BasX A-5 buzzing noise

[balint]

Hello there! I recently purchased a BasX A-5 amplifier.
I set it up and it worked great, everything was perfect for a day.
The next day I noticed pretty significant buzzing coming from my media cabinet.
It turns out the A-5 suddenly started producing a buzz that got louder, became quiet suddenly and then loud again. I could faintly hear the buzz even from the next room so it really ruined the listening experience.

The speakers continued to be silent with no noise coming out of them. Only the unit itself was buzzing. I disconnected the unit with only the power left on, and it was still buzzing.
Tried a different socket in a different room, the buzzing continued. I contacted the retailer about it and sent it back so they can take a look at it, however they could not reproduce the issue.
The unit was dead silent in the shop. This left both me and the retailer clueless of how to resolve this issue.

I read that the issue might be with the electric current in my house though I had no means of checking that before.
Does anyone got a suggestion on how to test or diagnose the problem? I was thinking of getting a multimeter however I am not sure what to test for in case the problem is in the power lines of my house.

[KeithL]

I can think of a few things it could be...

1)

It could be mechanical hum from the power transformer.

This could take the form of a slight vibration in the case of the unit - which might not be noticeable at the shop but could cause the shelf it sits on to vibrate.

(Felt pads under the fete might help that.)

2)

Similarly.

It's possible that the magnetic field from the transformer is causing something sitting on top of the A5 to vibrate a little bit.

(Check for things with steel case panels right above the A5.)

3)

DC offset on your power lines could cause the transformer in the A5 to vibrate and hum more than usual.

If so our CMX2 power line filter could fix it.

To test this you need to use a digital meter and check your AC line on the DC RANGE.

(You would be looking for a fraction of a volt of DC on your AC power line - which can be caused by a load imbalance somewhere on the line.)

MOST digital meters will allow you to set them to a low DC range and connect them to a 120 VAC power line... but MAKE SURE.

If you try this with a meter that is not rated for that capability you WILL burn out the meter.

4)

You could have distortion on the actual AC power waveform.

Or you could have some sort of noise on the AC waveform.

If the power sine wave is distorted that distortion can cause the transformer in the A5 to "sing" or "buzz".

Unfortunately this is something that is not simple to test for.

A line filter MIGHT help with this - or it might not.

Jan 19, 2022 11:48:51 GMT -5 balint said:

Hello there! I recently purchased a BasX A-5 amplifier.
I set it up and it worked great, everything was perfect for a day.
The next day I noticed pretty significant buzzing coming from my media cabinet.
It turns out the A-5 suddenly started producing a buzz that got louder, became quiet suddenly and then loud again. I could faintly hear the buzz even from the next room so it really ruined the listening experience.

The speakers continued to be silent with no noise coming out of them. Only the unit itself was buzzing. I disconnected the unit with only the power left on, and it was still buzzing.
Tried a different socket in a different room, the buzzing continued. I contacted the retailer about it and sent it back so they can take a look at it, however they could not reproduce the issue.
The unit was dead silent in the shop. This left both me and the retailer clueless of how to resolve this issue.

I read that the issue might be with the electric current in my house though I had no means of checking that before.
Does anyone got a suggestion on how to test or diagnose the problem? I was thinking of getting a multimeter however I am not sure what to test for in case the problem is in the power lines of my house.

[balint]

I tested the unit in a separate room sitting on the bed matrass. There were no other devices around, and the powerline was on a different circuit.
There must be something going on with the power in my house then. Strange though that no other devices such as receivers exhibited this issue.

Thank you four your reply!

[cawgijoe]

Jan 19, 2022 13:36:40 GMT -5 balint said:

I tested the unit in a separate room sitting on the bed matrass. There were no other devices around, and the powerline was on a different circuit.
There must be something going on with the power in my house then. Strange though that no other devices such as receivers exhibited this issue.

Thank you four your reply!

Can you bring it to a friend's or neighbor's house to try? Are you using a surge protector or just going directly into the wall?

Just some thoughts....

[balint]

It's going straight to the wall. However I tried with a surge protector too. No change. It's already in the shop, and apparently the issue doesn't come up there.
Now I'm contemplating if I may want a refund of there's no simple solution and it's already sitting where I bought it from. I wonder if there's anything worth trying still though cause I really liked how it sounded and I'd like it to work.

[balint]

Jan 19, 2022 12:14:49 GMT -5 KeithL said:

I can think of a few things it could be...

1)

It could be mechanical hum from the power transformer.

This could take the form of a slight vibration in the case of the unit - which might not be noticeable at the shop but could cause the shelf it sits on to vibrate.

(Felt pads under the fete might help that.)

2)

Similarly.

It's possible that the magnetic field from the transformer is causing something sitting on top of the A5 to vibrate a little bit.

(Check for things with steel case panels right above the A5.)

3)

DC offset on your power lines could cause the transformer in the A5 to vibrate and hum more than usual.

If so our CMX2 power line filter could fix it.

To test this you need to use a digital meter and check your AC line on the DC RANGE.

(You would be looking for a fraction of a volt of DC on your AC power line - which can be caused by a load imbalance somewhere on the line.)

MOST digital meters will allow you to set them to a low DC range and connect them to a 120 VAC power line... but MAKE SURE.

If you try this with a meter that is not rated for that capability you WILL burn out the meter.

4)

You could have distortion on the actual AC power waveform.

Or you could have some sort of noise on the AC waveform.

If the power sine wave is distorted that distortion can cause the transformer in the A5 to "sing" or "buzz".

Unfortunately this is something that is not simple to test for.

A line filter MIGHT help with this - or it might not.

Jan 19, 2022 11:48:51 GMT -5 balint said:

Hello there! I recently purchased a BasX A-5 amplifier.
I set it up and it worked great, everything was perfect for a day.
The next day I noticed pretty significant buzzing coming from my media cabinet.
It turns out the A-5 suddenly started producing a buzz that got louder, became quiet suddenly and then loud again. I could faintly hear the buzz even from the next room so it really ruined the listening experience.

The speakers continued to be silent with no noise coming out of them. Only the unit itself was buzzing. I disconnected the unit with only the power left on, and it was still buzzing.
Tried a different socket in a different room, the buzzing continued. I contacted the retailer about it and sent it back so they can take a look at it, however they could not reproduce the issue.
The unit was dead silent in the shop. This left both me and the retailer clueless of how to resolve this issue.

I read that the issue might be with the electric current in my house though I had no means of checking that before.
Does anyone got a suggestion on how to test or diagnose the problem? I was thinking of getting a multimeter however I am not sure what to test for in case the problem is in the power lines of my house.

Unfortunately the emotiva dc blocker was not sold where I live, however I purchased a different quite expensive power strip capable of filtering out DC. So far the amp has been really quiet. Can only hear a faint buzzing when it's dead silent and I put my ear up to it.
I only wish there would've been cheaper solutions for the problem, since the DC blocker costed me 30% of the price of the amp.
I do love how the A-5 makes my system sound and looks great, so I'm glad this issue could be solved.