Head-Fi.org › Forums › Equipment Forums › Headphones (full-size) › How to tell Ohms of beyer 880 and driver/cable issue
New Posts  All Forums:Forum Nav:

How to tell Ohms of beyer 880 and driver/cable issue

post #1 of 9
2/13/12 at 5:00pm
Thread Starter 

So I bought a pair of what I thought were dt880 premium 250ohm headphones on ebay, the right ear not working. When I opened the package the original box says they're the 600ohm version, though this was actually a nice surprise as I've heard great things about the 600ohm set. I figured maybe the guy just used a different box but it also says 600ohm on the plug. Though being skeptical I was wondering if there is any way to tell the difference between 250 and 600ohm version. I will say that there are two resistors on each driver which my dt770/80ohms do not have, but then again they're different phones aren't they?

 

My next issue is that despite checking all the connection inside the phones, they all seem to be fine yet the right driver still doesn't work. I was hoping for a quick resolder and then I have a nice set of phones for cheap but it doesnt look like it's going to be that easy. I'm hoping a replacement driver can be bought from beyerdynamic? This ties into my first question now, since I definitely don't want to buy the wrong impedance driver! Your thoughts and ideas greatly appreciated, as always.


Edited by DaftZomb - 2/13/12 at 5:01pm
Reply
post #2 of 9
2/13/12 at 5:59pm

If you have a digital multimeter (DMM), you can use that to check which model you have using the headphone plug.  I just used my DMM on my DT990/600s and got a reading of 600 ohms.

Reply
post #3 of 9
2/13/12 at 7:48pm
If it says 600ohm on the plug, it's 600ohms. Unless the guy went out of his way to recable it with the stock 600ohm cable, which wouldbe ridiculous.
Reply
post #4 of 9
2/14/12 at 12:53am
Quote:
Originally Posted by DaftZomb View Post

I will say that there are two resistors on each driver which my dt770/80ohms do not have, but then again they're different phones aren't they?


Those are actually not resistors, but Zener diodes, and are used to protect the driver from high voltage spikes. Since the 600 Ohm driver is the most fragile due to the very thin voice coil wire, their presence also suggests that you do indeed have the 600 Ohm version.

 

Quote:
Originally Posted by DaftZomb View Post
I'm hoping a replacement driver can be bought from beyerdynamic?


Yes, this is what you are looking for. Check any other spare parts (including drivers of any impedance you prefer) here. I am not sure about shipping to your location, though. They may also be available elsewhere if you search for the part numbers.

 

By the way, is it possible that the thin cord that feeds the right driver, and goes through the headband, is broken ? Or did you already check that the cables are OK ?

 


Edited by stv014 - 2/14/12 at 1:14am
Reply
post #5 of 9
2/14/12 at 1:42am
600Ω and 32Ω are labelled on the plug. The 250Ω are blank.
Reply
post #6 of 9
2/14/12 at 1:51pm
Thread Starter 

Cool, thanks for the replies everyone. I guess it was silly of me to still think they might have been 250ohm with the marked plug. STV- That's exactly what I've been looking for! I couldn't find that on the American/English site, but I have emailed them so time to play the waiting game. I also have checked the wire running under the headband but sadly it's fine.

 

But get this- I just finished a test to eliminate any faulty existing wire where I wired the stock cable from some 770's to just the right driver. Imagine a naked driver hooked to a cable....and I noticed that there is sound coming from it, though it's VERY faint. It may have had sound when connected properly to the other driver, but I just didn't notice as I had to put the driver right up to my ear with the volume pretty high. Is this just what a blown/dead driver does? Or might this be a sign of the diodes (thanks stv) having failed?

Reply
post #7 of 9
2/14/12 at 2:06pm
Quote:
Originally Posted by DaftZomb View Post
Is this just what a blown/dead driver does? Or might this be a sign of the diodes (thanks stv) having failed?


Since the diodes are connected parallel with the driver, if they fail in a way that they become (almost) a short circuit, then the result could be similar. But a broken driver can also be much quieter (and distorted) than normal. I guess removing the diodes (or just cutting/unsoldering the connection between them to test) can be tried without much risk, as either the diodes or the driver is faulty anyway.

 


Edited by stv014 - 2/14/12 at 2:10pm
Reply
post #8 of 9
2/14/12 at 3:27pm
Thread Starter 
Quote:
Originally Posted by stv014 View Post


Since the diodes are connected parallel with the driver, if they fail in a way that they become (almost) a short circuit, then the result could be similar. But a broken driver can also be much quieter (and distorted) than normal. I guess removing the diodes (or just cutting/unsoldering the connection between them to test) can be tried without much risk, as either the diodes or the driver is faulty anyway.

 



And removed the diodes I did, now there's no sound at all through the driver...? I did accidentally pull out one of the terminals when trying to remove the diode, but I pushed it back into place. I seems that that's how they're put there in the first place though. Ugh, I think it's time to throw in the towel on this one and start throwing money at anyone with a 600ohm driver for sale.

Reply
post #9 of 9
2/15/12 at 12:49am
Quote:
Originally Posted by DaftZomb View Post

I did accidentally pull out one of the terminals when trying to remove the diode


It is possible that the voice coil wire was broken by this, it is very thin and fragile.

 

Reply
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Headphones (full-size)
Head-Fi.org › Forums › Equipment Forums › Headphones (full-size) › How to tell Ohms of beyer 880 and driver/cable issue