Topping PA5 Review (Amplifier)

[Eldus]

I just tested my PA5 for you, paying extra close attention, and it does make a very quiet 'tick' in my speakers when I turn it on, and slightly more noticeable 'tick' when I turn it off using the front switch. I don't really hear this in normal operation though. My PA5 is also not truly 100% silent, but I can't hear anything unless I put my ear POINT BLANK against the tweeter of my Revel M105's, and then I can hear the faintest of noise.

To exaggerate the noises I just explained, I put my iPhone 12 Pro's microphone in direct contact with the tweeter grill on one of the Revel M105's and recorded the power on followed by power off 5 seconds later, and you can hear all of it since the mic is just a few mm from the tweeter.

I uploaded the audio to SoundCloud. Here is an explanation (mic point blank on tweeter the whole time):

• tick at 2s is the physical sound from 1M away of me flipping the PA5 power switch (a good reference for loudness)
• a quieter tick at 5s is from the tweeter after the PA5 is powered on
• there is a tiny increase in noise from the tweeter that can be heard from that point until 10s
• a final tick at 10s is from the tweeter when the power switch on the PA5 is turned off

https://soundcloud.com/dan-cunningham-764711364%2Fpa5-speaker-tick

Are you using a balanced DAC?

 

[anotherhobby]

Are you using a balanced DAC?

I'm feeding it from a balanced miniDSP Flex. Behavior is identical if I unplug the input cables from the PA5, or if I switch the PA5 to use the other input that is not in use.

 

[simplywyn]

I had to return my PA5 due to crackling noise from one channel after leaving it on for an hour - whenever i leave it on, it starts to crackle. Anyone else have this problem?

For me I'm having a noise problem, as if it is a crackling noise issue. Returning this amp.

 

[simplywyn]

OMG looks like the past 4-5 posts haev this problem

 

[pjug]

• there is a tiny increase in noise from the tweeter that can be heard from that point until 10s

https://soundcloud.com/dan-cunningham-764711364%2Fpa5-speaker-tick

I can't imagine this amp should hiss at all with 86dB speakers, even with your ear right on the tweeter. Do you get hiss if you short the inputs?

 

[simplywyn]

I get a hiss even if the inputs a disconnected

 

[pjug]

I get a hiss even if the inputs a disconnected

I don't know if it will matter but I wonder if you get it with inputs shorted. I only get slight hiss with my ear to the tweeter on 87dB speakers with Outlaw M2200, and the noise of the PA5 is 20 dB lower than the Outlaw.

Maybe I misunderstand. Does the hiss go away after 10 seconds or does it persist?

 

[anotherhobby]

I can't imagine this amp should hiss at all with 86dB speakers, even with your ear right on the tweeter. Do you get hiss if you short the inputs?

That "hiss" is imperceptible. Seriously, it's totally inaudible. I thought this amp was 100% silent the first time I put my ear up close to one of my speakers. I've never heard it until until my ear was up against the tweeter and I flipped the power to see if I could hear something. The interruption made me notice the "hiss" sound. I was just performing a test for a fellow forum member. I've literally never heard it before, and I can't hear it now unless I put my ear so it is physically touching the tweeter grill, and then I can barely hear it. It's magnified by the phone microphone, which is just mm's from the tweeter.

But yeah, it's not DEAD silent. ¯\_(ツ)_/¯

 

[anotherhobby]

I had to return my PA5 due to crackling noise from one channel after leaving it on for an hour - whenever i leave it on, it starts to crackle. Anyone else have this problem?

For me I'm having a noise problem, as if it is a crackling noise issue. Returning this amp.

This should not happen. I sit 1M from my speakers powered by my PA5 for 8+ hours a day working from home. It's either Music, a zoom meeting, or silence. The amp is always on, and I've never heard a single odd artifact. It honestly sounds flawless to me, and I couldn't be happier. If yours is legit "crackling" then you have a problem.

 

[IPunchCholla]

I would agree that crackling or a thump are indications of something wrong. I have no sound in the tweeter with the input connected and amp on with no music playing. Nothing. It is dead silent.

I get no sound when turning the amp switch off is no amplified source is going to it at the time (my PA5 is fed by my L30). I get a very slight thump in both speakers if the power of the amp is turned off (using the switch) while receiving an amplified source (even if nothing is playing). I get a slightly louder thump if power is cut externally to the amp while an amplified source is connected.

 

[Toku]

I use my PA5 just for my tweeters in an active XO so amps are all on a triggered power strip. If I kill power to the system I get some scratchy grunge coming through the tweeters but nothing if I use the switch on the front of the PA5. I just turn off the PA5 first before powering everything else down and then flip the switch back up so it's ready to go next time. Not ideal, but not a deal breaker for me as the amp stack is close at hand.

The symptoms are common to all PA5s. The only disappointing point of PA5.
I tested PA5 shortly after launch and posted this issue on the forums.

Topping PA5 Review (Amplifier)

It is going to be fine. In the extreme you may need to ground its input as stated but I would not worry about it. Thanks! One question left though. Using an RCA splitter adapter (attached below) for my AV receiver's center channel preout and using both channels of PA5 to bi-amp my center...

www.audiosciencereview.com

 

[Toku]

I'm feeding it from a balanced miniDSP Flex. Behavior is identical if I unplug the input cables from the PA5, or if I switch the PA5 to use the other input that is not in use.

If the noise appears even when nothing is connected to the input of PA5, it is a malfunction of PA5.

 

[wlgreg]

I had to return my PA5 due to crackling noise from one channel after leaving it on for an hour - whenever i leave it on, it starts to crackle. Anyone else have this problem?

For me I'm having a noise problem, as if it is a crackling noise issue. Returning this amp.

I had the exact same problem. Returned to APOS, replacement unit is on the way. Hopefully the replacement won't have the same issue.

 

[simplywyn]

I had the exact same problem. Returned to APOS, replacement unit is on the way. Hopefully the replacement won't have the same issue.

Ok returned to Amazon, ordered another one in the meantime...

 

[AudioArchitech]

PecanPi cranked to max volume, PA5 cranked to max volume, dead silent ear against the tweeter. I can hear a very very faint pop when I turn PA5 off, it's really not bothersome at all, barely notice it. When the PecanPi's volume is dialed down to where I normally keep it, no click sound at all when I turn off PA5. (I was getting more noise when running Unbalanced with E30 DAC)

 

[llmm0o]

SINAD score

In my opinion, scoring amplifiers of class-d by crosstalk is better.

 

[simplywyn]

PecanPi cranked to max volume, PA5 cranked to max volume, dead silent ear against the tweeter. I can hear a very very faint pop when I turn PA5 off, it's really not bothersome at all, barely notice it. When the PecanPi's volume is dialed down to where I normally keep it, no click sound at all when I turn off PA5. (I was getting more noise when running Unbalanced with E30 DAC)

The crackling sound is regardless of volume.

 

[AudioArchitech]

The crackling sound is regardless of volume.

I was just giving feedback, not having that issue here.

 

[antcollinet]

I get a hiss even if the inputs a disconnected

You have to short the inputs to eliminate interference pickup. They are designed to be driven from low impedance. Open circuit isn't.

 

[mikolaj]

After ~2 months my amplifier has broken.
It constantly sends hissing sounds and cracks to the left channel regardless of being connected to any input and amplifier power level.
Anyone experienced something like that?