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mhdt Orchid - hum noise

Hi all

I have been having issues with my Orchid (again) but this time is more frustrating. I hear a very strong hum noise when the dac is turned on and it doesn't go away, even when playing music, even if the music masks it a little. The noise is very evident and I'm wondering if not working properly and I'm afraid the dac will stop working all together any time. I have changed power cables, connection cables, tried 3 different tubes and the issue is there with zero improvement. The hum gets louder as I turn up the volume.

Did any of you ever experience this issue? 

any suggestion on how to solve it is welcome.

thank you in advance.

Nuno

 

xpress_on
grannyring's avatar
grannyring
6,511 posts
 

Does it only do this on the usb input? 

xpress_on OP
4 posts
 
Hi This started this week, I have the dac for around 1 year and never noticed it before. Let me be clear that this is not negligible, it is loud and it only get worst as I increase the volume, as if a constant hum sound was being plaid. It doesn't matter if there is any sign/music being sent to the dac through any of the digital inputs (USB or toslink or RCA). As soon as I turn on the dac I hear the noise thought the speakers, if I turn down the volume the noise goes away. looking inside doesn't show any issues. I was wondering if it could be something in the tube connectors/solder or indeed in the power supply. :(
peter_s
1,348 posts
 

I think you should send it to the manufacturer for service. He is a straight shooter and will take care of it. even if you have to send it to China. And maybe just buy a used DAC to tide you over in the meanwhile.

grannyring's avatar
grannyring
6,511 posts
 

Linear Tube Audio here in the US can fix it.  Unplug the USB cable and see if it goes away. 

xpress_on OP
4 posts
 

I'm waiting for feedback from the manufacturer. Unfortunately I'm in Europe so LTA may not be the best option but thanks for the suggestion, always good to have options.

I made this little clip:

 

it was playing well for an 1h and after I started noticing this hum once again. I turned off the music when I recorded the clip, actually even without any signal the hum is there. I even test it without any tube and the hum is there. As soon as I turn off the dac, it goes away, turning up and down to volume nob also increases / decreases the audible noise. 

:(

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