WiiM Amp Ultra: Crackling of the speakers when turning on and off

[Stephan P.]

I recently purchased the WiiM Amp Ultra. So far, I'm very happy with it. The only thing that bothers me is the crackling of the speakers when turning them on and off. This shouldn't be happening; no other amplifier I've used has done this.
I've opened a ticket about this (#539967).
This should be preventable with a delay circuit. I don't know if it can be fixed with software.
Have you noticed this too?

 

[Valentino]

I haven’t noticed, but the Dynsudio Emit M10 bookshelf speakers I have connected to my Amp ultra are not very sensitive. What speakers do you use on yours?

Opening a ticket is the right thing to do.

 

[Stephan P.]

I connected Canton Plus F speakers to the amp. I had previously used them as Zone 2 speakers on a Yamaha RX-A2080 and, before that, on a previous model.

 

[Mr Ee]

Crackling? i.e. a reasonably prolonged sound?
Or a quiet pop sound whose volume is unrelated to the amp's volume setting?

 

[Stephan P.]

A rather quiet cracking noise whose volume is unrelated to the amp's volume setting.

 

[Wiimer]

A rather quiet cracking noise whose volume is unrelated to the amp's volume setting.

The one-time sounding spike noise is not specific to your device. Mine is the same. If it sounds continuously, there could be a problem with your device (or system).

 

[Stephan P.]

Thanks, it's good to know it's not a defect. It would still be nice if this annoying noise could be avoided.

 

[Wiimer]

Thanks, it's good to know it's not a defect. It would still be nice if this annoying noise could be avoided.

This is probably difficult to fix as I hear the same sound on the Amp Pro and Vibelink amp. Many of my Class D amps have a spike noise when powered on/off.

 

[slartibartfast]

This is probably difficult to fix as I hear the same sound on the Amp Pro and Vibelink amp. Many of my Class D amps have a spike noise when powered on/off.

With the WiiM Amp I hear a few noises from the sub during power up but not through the main speakers.

 

[Valentino]

Is it not a continuous noise but a faint pop/burst on power up/down?
That’s not a problem.

 

[Wiimer]

With the WiiM Amp I hear a few noises from the sub during power up but not through the main speakers.

Yes, there is no spike in the WiiM amp. Probably related to PFFB, but I don't know the details.

 

[hgb]

Hi,
Experiencing the same pop/burst on power up with my Amp Pro. Prior Bluesound Powernode never did that.
Somehow unrelated to volume setting but barely noticeable when amp stage powers up at 0 volume so maybe fixable by introducing a short delay.
Created a ticket in case

 

[chardo]

Hi, i'm having the same problem with my Wiim Ultra and my Teufel Stereo M2 speakers.
But, I should point out, it doesn't happen all the time, but it does happen regularly.

 

[anonyless]

Thanks, it's good to know it's not a defect. It would still be nice if this annoying noise could be avoided.

if by crackling you mean a low pop sound in the speakers (regardless of amp volume like you mention) when amp goes into standby or turn off - then yes, it's a common thing, my Vibelink has the same issue.
and YES, it is an issue. many people are normalizing this issue and refer to it as being "normal", but that won't make it go away.
other amp manufacturers (with the exact chip) found a way to prevent this pop sound from acouring (like 3e Audio)

 

[Wiimer]

Hi, i'm having the same problem with my Wiim Ultra and my Teufel Stereo M2 speakers.
But, I should point out, it doesn't happen all the time, but it does happen regularly.

That might be a different issue from the Amp.

Do you hear pop noise from the speakers when switching Ultra's standby on/off?

 

[chardo]

That might be a different issue from the Amp.

Do you hear pop noise from the speakers when switching Ultra's standby on/off?

Yes

 

[harkpabst]

and YES, it is an issue. many people are normalizing this issue and refer to it as being "normal", but that won't make it go away.
other amp manufacturers (with the exact chip) found a way to prevent this pop sound from acouring (like 3e Audio)

It's normal for the WiiM devices, it's no indication of a faulty device. This is the important point here.

If you cannot live with this, you have to move on to a different product.

 

[hgb]

Might be "normal" for WiiM devices but still agree it is an issue as I read this behavior has been improved via firmware on similar Class-D network amplifiers from other brands, so it seems technically achievable.
Possible firmware-only mitigations (no hardware change) to be considered:

• enforce mute before power-down and after power-up stabilization
• add a short gain ramp (fade-in / fade-out) around standby transitions (50–300 ms)
• slightly extend the soft-mute timing during standby entry/exit

Conscious it is probably complex (otherwise WiiM would have done it from start) but might worth digging? Will do my best to follow-up with the support service in case they can do something cause would be a material improvement

 

[Wiimer]

Yes

Could your active speakers be producing pop noise? I've never heard pop noise when turning the Ultra on / off.

 

[anonyless]

It's normal for the WiiM devices, it's no indication of a faulty device. This is the important point here.

If you cannot live with this, you have to move on to a different product.

where did i write that it's a "faulty device" ? it's an issue. a bug. a bad design. call it what you will.
the fact the newest amp from the WiiM amp line still have this issue (IF we're talking about the same low pop sound issue) same as the Vibelink - that's just sad