[Mikeb]

I have an old pair of Beyer DT990 headphones which has started to distort in the right hand side particularly with bass signals I therefore thought I may replace the drive unit however as the phones are 600ohms (as indicated on the box) the UK importer does not have such a unit in stock (only 250 and 80 ohm types), does anyone have ideas. I may consider perhaps replacing both units, would this be feasible and how difficult, and if so which would be best the 250 or 80 version?

Thanks

 

[BushGuy]

New drivers are priced so that you are better off just buying a new headphone..........and for dt990 - the current 2005 600 ohm version is the best of them all.
FWIW - I had cups, headband etc for dt770 and wanted to try 32ohm version......so bought the drivers from Germany. The cost of the drivers was $145.

 

[mosi]

You know that reminds me of my 990's. They also distorted slightly with bass on higher volumes. In fact there were one or two small hairs poking onto the membrane. After I've gotten rid of those things have been fine again.
If you're already thinking of opening them anyway maybe give that theory a try.

Back then I followed the steps for "Grado Rattle" which already made things a little better. Ultimatively there were still hairs on the membrane though. Luckily they became visible (as in poked out of one of the tiny holes) after blowing quite hard into the driver unit through the little holes from the front so I could pull them out with tweezers.
Magnifying glasses work wonders there.

 

[warrior05]

Totally agree with mosi. Open them up and check for anything on the driver. If you do end up replacing them it is a piece of cake swap since Beyer sends you the driver mounted. It is just a matter of unsoldering the two conductors from the old then soldering to the new. I would definitely go 250 ohm rather than 80. It is unfortunate they don't have 600s. My 2005+ DT990/600 is my favorite headphone.

 

[b0dhi]

Hairs seem to fuse to the DT-990 driver for some reason. It's difficult to remove them once thats happened. But if you do end up replacing them, make sure to replace them in matched pairs.

 

[Mikeb]

Thanks for the advice I will open them up and check for any hairs/debris present, nothing much to loose, hopefully I can get them back to normal.
Thanks again for the replies.

 

[Fitz]

Beyer drivers have a unique property of being able to draw hairs to and through them no matter how clean you keep things. I did a double-take the first time I saw a hair poking all the way through a Beyer driver.

 

[ericj]

Quote:

Originally Posted by BushGuy /img/forum/go_quote.gif New drivers are priced so that you are better off just buying a new headphone..........and for dt990 - the current 2005 600 ohm version is the best of them all. FWIW - I had cups, headband etc for dt770 and wanted to try 32ohm version......so bought the drivers from Germany. The cost of the drivers was $145.

When i had to replace a dt770/80 driver a few years ago, it was $47 shipped from michael manny at Beyer USA.

At first it sounded like a mismatch, but after a couple hundred hours of burn-in it sounded fine.

Quote:

Originally Posted by b0dhi /img/forum/go_quote.gif Hairs seem to fuse to the DT-990 driver for some reason. It's difficult to remove them once thats happened. But if you do end up replacing them, make sure to replace them in matched pairs.

Yes, the doping compound on the diaphragm face is actually sticky, and the foam sheet over the grille is a bit like Nerf in the way it can attract and draw in hairs.

There used to be a picture here of a beyer driver with a hair stuck to it that had to be pulled off with tweezers.

And, well, when i had a blown (completely f'ing blown) dt770 driver, the first thing michael at beyer usa asked me was if i'd checked for hairs.

 

[FrozenPanda]

Where can I get in touch with this Michael from Beyer? I am in need of a driver or 2..

 

[FrozenPanda]

They just replied to the email I sent to their support. 
 
Their price for the drivers are:

Part Number: 952283 – DT990 250 Ohm Driver - $56.28 each, plus $15.00 standard UPS shipping and handling.
 
If I get only one driver will there be a difference in sound? My pair is well over 10 years old. Is burnout a boolean effect? Meaning will the sound equalize over time? Or should I really buy 2 drivers.. I mean I guess $127 is a decent manufactuer's price for the pair of drivers for a  $380 pair of headphones..