Tube DAC 11 Hum Trouble-Shooting

SimplyOrange

AK Subscriber
Subscriber
Hello.

I just recently noticed a hum when my Tube DAC 11 is connected to my receiver, even when the DAC is off. I've tried several things, including using Deoxit as well as switching cables. But I've traced the issue back to the DAC. I've also tried several inputs on my receiver with the same result only with the DAC. Any input I plug the DAC into causes the humming sound.

The humming sound will actually come out of several outputs. For instance, if it's plugged into AUX, the hum might also come out of the tape outputs at a lower volume.

Nothing else I have hooked up to my receiver causes this sound, even when connected to the same inputs the DAC was previously connected to.

I noticed a large screw and washer at the bottom of the DAC, should I try to ground the DAC to my receiver?

Thanks in advance.
 
Last edited by a moderator:
TubeDAC-11 Hum Trouble-Shooting

Hi SimplyOrange,

This is usually a tube or hook-up related issue, I think it is the 2nd time I have heard of a hum issue with the TubeDAC-11 and the first was a wonky tube.

Do not change the grounding! That bolt on the bottom is the the Toroidal Transformer Mount, do not play with it :)

Here is the typical troubleshooting questions you would get by contacting us directly for support (where we get to say hi to each other). The TubeDAC-11 when hooked up and operating properly will be dead quiet.

Did the hum just start or did you just notice it?

Does it hum thru the headphone jack with nothing plugged in or out of the TubeDAC-11?

Check that the tube is properly seated. If you have another compatible tube try another tube.

If you have another system, try it there.

Does it hum with the volume turned down on the TubeDAC-11, does the hum get louder if you turn the volume up?

Do you have all your gear plugged into the same power bar or wall receptacle? This is highly recommended for any audio (or A/V) system, a single ground point thru one receptacle.

Is your house or the receptacle you are using grounded? Older houses or renovations do need to be checked. We used to joke that the B-283 was an excellent electrical system ground tester.

If using the Tube Out, try the DAC Direct or Solid State out.

Try unplugging everything going into the TubeDAC-11 and see if hum goes away, then reconnect the inputs one at a time until it comes back.

If you have TV cable or Sattelite or a computer network hooked into this system, unhook the cable.

Let us know.

I'll make this a sticky, so that we can have a central thread for troubleshooting the TubeDAC-11

Cheers,
Ian
 
Hey iGrant. I really appreciate your reply.

The issue seems to be resolved. I believe it was an error on my part.

I had a VCR connected to one of the tape monitors in order to play exclusively audio through a VHS. I also had a separate cable connecting the VCR to my television in order to change the menu options. The TV was connected to the same source as my equipment (a voltage regulator/surge protector). Although, the cable box attached to my television was hooked up to a different source (a regular surge protector). The humming issue seem to resolve itself when I disconnected the wire from my VCR to my TV. I just played a CD on a player hooked to the DAC and it seems to work and sound fine now.

The only thing I noticed initially was a bit of crackling out of my receiver's volume control when switched to AUX, which seemed to go away.

If I have any more related issues in the future, I'll make sure to bring it up again in this thread, but for now everything seems alright.

Thanks again for your help.
 
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