UMC-200 and Thumping or Popping through Sub

[viablex1]

Hello all

I just picked up one of these units and was wondering did Emotiva ever get this fixed? or is there a way for me to configure my gear so this won't happen?

Whenever I change from one input to another or when I am changing the mode from direct to stereo the pop or thump happens through the sub. I have changed lfe cords etc.

Any ideas?

I am waiting to hear back from tech support I think they are at lunch they are an hour behind me, so I will post my results

thanks

Matto

[vcautokid]

What is volume set at. Or is it at lowest setting? Do you still hear it?

[viablex1]

Hey thanks for the reply, I have it set to normal listening levels usually for instance I  have it on between 35 and 40 and then change the mode , or just when turning the unit on no sound is coming out but I need to change to coaxial input, or even when watching a program and pausing it then retarting it I get the pop. I am not sure if I answered your question meaning if you mean the sub it is set to about hallway.

Thanks

matto

[viablex1]

but when I get home tonight I will try the volume on the lowest setting and see what happens and report back.

everything else seems great with it, really good sound

Matto

[ansat]

Jan 9, 2015 14:55:57 GMT -5 viablex1 said:

but when I get home tonight I will try the volume on the lowest setting and see what happens and report back.

everything else seems great with it, really good sound

Matto

It sounds like this is the subwoofer coming out of sleep mode. With the LFE cable disconnected, power down the sub and power it back on. Do you get the same noise?


Tony

[viablex1]

will try it and let you know

Thanks

Matto

[viablex1]

okay sub is on and not in sleep mode, I powered it down and back on still the same thing. I have the latest firmware.

Also and I don't know if this is important, per se. It is when you have audio from the oppo and it is playing, if you switch to another input it pops , if you FF the movie that is playing , it pops, on some special features the audio codec is different it pops and will identify the new codec.

The pop is only through the sub and not the rest of the speakers.

Other than this man the sound is really good, especially on I robot holy moly!!!

I haven't heard from tech support as of yet but my friend who has been in the business since dinosaurs walked the earth says just chill they will get back to me, and I don't really have any reason to believe they won't I will probably wait unitl next Tues. when I am off work.

so will f/u then

Matto

[viablex1]

I called support Friday but I think they were busy, I will call tomorrow in the morning,

If there is no component with audio on it won't pop , once you turn something on an start switching inputs or press mute the popping starts, the only thing I haven't tried is an Xlr cord but the sub doesn't have that as an option, I have heard in the past that that works. I have tried switching hdmi using optical, actually with optical from the TV is the worst culprit pausing etc

Matto

[Gary Cook]

I only get the slightest thump, and not that often, when the cable box is the source. The Apple TV3 doesn't do it, the Oppo 103 doesn't do it, the ERC-3 CD player doesn't do it, the inbuilt radio doesn't do it, the Panasonic BD player doesn't do it and the blue tooth model BTM-1 doesn't do it. Just the cable box and not all the time. It used to be more frequent with a HDMI connection for audio but since swapping to toslink it's drastically reduced. It only occurs when switching to a multichannel (hi def) program from a mono/stereo (low def) program. It doesn't happen on pause, fast forward or rewind and my cable box doesn't have jump forward or backwards. The UMC-200 volume for mono/stereo (low def) content is around 25/30 and it's not really noticeable unless I listen very closely and the ambient noise is low. The UMC-200 volume for multichannel (hi def) content is often around 35/40 and hence it's a bit more noticeable but not at all intrusive and is frequently masked by ambient noise.

I know it there, it's not intrusive and no one else in the family has even noticed it. As more channels move to hi def it gets even less and we are due for a new cable box next month so hopefully they will have addressed this issue with the latest HDCP handshaking.


Cheers
Gary

[viablex1]

Thanks,

yes mine is pretty loud at any volume and does it with any input or source, including optical or analog etc

I will see what they say tomorrow

Matto

[viablex1]

Long story short emotiva shipped it back, Grayson and Chad were very nice , they got the unit today and are inspecting it etc. So I look forward to see what they have found out and when I will be getting a replacement. Will keep posted.

matto

[victor]

Hi all,

I am a new to the lounge. My UMC 200 has the popping click sound when I mute, change mode, or switch inputs. Did anyone figure out what the issue could be or a solution to this?

I read some threads talking about trying to ground the chassis. I disconnected everything from the UMC 200 but the power cable, connected headphones and i can hear the popping click in those too .. So its pretty much from the device itself

Any input would help
Thanks

[KeithL]

In a situation like that the reason is usually a small DC offset somewhere.

When you apply Mute, or the unit does so internally, it essentially shorts the audio signal to ground somewhere.

In theory, the audio signal is purely AC, and you get a tiny tick, or nothing at all.

However, if there is even a tiny amount of DC on that line, along with the signal, then you get a louder pop (depending on how much DC there is).

In reality, many internal parts include a tiny amount of DC along with the audio signal, and other components are included in the design to block it.

However, as the components whose job to block DC age, sometimes they eventually let a tiny bit leak through.

In other cases, a part like an op-amp or transistor may start out with a really tiny offset, which may get worse as it ages.

(And, with many components, the DC offset may become worse, or sometimes better, as they warm up.)

It won't hurt anything but, as the muting circuitry shorts that DC to ground, and then releases it, you're going to hear a pop.

This can happen because of a tiny DC offset inside the unit... but it can also happen because of one outside the unit.

For example, sometimes the input of an amplifier will leak a tiny bit of DC current.

If so, then every time the source component it is connected to mutes its output, then the DC offset coming from that input is shorted to ground...

(And the result is the same pop... an amplifier will cheerfully amplify the pop caused by its own input leakage being shorted to ground... )

And, yes, it can also occur because of a loose or otherwise poor ground between components...

in which case tightening the offending loose connection may help.

The bottom line is that, as long as the woofer cone doesn't actually jump noticeably, and the pop isn't especially loud, it won't hurt anything.

(In general, unless a noise is much louder than the loudest music you ever play, it usually won't hurt your speaker.... but there are exceptions.)

BUT, since it can come from many different places, it can be difficult to pin down, and may be difficult or impossible to fix.

May 22, 2020 8:58:15 GMT -5 victor said:

Hi all,

I am a new to the lounge. My UMC 200 has the popping click sound when I mute, change mode, or switch inputs. Did anyone figure out what the issue could be or a solution to this?

I read some threads talking about trying to ground the chassis. I disconnected everything from the UMC 200 but the power cable, connected headphones and i can hear the popping click in those too .. So its pretty much from the device itself

Any input would help
Thanks

[victor]

Ok thank you Keith! It definitely makes sense. Probably a leakage of DC through Vds/ drain

Do you think you would know where the muting circuitry is? If it's a matter of an aging transistor, I can try to swap it for another with the same spec. That would mean to know roughly where the transistor might be located on the circuit board. If I can fix that, I think lots of people on this thread may benefit from the solution, but of course that would mean to look at the actual circuit design.

Thanks again for the quick reply

[KeithL]

I think you're sort of missing the point - which is that the muting transistors themselves could potentially become leaky.

Or they could be working perfectly - and the pop could be caused when they mute some some DC offset originating in an upstream component.

(And the pop itself really is not a big deal.)

However... if you really want to see what the muting circuitry on the outputs of the UMC-200 looks like....

May 22, 2020 11:47:09 GMT -5 victor said:

Ok thank you Keith! It definitely makes sense. Probably a leakage of DC through Vds/ drain

Do you think you would know where the muting circuitry is? If it's a matter of an aging transistor, I can try to swap it for another with the same spec. That would mean to know roughly where the transistor might be located on the circuit board. If I can fix that, I think lots of people on this thread may benefit from the solution, but of course that would mean to look at the actual circuit design.

Thanks again for the quick reply