[00birdy]

I've started to notice a static like noise in my left ear, it is more apparent while audio is playing, but occasionally I'll hear the static when I having nothing playing. Certain songs make it more noticeable I am guessing based on different frequencies, but it is getting worse to the point where I notice it almost all the time now.
Anybody have a clue if this is something worth diagnosing and repairing or do I need to go drop another $180 on a new pair. I'm in the SE MI area if there is anyone around with help or recommendations for service.
Thanks

This song is particularly harsh on it.

 

[GREQ]

First try a different headphone or buds/IEM, anything you have lying around to make sure it's not the headphone but perhaps the device.
Or try the same headphone on a different device.

If you still have static on other devices, it sounds like the driver has hair stuck to the front of the diaphragm or it's slowly kicking the bucket.

 

[00birdy]

I tried the headphone from my S9 phone which isn't really strong enough for the 250ohm but anyway I was barely able to notice the static in the left, if I wasn't looking for it I wouldn't have noticed. Didn't have any other headphones at the moment to try on the TubeDAC but I think it's ok.

I've also noticed it seems to come and go, sometimes it will happen on certain parts of songs and other times it will not be there.

What would be the next thing to look for in the driver or diaphragm?

 

[GREQ]

If your hair is getting stuck to the diaphragm, it should already be noticeable underneath the foam, but I would do a full tear down and get to the driver just to make sure.
I once had a faulty set of beyers to work on from a friend, and somehow his cat-like hair managed to get through the foam, through the white paper and the diaphragm was just COVERED in this stuff... I think it's a rare problem but extra cursed when it occurs because of the sticky doped surface that beyerdynamic applies to their drivers.

The black retainer ring under the earpad will just pop off with a large flat-head screwdriver and some 'external' force... just be careful to not tear the paper directly underneath the foam and retainer ring.
The driver is only held down with 3 plastic clips, and they're some of the easiest and best constructed I've ever had to deal with, so that should be a cinch.

 

[00birdy]

Problem gets a little weirder, just received a new set of DT 1990 Pro headphones today and I am noticing a similar static noise in the left ear again. Do I need to send my grant tubedac-11 off for service or maybe this is just some Windows background noise issue.

I've just noticed turning my volume knob during playback seems to greatly increase this static noise I'm hearing. I have it running through USB currently.

I screwed around with the dial a bit and static moved over to the right ear. I've turned it down to about 25% and found a nice spot on the dial that seems to have eliminated all static for now.

Found an old post about cleaning the internals, not sure I know enough to do any of that myself

 

[GREQ]

Sounds like the potentiometer (or 'pot') for the volume control might just need a bit of cleaning.
One would have to open it up and spray some deoxit (or other electronic contact cleaning spray) onto and inside the component and do a number of full rotations back and forth (with the power turned off of course).

 

[00birdy]

Just a quick update on this for anyone else that finds this through google or where-ever.
I was watching some youtube videos on Deoxit and people were arguing in the comments about whether pots should be lubricated with cleaner solvents. Unsure if I should go full blast at the DAC that is only about 5 years old, I tried just using some regular 3M dust cleaner first. Everything looked fairly immaculate when I took the lid off, so I felt a little more confident in not going so harsh right off the bat with solvents. Happy to report no noise or static issues at all. How does head-fi feel about lubes on pots? Should I add some, or leave be?

 

[GREQ]

I'm no expert, but I've had good results applying deoxit type sprays onto volume control pots, but I've only used this on vintage receivers and vintage headphones with pots.
In these cases, it's also more than likely the scratchy, intermittent sound was not simply "just dust".

With your modern DAC, it's extremely unlikely any corrosion has occurred yet, unless you live in an extremely humid climate, and even then it's unlikely at this age.

 

[00birdy]

Yeah the complete lack of dust was very surprising, I'm not sure what caused it but still not having any problems. Is it worth buying a replacement pot just to have around incase it is some other early sign of failure? Or were you thinking it was unrelated to the pot, and caused by something else entirely

 

[GREQ]

After using electrical cleaning spray on vintage pots I've not had any trouble with them since, so I see no reason to believe decent analogue components shouldn't last a hundred years with care every decade or so.
There's usually no reason to have spare pots unless they succumb to irreparable physical damage.

Seems like you've already fixed the issue with the dust spray, but the dust itself would be VERY fine, and trapped inside the pot.
Sometimes they're quite tricky to treat, as you've got to find an opening in which to spray the stuff into, and then clean up the mess after.

The other possibility is that the dust was in there since it was manufactured, some factory dust, and from whatever use it's had recently the dust has been dislodged or blown out.