Cayin HA-300MK2 - humming noise with HD800s

[guzkiy]

Hi all,
posting here as a new member I don't have permissions for other threads.
I need some help and advice with regards to my new Cayin HA-300MK2, just arrived new.
when I turn on the amp, no inputs connected, I hear a humming noise in my Sennheiser HD800s phones (300 omhs impedance). The noise level does not depend on the volume knob position. I tried the usual hygiene:
- moving away from wifi/anything else that can interfere
- clearing the tubes contacts
- added power conditioner
- tried a plug without a central pin
The noise stays and it is not audible when the music plays but audible enough to annoy me without music.
Also, the noise is audible with high impedance dynamic headphones (HD800s) and not audible with planar headphones (HiFiMan 1000se).
Is that something to be expected from this amp?

(I have an option to exchange it with the dealer but i am not sure if the new amp will fix the problem.)
Appreciate your help!

 

[mudnut]

Welcome!

Not an expert by any means, but I've experienced my share of humming noise from tube amps. If it's buzzing or staticky, it's usually ground loop noise or the amp not working properly. Humming noise, however, is caused by either the transformer and/or the tubes. The HD800S may just be inherently too sensitive @102dB for the Cayin amp - exchanging it for another would likely not solve the issue. As long as the noise isn't audible while music is playing, I'd just accept it as par for the course of owning a tube amp. Before that though, I suggest reaching out to your dealer and Cayin and see what they say.

 

[dynamic headphones]

no, hd800s should not hum with the cayin ha-300, is this hum there when u have a dac connected too? u mentioned u can't hear it during music but u also mentioned it was when nothing was connected
is the noise only on one side? have u tried switching the tubes if this is the case and seeing if the noise follows?

 

[guzkiy]

The noise is on both channels. It is there even if no source is connected, so any source-induced noise can be ruled out.
I tried switching tubes just in case, it did not help.
Also added power conditioner, did not help either.

Can please someone who owns Cayin HA-300MK2 and any similar dynamic headphones can confirm that there is no noise from the amp?

 

[dynamic headphones]

The noise is on both channels. It is there even if no source is connected, so any source-induced noise can be ruled out.
I tried switching tubes just in case, it did not help.
Also added power conditioner, did not help either.

Can please someone who owns Cayin HA-300MK2 and any similar dynamic headphones can confirm that there is no noise from the amp?

is the noise equal on both channels? my ha-300 has 0 noise with hd800s, i had a noise problem but that's gone now

 

[guzkiy]

Thank you for your reply!
The noise is equal on both channels.
How did you fix the problem?

 

[dynamic headphones]

Thank you for your reply!
The noise is equal on both channels.
How did you fix the problem?

ur noise is to my knowledge most likely a problem with the transformer, contact ur dealer if everything else is ruled out. have u had tube amps before with no issues?