Modding my 770, where to get drivers?
Jul 29, 2008 at 3:53 AM Thread Starter Post #1 of 11

Punnisher

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I'm looking into modding my 770s with some nicer-sounding drivers, and I think Grados will fit nicely, physically and sonically.

Where can I get replacement drivers? I've scoured the net but have found nothing.

Another thought would be buying iGrados and extracting the drivers. I'd sooner do this because taking the drivers out of SR60s will destroy them. I've tried but stopped before doing permanent damage to them.

Thoughts? Any other driver suggestions that are light on bass and overall detailed?
 
Jul 29, 2008 at 9:40 AM Post #3 of 11

b0dhi

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It will most probably sound like turd. Try adding a layer of damping fibre in the rear of the DT-770 enclosure. That should tone down the bass significantly. Blocking the ports will also help.
 
Jul 29, 2008 at 9:03 PM Post #4 of 11

Punnisher

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I've done quite a few mods to my 770s, including vibration dampening on the plastic driver housings, filling the hollow spaces with fiber, etc. There's only so much that can be done for the 770 drivers.

In the orthodynamic thread someone reported trying grado drivers in a closed phone, with good results. They said that bass was increased but overall retained the grado sound.

This makes sense, since there is ample room for the driver to move air. Especially in the 770 housing, where the cups are deep and that space is directly connected to the space in front of the driver and around your ears.

Covering the outside of your Grados is not a good comparison, because you are sealing only one side of the driver, making it impossible for the air inside to move, thus restricting the motion of the driver. This is why there is zero bass when you do this. When you have two separate, sealed but connected chambers of air, the driver is free to move and transfers air from one chamber to the other, with little restriction.
 
Jul 30, 2008 at 12:07 AM Post #5 of 11

nikongod

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I put Grado SR-125drivers in a beyer shell.

Its an interesting combination, with some parts of the DT-770 sound staying, and some parts of the SR-125. To agree with punisher, there is no lack of bass. Not QUITE as much as a DT-770 proper, but more than the sr-125 had stock! All in All I do like it, but would not really recommend it unless you have a basket-case DT-770, and dont mind the risk of totally destroying a set of grados.

FWIW, My shell was at one time a 600-ohm DT-770. It sounds pretty good with only a 1/2" cube of foam from a pelican case for damping. The DT-770 is not a sealed headphone, there is also a hidden port.

First and foremost: not all beyer drivers are the same size. PWNED! The 80-ohm drivers are FAR too large unless you want to go all jerry-rigged and glue the grado drivers in. I have never seen a 250-ohm driver so I cant say.

If you have an enclosure that you think will fit them:

If necessary, carefully remove the beyer driver from its "mount." It probably requires removing a little hot-glue and stuff. The stock grado driver in my headphone fit in with acceptably little play, while using all of the stock beyer mounting tabs.

You remove the grado driver ENTIRELY from the tube. this probably requires cutting a couple slots in the tube and breaking it off.

Then you will see an obvious step where the "protective mesh" that goes against your ear on the driver attaches to the actual driver. I used a dremmell and CAREFULLY cut the rim of this in about 6 or 8 spots equally spaced around the driver. Do not cut too deeply into the actual driver!

Remove the cover. My memory places this somewhere breaking the cover into little pieces, and peeling it off. Did I mention you have a good chance of destroying your headphones? Now is a good time to break off a chunk of plastic and simultaneously poke a hole in your driver
wink.gif
dont do that.

If you were lucky&careful enough to successfully get the grado driver "naked" without screwing up the speaker, and planned well for the size of the beyer shell, the grado drivers will drop into the housing.

beyersmile.png
 
Jul 30, 2008 at 3:43 AM Post #6 of 11

Punnisher

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I do have the 80 ohm drivers, but I don't mind doing the work to make them fit well.

I have imagined what it would take to extract the drivers, based on my experience with almost trying it with my extra pair of sr-60s.

I think the iGrado would be a better bet, as it seems they are easier to disassemble. I just hope they use the exact same drivers, otherwise I'll be very upset.
dt880smile.png


It would be such a shame to let the lovely and robust 770 housings go to waste. I think I'll get the iGrados and give it a try. Besides, any Grado makes the 770 sound like a kids toy. Time to fix that.
 
Jul 30, 2008 at 4:51 AM Post #7 of 11

b0dhi

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Quote:

Originally Posted by Punnisher /img/forum/go_quote.gif
Besides, any Grado makes the 770 sound like a kids toy. Time to fix that.


Why is that? Are you aware that the DT-770, 880 and 990 all share the same driver, which is in the same league (in terms of quality) as most Grado drivers?
 
Jul 30, 2008 at 5:02 AM Post #8 of 11

zyxwvutsr

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Quote:

Originally Posted by b0dhi /img/forum/go_quote.gif
Why is that? Are you aware that the DT-770, 880 and 990 all share the same driver, which is in the same league (in terms of quality) as most Grado drivers?


Wow, that's pretty interesting. Would you mind putting up some links so I can do some further reading?
 
Jul 30, 2008 at 5:15 AM Post #9 of 11

ericj

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I don't know for sure that they're the same driver, but they sure as heck all share the same major drver technology traits, which have been consistent in beyer premiumline headphones since 1980.
 
Jul 30, 2008 at 7:53 AM Post #10 of 11

b0dhi

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Quote:

Originally Posted by zyxwvutsr /img/forum/go_quote.gif
Wow, that's pretty interesting. Would you mind putting up some links so I can do some further reading?


That info is from when I was talking to the Beyer repair guy. I asked him if he could order the newer 880 drivers for my pre-2005 990 and he said the drivers are all the same, its just the driver cradles, enclosures and damping is different between models (and impedance ofcourse).
 

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