Pop noise often occurs when turning on,off class d amps

[gasolin75]

What's more annoying than turning on,off you hifi amp (mostly class d) and it makes some pop noise (some more than others), as you can see in the thumbnails,
many do it but some don't or very little, like a wiim amp ultra and topping mini 300 (very weak when i turn it off)

Why do they do it, even when an amp like a topping mini 300 that is surpose to be one of the best, it still do it when i turn it off (like 99.5 % pop noise free, don't know what to call it other than pop noise)

AIYIMA A20

FOSI AUDIO V3

3e Audio A5


Topping Mini 300

 

[fpitas]

I have heard no pop or other noises from my Mini 300. Do you have extremely sensitive speakers?

 

[gasolin75]

It just sometimes very very faint when i turn it off

 

[fpitas]

It just sometimes very very faint when i turn it off

I'll listen closely next time. So far though, I haven't noticed anything of the sort. My Mini is hooked directly to a horn driver, so that's kind of a worst case.

Is it possible something ahead of the amp is introducing a pop?

 

[amper42]

No Pop on or off with Boxem Purifi Arthur 4215/E2

 

[somebodyelse]

I don't know where you get 'mostly class d' from. I get more from an old class AB Rotel integrated or a Quad 520f than from Hypex UcD180 or UcD32MP based amps. I don't remember about the SMSL SA90 which probably means it's not as bad as the Rotel.

 

[stuartkohl]

I haven't noticed a problem with turn-on/turn-off transients when using the Topping Mini 300. My speakers are high in sensitivity, so any problems in this area would be exaggerated over less sensitive speakers.

A Buckeye NCx252MP amplifier doesn't have this problem in my system either.

Edited: As others have pointed out, my experience has to do with the implementation and not Class D itself. I was just trying to offer rebuttal to the idea that all Class D amps on the market exhibit "popping."

 

[Redacted]

Nothing to do with class-D per se - it's a design feature to mute or not bother to mute at startup.
I can't hear my Hypex at startup through the speakers (or when changing sources), but I can hear relays in the amp click at power-up.

 

[mcdn]

Nothing to do with class-D per se - it's a design feature to mute or not bother to mute at startup.
I can't hear my Hypex at startup through the speakers (or when changing sources), but I can hear relays in the amp click at power-up.

Yep, all the relevant amp chips/modules (TI, Hypex, ICEpower, etc) have controlled startup and shutdown processes, but not every implementation uses them. Also some amps might have a bit of DC offset inherent to the power supply, so there's that too. Either way, totally down to the implementation, nothing to do with Class D.

 

[MaxwellsEq]

I had a Class AB amplifier for 20+ years. It had relays with a delay on the output which resulted in almost no switch-on thump. But turning off resulted in quite a clunk.

I now have a Purifi 1ET400A Class D amplifier which is silent on switch on and off.

 

[Sokel]

Four pieces of icepoewer, 2x1200as2, 2x300a2, if they ever audibly popped they would be out of the window.
Imagine doing it every time they go into standby or off.

I CAN do them pop if I want, but upstream as a system, hook up something with a little bit of DC for example who would mess up anything downstream.
Or choose the wrong grounding scheme, or or...

A DMM is the best friend of gear, DC is the enemy.
Whenever I detect something other than zero DC (single digit at most, at amps mainly) , this piece of gear becomes readily salvageable for DIY parts (if quality parts inside) .

 

[Roland68]

What's more annoying than turning on,off you hifi amp (mostly class d) and it makes some pop noise (some more than others), as you can see in the thumbnails,
many do it but some don't or very little, like a wiim amp ultra and topping mini 300 (very weak when i turn it off)

Why do they do it, even when an amp like a topping mini 300 that is surpose to be one of the best, it still do it when i turn it off (like 99.5 % pop noise free, don't know what to call it other than pop noise)

AIYIMA A20
View attachment 553124
FOSI AUDIO V3
View attachment 553125
3e Audio A5
View attachment 553126

Topping Mini 300
View attachment 553128

These popping sounds often don't originate in the device itself, but rather in the equipment connected upstream. This is also the reason why it occurs with the same device for some users/systems and not for others.

Please measure the signal at both the input and output of the amplifiers to ensure that the popping sound wasn't already present at the input and subsequently amplified.

 

[fpitas]

I tried many ON/OFF cycles on my Mini 300. Once, by turning OFF then ON quickly I heard the tiniest pop from the horn. The horn has 111dB/W sensitivity, so that's still not much pop power.

 

[Golfx]

No pop from my hypex or purifi.

 

[Oeilvert]

I've tried a few TPA3255 amps... Single rail front end such as Fosi V3 which pop, split rail front end such as Ampapa D1 with no pop... It's to do with the circuit stabilizing as the inrush fills the capacitors, I once repaired a Meridian class A/B dual mono amplifier which loudly popped at power on but only on one channel - The power on delay circuit timing cap had dried up in that channel, replaced that and it was silent again.

Now using Icepower, no power on pops & much cooler running, happy days.

 

[ziggurcat]

I have heard no pop or other noises from my Mini 300. Do you have extremely sensitive speakers?

Mine has had a pop since the day I first turned it on. When powering on, there's about a 2-3 second delay, and a very faint tick (if I play any music before the tick occurs, no sound comes out of the amp). When I power the amp down, there's a very audible pop that is much louder than the power on tick. This will happen even when there's nothing else connected to the amplifier (i.e. only speakers, no other devices).

The power off pop is audible from 7 feet away, even. The power on tick is not at that distance.

Edit: I took a video -- link is here:

IMG_4952.MOV

drive.google.com

Let me know if there's any issues accessing the video (I should have set it so anyone with the link can view). You'll hear a couple of remote clicks because Topping just added a feature on the DX5 II to set the 12v trigger to sync with lineout instead of power, so that's just me cycling to the LO BAL output. You might hear a second remote click when I cycle back to the HPA output on the DX5 II, which immediately turns the amp off with this new feature (I would turn the volume up to hear it properly).

These popping sounds often don't originate in the device itself, but rather in the equipment connected upstream. This is also the reason why it occurs with the same device for some users/systems and not for others.

Please measure the signal at both the input and output of the amplifiers to ensure that the popping sound wasn't already present at the input and subsequently amplified.

What does it mean if there's a very noticeable pop when powering off the amp if there is nothing connected to the amp other than a pair of speakers? Is there a way to mitigate this?

 

[dualazmak]

Even though I do not use Class-D amp at all, to protect my treasure SP drivers, I always perform my routine careful "start-up/ignition sequences" and "shutdown sequences".

If you would be interested in such sequences, please visit the bottom portion of my rather lengthy post #931 on my project thread.

 

[gasolin75]

The thread was meant to help others in need of a new low power consumption class d amp, to avoid something with pop sound turning it on/off

I just hate that

 

[RexrothPigeon]

The thread was meant to help others in need of a new low power consumption class d amp, to avoid something with pop sound turning it on/off

and we're learning that (A) the title's ascribing that pop to class D is inaccurate and (B) the pop can be caused by the amp in some cases but also by other factors in the signal chain

(fwiw i also hate that and I'm glad none of my equipment does it)

 

[anonyless]

my A5 (newer version with the option to disable auto power off) doesn't have any power off pop, neither does my PAM152 . but the WiiM Vibelink on the other hand - very noticeable pop. all amps were connected to the same speakers. my assumption? WiiM do not bother to implement delay relay to prevent the power off/on pop, while 3e Audio does.