Dre Beats Studio DIY teardown and modify question...

[NickPDX]

Hello everybody,
 
Let me preface this by saying I would never have paid this kind of money for these headphones.  I am a manager at a retail store and we received an additional set of Dre Beats Studio headphones for our display units.  We generally throw this kind of stuff away because the vendor doesn't want to bother with shipping and they have typically already expensed it out.  So, I wound up taking them home to see if I could tweak them to work without the display unit.
 
So far I have got the glued down battery compartment open and found that the batter slot is there but is not wired for power.  It is getting power through the cord.  The headphone cord is not removable and at the end it splits and has the audio input and the power input spot.  The power switch on the right can was glued and I was able to loosen that up so it will turn off and on now.  I would like to be able to modify this unit and get it so that it has power from the batteries and doesn't require an additional power source.
 
Does anybody have any advice before I go forward and start tearing these down?  Any documents or videos that would show a complete tear down of both cans?  I found a youtube of somebody opening the left can where the mute and power buttons are but nothing for the right one.  I also didn't find anything on ifixit.com.  Everything else I have found has pointed me to this community saying that everything headphone related would be here.  
 
Thanks for any help or advice.  Wouldn't mind being able to salvage these headphones for personal use.

 

[speedystep]

if the battery compartment was glued closed and the wires was not connected, then i guess
you got a sample model for display use.
normally those samples dont work at all, or if they work it is not fully funcionally.
i dont belive they are powered from the audio source you connect.
i havent myself modded or even hear such a pair, they are pretty expensive i Denmark.
so if i got a sample i would take all electronics out and use them as normal passive headphones.

 

[NickPDX]

Yeah it is a sample/display unit.  It is usually hooked up to a powered display head unit.  So far this is what I have discovered.  Plugged into an MP3 player, they do work but very quietly almost can't head at max volume.  If I plug in an AC adapter to the wall and plug them into the headphones they work near perfect while playing from an audio source.  The Mute button works while plugged in and the power switch moves back and forth.  The power switch doesn't actually do anything but move though (doesn't power off).
 
The fixes that I think I am going to have to make.  Rewire the power to the battery terminals instead of AC power.  Probably fix the power switch so that it isn't always hot.  Rewire the headphone jack so it is like the original and can detach at the bottom of the can, existing wire is a bit thicker and has power and sound in one.
 
I found a tear down video on Youtube but only shows the right can being taken apart.  I am assuming that the left can will come apart the same way but not sure what it looks like inside.  I was hoping to find some pictures of the internal components of the speakers before I get in there.

 

[Armaegis]

There's something really wrong if the power switch is running hot...
 
How much voltage is coming off that AC adapter? It shouldn't be anymore than 2.4 to 3 V. (and I dearly hope that's an AC/DC adapter, not AC/AC).

 

[jbserra]

I know this is an old thread, but how did your conversion go?  I'm in the same boat with some old broken demo phones and was hoping to put them back into service.  What voltage is the adapter?  Did you get the batteries to charge?
 
Thanks!

 

[vantt1]

Well since the headphones run from 2 x AAA in parallel, then obviously it needs 3 Volts to operate.
 
Regarding the disassembly; first remove the ear cushions then unscrew the only three screws visible:

 
Then connect up the battery compartment to the headphone jack PCB here:

 
I only have the retail version, so I don't know what the demo version looks like on the inside. Care to share with us some pictures?

 

[vantt1]

And regarding conversion, I've actually already converted my Studios to become Bluetooth wireless headphones.

 
There is a rechargeable Li-ion in place of the battery compartment.

 
And of course, a Bluetooth circuit in place of the original circuit.

 

[jbserra]

Wow, thanks for the info.  I will try to get some pics posted.
 
I have the model with the internal rechargeable batteries.  I'm wondering if it's slightly over 3v to charge them?  Typically they are USB charged, which means they're expecting 5v to charge, right?

 

[vantt1]

Yes, it would seem so. What's on the other end of that fixed un-detachable cable? Is it a 3.5 mm jack plus a DC input?

 

[jbserra]

Yes, that's correct.  I guessed and have 4.5v running to it.  I tried 3.8v but it didn't power up.

 

[vantt1]

Have you tried 4.2V? Lithium ions usually provide 3.7-3.8V operating voltage and charge at 4.2V.

 

[vantt1]

All this info is leading me to think that the demo Beats are actually quite different from the consumer version. Do you think the demos might even be better than the one you can buy?

 

[jbserra]

  All this info is leading me to think that the demo Beats are actually quite different from the consumer version. Do you think the demos might even be better than the one you can buy?

No, I think they are just "tethered" to discourage theft.  The bypass of the batteries, lack of usb charging and required transformer to plug them in definitely doesn't make them better.  I would imagine the rest of the setup is the same.  If they put different speakers or driving circuits in them, then that would be a horrible misrepresentation of their product and would probably land them in legal trouble.  Not that Monster is not used to legal trouble for misrepresentation I suppose...
 
Someone attempted to steal these from a store (or was way too rough with them) and busted the fold point on one of the sides.  The JB Weld is dry and I'm happy to report they are rock solid now and actually look almost like new.  Unfortunately, I can't fold one side, but they are useable again.  Now to see if I can get the batteries reconnected and charging...

 

[jbserra]

I took them mostly apart.  I could tell the usb connector was missing entirely.  The side I opened looked to have a spot for a square battery, but no battery.  I'd have to add the battery and the charging circuit.  I really don't want to break a functional set of Studios, so I think they're tethered to my desktop computer for now.  If I broke them trying to liberate them from the power cord, I'd be more upset.
 
Listening to them right now.  Sound great!  Those speakers look like they're out of a gumball machine.  I'm surprised they sound so good.

 

[vantt1]

Pics or it didn't happen! I might be able to help you in rewiring them.