input sensitivity" spec is the voltage required for max power from the amp and beyond that is clipping. I don't know what the spec is for the A07. I can find the spec for ahb2 or pa5 though.

 

[bsas]

My understanding is the "input sensitivity" spec is the voltage required for max power from the amp and beyond that is clipping. I don't know what the spec is for the A07. I can find the spec for ahb2 or pa5 though.

Got it, thanks! I would love to know the input sensitivity of the PA5 vs the A07... Don't know where to look for it

 

[bsas]

Right. You'll need a higher level input into PA5 to get to satisfying levels with your speakers + room. A preamp, a different DAC, or more sensitive speakers could all help.

Got it, thanks! But at least I feel myself redeemed because when I said the A07 was louder a bunch of posts called me crazy... Now I know it IS louder if paired with the E50 DAC (which is literally the recommended DAC to go with the PA5)... oh well... maybe I will just need to find a reasonably priced balanced preamp

 

[DanielT]

If you just want to test, buy some super cheap little pre amp from China. I searched for Preamp ne5532 (ne5532 is the OP amp in the one that fixes the gain). They are built with some capacitors and resistors. Because of this, they should, purely theoretically, have low distortion and straight frequency response. Note should have.If that really is the case? I do not know.

Has anyone here tried such a small gadget? I think I order one for fun and try it myself.

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Edit:
I became so curious myself so I created a new thread where I ask about these:

Small cheap pre amp card/ boards , sound quality?

Has anyone tried any of these small cheap pre amp cards, with OP amp NE5532, from China? They hardly cost any money at all but are they ok? Attach some pictures of what it looks like (took some at random)...

audiosciencereview.com

 

[0bs3rv3r]

Got it, thanks! But at least I feel myself redeemed because when I said the A07 was louder a bunch of posts called me crazy... Now I know it IS louder if paired with the E50 DAC (which is literally the recommended DAC to go with the PA5)... oh well... maybe I will just need to find a reasonably priced balanced preamp

Needing a higher level input does not mean the PA5 is underpowered compared to the A07 though.

 

[africanus]

Topping E50 DAC has both balanced and single-ended outputs.
Topping PA5 has only balanced inputs.
Aiyima A07 has only single-ended inputs.

So, the intended use is:

E50 balanced output > PA5 balanced input
E50 single-ended output > A07 single-ended input

I am pretty sure this is the configuration used in measurements. Using the SE outputs on E50 to feed the PA5 with RCA-TRS adapters is a bit disconcerting to me.

 

[nhs]

I don't understand. How can I make the PA5 louder? Providing MORE voltage on the input? If so, why the E50 (the recommended DAC from the manufacturer) doesn't provide the necessary voltage to it?

You already reach the max rated power of the PA5 if you use the balanced output of the E50 at -3.7db.
As I correctly read:
PA5 input sensitivity = 2.6V
E50 bal. out = 4V

 

[MarkWinston]

I had no problems with 3 of my DACs, the SU9, SU9N and Sanskrit 10th MKII. I could drive the PA5 louder than my DA9 before it clips. In fact most of my speakers are running into distortion before anything happens to the amp.

 

[Lambda]

(using the balanced output of the E50 to a single ended cable: TRS to RCA cable)

That's a bad idea.

 

[mdsimon2]

Sorry, re-done measurements.

E50 set to -30: 0.065V each signal (so 0.13V on TRS, 0.065V on RCA)

A07 speaker outs: 2.72V
PA5 speaker outs: 1.174V

Nice, thanks for sharing. This tells us a lot of useful stuff.

First it says that you do not have any weird attenuation going on your Pi because if you scale up from the -30 dB volume you get the expected output voltage at 0 dB.

TRS: 0.13 x 10^(30/20) = 4.11 V
RCA: 0.065 x 10^(30/20) = 2.05 V

Next it says that the PA5 gain is exactly as we expected, 19 dB.

gain = 20 x log (1.174 / 0.13 ) = 19.1 dB

It also says that the A07 has even MORE gain than initially anticipated at 32 dB.

gain = 20 x log(2.72 / 0.065) = 32.4 dB

However the difference in gain would only suggest a 7-8 dB difference between the two, not the 10-12 dB difference you are seeing.
As mentioned a few times you should repeat the test using the RCA in to the A07, using a TRS to RCA adapter can certainly cause issues. The other thing that might be occurring is that the amps may have different frequency in to load so it is possible that even if they are similar at 1 kHz the A07 may have even more output at higher frequencies.

Either way at a given volume position it is clear that the A07 will always sound louder than the PA5.

Michael

 

[Draki]

Calculation voltage and power - gain and loss - sengpielaudio Sengpiel Berlin

Calculation: Voltage and Power - Gain and Loss - Eberhard Sengpiel sengpielaudio

www.sengpielaudio.com

 

[bsas]

Topping E50 DAC has both balanced and single-ended outputs.
Topping PA5 has only balanced inputs.
Aiyima A07 has only single-ended inputs.

So, the intended use is:

E50 balanced output > PA5 balanced input
E50 single-ended output > A07 single-ended input

I am pretty sure this is the configuration used in measurements. Using the SE outputs on E50 to feed the PA5 with RCA-TRS adapters is a bit disconcerting to me.

You misread. I am using a TRS cable to feed the PA5 as intended by the manufacturer.

I am using the TRS to RCA cable just to feed the Aiyima since it’s input is SE only and I wasn’t sure if the RCA output of the E50 was “hotter” so I wouldn’t compare different things.

 

[bsas]

I had no problems with 3 of my DACs, the SU9, SU9N and Sanskrit 10th MKII. I could drive the PA5 louder than my DA9 before it clips. In fact most of my speakers are running into distortion before anything happens to the amp.

So my PA5 is maybe defective? Can you measure yours? Simply feed a 1khz wave to it and measure voltage input and output to compare with my measurements please? Thanks!