[littlexx26]

Hi there
I have a question i could not see answered so for in this thread. I received a Niimbus US5 pro for trial from a very nice dealer who let me have the unit for one week.
Although i really loved the sound, the thing that made me send it back was the mechanical hum from the PCB TOROIDAL TRANSFORMER PTC25.
Especially when the unit was cold, the hum could be heard outside close to the enclosure.
I also own a V281 that is actually totally silent. So due to the hum, I sent it back. Now I wonder if any here in the forum have observed something similar?
These are highly rated special transformers, so they should not really be heard through that very massive case.
Comments?

maybe power supply in your place has dc

 

[SalR406]

maybe power supply in your place has dc

Yeah, DC on the mains is a common cause of mechanical transformer buzzing.

 

[iFi audio]

Yeah, DC on the mains is a common cause of mechanical transformer buzzing.

That's correct, but luckily that buzzing sound is easy to get rid of

 

[mikel]

The interesting thing is that the V281 that was connected to the same electrical source was silent.
@iFi audio : can you explain what you mean with „easy to get rid of“?

 

[m-i-c-k-e-y]

A DC Blocker.

 

[swissheadphonelover]

I have not heard any transformer hum from my Niimbus US 5 Pro.

+1

 

[Fegefeuer]

No PSU humming at all. The last time I had humming was with the Gungnir A2. A DC blocker solved it.
I use a Supra DC Power Strip now to prevent it for all devices, however the Niimbus doesn't buzz without it either. Gungnir A2 must have been a little too sensitive.

 

[mikel]

Thanks for those datapoints..... i guess i will see what the feedback from Fried Reim is.
The V281 is on the same eletrical source and is dead silent. What is strange is the fact, that they probably use the same transformers.
My theory currently is a transformer, that is probably not behaving as it should.
My dealer on the other hand could also hear the hum slightly after i returned the unit.... so it is probably not related my electrical source ....
I will let you know how it goes.

 

[drummerdimitri]

Has anyone had their volume knob led light fail?

I had noticed it and opened up the unit to see what was going on and it turns out that the connection has failed at the led's pcb as one of the wires has snapped off.

Shame to see they haven't bothered with strain relief as the wires are flapping around in the breeze so every time one turns the volume knob, all the strain is being applied at the solder joint so no wonder it was going to fail .

Will try to resolder the wire back on so lets see how that goes.

 

[swissheadphonelover]

Has anyone had their volume knob led light fail?

Yes, sent it back to Lake People and they repaired it. So I do not know what was the reason it failed.

 

[Arniesb]

Has anyone had their volume knob led light fail?

I had noticed it and opened up the unit to see what was going on and it turns out that the connection has failed at the led's pcb as one of the wires has snapped off.

Shame to see they haven't bothered with strain relief as the wires are flapping around in the breeze so every time one turns the volume knob, all the strain is being applied at the solder joint so no wonder it was going to fail .

Will try to resolder the wire back on so lets see how that goes.

You were messing around with it didnt you?
Didnt you change the caps? I think you did something yourself.

 

[drummerdimitri]

You were messing around with it didnt you?
Didnt you change the caps? I think you did something yourself.

No I didn't why would I mess around with the LED?

Caps are a different story and have nothing to do with the volume knob.

 

[Fegefeuer]

Hm, no problemo in 3 years now. How did you notice it? Sudden volume rise?

 

[drummerdimitri]

Hm, no problemo in 3 years now. How did you notice it? Sudden volume rise?

Nothing wrong with the volume control, it's the LED on the knob that turned off so that's how I noticed it.

 

[vonBaron]

Niimbus is amazing amp, even with sensitive IEMs.