Chris19
100+ Head-Fier
- Joined
- Feb 5, 2009
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Hello all,
I couldn't find a "how-to" thread on wiring up the Ultrasone Pro 900's for balanced, so I figured I'd make one myself. Please note that this is still very much in progress, since I don't have all of the pictures yet, but it will be complete soon.
Tools required:
Wire stripper
Wire cutter
X-acto knife (for cutting away the blue PVC jacket around the cable)
Soldering iron and solder
Multimeter (for figuring out which set of wires is connected to which speaker)
Pliers for holding hot XLR or 1/4" plugs
A drill with a few bits; preferably a small, medium, and larger set of bits to get the right size.
Optional: heat shrink and heat shrink gun
For this mod, I bought some Blue Dragon bulk cable from Moon Audio since it's conveniently wrapped.
Nice cable. It's flexible, slim, and shielded.
I peeled back the blue jacket so you can see all of the internals of this cable. Top layer is a thick blue coating (PVC?) which I had to cut away with an X-acto knife, followed by a nice braided wire shield. Underneath that is a tight wrapping of aluminum foil, which holds the four individual stranded conductors together. There is also some cotton string running along with the wires underneath the aluminum foil, which you can see peeking out. The wires themselves are individually coated; 2 in clear jackets, 2 in white. All in all, very nice!
Since these are stranded wires, put solder on the end of them after stripping so the conductors don't fray.
The Pro 900's have a detachable cable, which screws into the bottom of the left earcup, and is only a 3 conductor design. So, we can't have balanced operation with a cable that fits into the same jack. It's gotta go. Take off the earpads and unscrew the 4 screws which hold the driver board to the plastic earcup. (Picture coming!)
The green plastic piece is the actual jack. I don't know why some people call it a "diode board," as the diodes are soldered to the speakers themselves. Maybe it's different for some models. Anyway, all this jack does is provide soldering points for the internal wires that connect to the speakers. It's just held down by 2 black screws. Unsolder the wires connected to it, then get a tiny screwdriver and pull the sucker out. Sorry -- I don't know why I didn't take a picture of it still in the earcup.
This next portion is provided if you want try out single-ended operation first. Otherwise, skip down to images of the drilled-out earcup.
With the jack gone, the opening is big enough to just put the whole Blue Dragon cable in. If you just want to test this out without going whole-hog, you can wire up the speakers like I did. Red wire for plus, gold for minus (or ground). Since the Blue Dragon has two sets of clear and two sets of white jacketed wires, I'd recommend using, say, white on the plus side, and clear on the minus for each channel. It doesn't matter what color jacket corresponds to the plus or minus, but it helps to be consistent.
Before hooking up the other wires, check the other end of the cable with your multimeter to see which two wires are actually soldered to the speaker. If you use the resistance setting (ohms), probe the wires until you get a reading around 40 ohms. Mark the wire pair, or put electrical tape on them, or anything else that will help you remember which set of wires goes to which speaker. You don't want to accidentally pair the - left channel and + right channel.
Using the other cable which routes through the headband, again use the red wire for the other plus channel, and gold for the other minus/ground.
Note: If you intend to run balanced operation with the single-entry cable and using the wires built into the headphone, that's fine! But I would recommend de-soldering the diodes that are placed across the + and - of each speaker. The diodes are there to protect the speaker from higher voltages than it is spec'd for, and are supposed to dump too loud of a signal directly to ground. Think of diodes as a one-way street; they only allow current to flow in one direction. These diodes only turn on once a sufficiently high voltage is reached, thus dumping the "dangerously" powerful signal to ground, bypassing the speaker entirely. I don't know what will happen if you run a balanced signal to the speaker without removing the diodes first. It might not work at all.
Not shown: for temporary strain relief of the cable, you could just tape the wire down with some electrical tape, but be very gentle when handling the headphones. I wrapped the Blue Dragon cable in some leftover nylon wire wrap and pinched it down beneath the metal driver board.
I tested this out first as single-ended. Put plenty of solder on the quarter inch plug so that you can get a good connection. Mine is sloppy since I didn't intend to leave it this way.
Not too bad looking if you leave it this way.
So let's recap what we have so far:
1. Prep your cable by stripping back the cover with an X-acto knife and wire strippers, and tin the ends
2. Open up the earcups
3. Desolder the wires from the little green plastic input jack, and unscrew the jack
4. Wire up one speaker at a time, checking on the other end of your cable to see which wires correspond with which channel
5. If doing balanced operation with the single entry cable, you must remove the diodes from both the left and right speaker. This will involve an extra step of opening up the right earcup, since the diodes are on the underside of the speaker.
6. Solder on your 1/4" plug / XLR / whatever connector, and you're golden!
Balanced operation section
So now some of you are saying "what's the point of recabling if you're still using the same internal wire?" Fair enough!
The right cup is identical to the left cup, minus the input jack on the bottom. But, it still has a molding where the jack could be. This is a nice point to drill into, don't you think? Oh, and this is definitely bye-bye warranty time, in case we haven't already voided it, which we probably have. Please, please take a moment to unsolder the cable if you tried it out as above. We have to unsolder it anyway, and you don't want the drill to get away from you and into your poor cable.
First picture is head-on with the hole, second is at an angle so you can kind of see the depth of it. The plastic is soft and not at all hard to drill into. Just use a very small bit to get a nice, centered starting hole, and use progressively bigger bits to bore it out. This hole is a bit too small; I want to make it bigger so I can fit my nylon wire covering inside.
The Blue Dragon is one single cable. I want to have dual entry, so I can wire directly to the right speaker. I hope you still have that X-acto knife, because you're going to need it. Slice carefully down the length of the cable for a foot and a half, or maybe two feet (2/3 of a meter), like so:
This is to make the single cable into a Y cable. Don't make it too short or you'll feel like you're choking yourself when you put the headphones on (or at least feel really annoyed with them). When measuring, hold the end of the cable up to at least the middle of your ear (this is important!), and then pinch the spot on the cable where you'd like the Y-joint to be, going from a single cable to the split.
Don't push too hard; the covering is soft, and you don't want to accidentally slice your thumb. You might feel the braided shield underneath; don't worry about damaging it, because we have to take that off too. Worry more about dulling your X-acto knife, or slicing the wires beneath!
More pictures are coming, as is the rest of this writeup, but after getting off the amount of the blue jacket that you want, snip away the bottom of the braided shield with a wire cutter, and pull the length of it off the uncovered end. It should come off in one piece. There will be pieces that fall off, so do this over a table.
Next, unwrap the aluminum foil shield. I found an end at the top; it's wrapped in a tight spiral around the cable, like a barber shop pole or a candy cane. When it comes off, it's a long, thin strip, and you have to trim it at the bottom where you want the Y-joint to be.
There are also the cotton strings in there now; just trim those away and be left with the two wires for each channel. It's probably a good idea to cover each 2-wire set with some nylon jacket or Tech flex or something like that. If you do, you can use some heat shrink to make a nice looking Y-joint. If you don't have access to that equipment, you can use electrical tape to hold it all together, but it won't be as nice.
Before you take the old wires off the speaker, use a small Sharpie to mark which contact point is the plus and which is the minus. If you forgot to do this, look for some red coloring in the solder area; that would be where the red wire (plus side) went.
Thread your wires through the new hole and solder directly to the speaker carefully. The solder that Ultrasone used stinks, so get some ventilation!
That's it for the short ending; to be updated later with more pictures and more detailed explanations.
-Chris
I couldn't find a "how-to" thread on wiring up the Ultrasone Pro 900's for balanced, so I figured I'd make one myself. Please note that this is still very much in progress, since I don't have all of the pictures yet, but it will be complete soon.
Tools required:
Wire stripper
Wire cutter
X-acto knife (for cutting away the blue PVC jacket around the cable)
Soldering iron and solder
Multimeter (for figuring out which set of wires is connected to which speaker)
Pliers for holding hot XLR or 1/4" plugs
A drill with a few bits; preferably a small, medium, and larger set of bits to get the right size.
Optional: heat shrink and heat shrink gun
For this mod, I bought some Blue Dragon bulk cable from Moon Audio since it's conveniently wrapped.
Nice cable. It's flexible, slim, and shielded.
I peeled back the blue jacket so you can see all of the internals of this cable. Top layer is a thick blue coating (PVC?) which I had to cut away with an X-acto knife, followed by a nice braided wire shield. Underneath that is a tight wrapping of aluminum foil, which holds the four individual stranded conductors together. There is also some cotton string running along with the wires underneath the aluminum foil, which you can see peeking out. The wires themselves are individually coated; 2 in clear jackets, 2 in white. All in all, very nice!
Since these are stranded wires, put solder on the end of them after stripping so the conductors don't fray.
The Pro 900's have a detachable cable, which screws into the bottom of the left earcup, and is only a 3 conductor design. So, we can't have balanced operation with a cable that fits into the same jack. It's gotta go. Take off the earpads and unscrew the 4 screws which hold the driver board to the plastic earcup. (Picture coming!)
The green plastic piece is the actual jack. I don't know why some people call it a "diode board," as the diodes are soldered to the speakers themselves. Maybe it's different for some models. Anyway, all this jack does is provide soldering points for the internal wires that connect to the speakers. It's just held down by 2 black screws. Unsolder the wires connected to it, then get a tiny screwdriver and pull the sucker out. Sorry -- I don't know why I didn't take a picture of it still in the earcup.
This next portion is provided if you want try out single-ended operation first. Otherwise, skip down to images of the drilled-out earcup.
With the jack gone, the opening is big enough to just put the whole Blue Dragon cable in. If you just want to test this out without going whole-hog, you can wire up the speakers like I did. Red wire for plus, gold for minus (or ground). Since the Blue Dragon has two sets of clear and two sets of white jacketed wires, I'd recommend using, say, white on the plus side, and clear on the minus for each channel. It doesn't matter what color jacket corresponds to the plus or minus, but it helps to be consistent.
Before hooking up the other wires, check the other end of the cable with your multimeter to see which two wires are actually soldered to the speaker. If you use the resistance setting (ohms), probe the wires until you get a reading around 40 ohms. Mark the wire pair, or put electrical tape on them, or anything else that will help you remember which set of wires goes to which speaker. You don't want to accidentally pair the - left channel and + right channel.
Using the other cable which routes through the headband, again use the red wire for the other plus channel, and gold for the other minus/ground.
Note: If you intend to run balanced operation with the single-entry cable and using the wires built into the headphone, that's fine! But I would recommend de-soldering the diodes that are placed across the + and - of each speaker. The diodes are there to protect the speaker from higher voltages than it is spec'd for, and are supposed to dump too loud of a signal directly to ground. Think of diodes as a one-way street; they only allow current to flow in one direction. These diodes only turn on once a sufficiently high voltage is reached, thus dumping the "dangerously" powerful signal to ground, bypassing the speaker entirely. I don't know what will happen if you run a balanced signal to the speaker without removing the diodes first. It might not work at all.
Not shown: for temporary strain relief of the cable, you could just tape the wire down with some electrical tape, but be very gentle when handling the headphones. I wrapped the Blue Dragon cable in some leftover nylon wire wrap and pinched it down beneath the metal driver board.
I tested this out first as single-ended. Put plenty of solder on the quarter inch plug so that you can get a good connection. Mine is sloppy since I didn't intend to leave it this way.
Not too bad looking if you leave it this way.
So let's recap what we have so far:
1. Prep your cable by stripping back the cover with an X-acto knife and wire strippers, and tin the ends
2. Open up the earcups
3. Desolder the wires from the little green plastic input jack, and unscrew the jack
4. Wire up one speaker at a time, checking on the other end of your cable to see which wires correspond with which channel
5. If doing balanced operation with the single entry cable, you must remove the diodes from both the left and right speaker. This will involve an extra step of opening up the right earcup, since the diodes are on the underside of the speaker.
6. Solder on your 1/4" plug / XLR / whatever connector, and you're golden!
Balanced operation section
So now some of you are saying "what's the point of recabling if you're still using the same internal wire?" Fair enough!
The right cup is identical to the left cup, minus the input jack on the bottom. But, it still has a molding where the jack could be. This is a nice point to drill into, don't you think? Oh, and this is definitely bye-bye warranty time, in case we haven't already voided it, which we probably have. Please, please take a moment to unsolder the cable if you tried it out as above. We have to unsolder it anyway, and you don't want the drill to get away from you and into your poor cable.
First picture is head-on with the hole, second is at an angle so you can kind of see the depth of it. The plastic is soft and not at all hard to drill into. Just use a very small bit to get a nice, centered starting hole, and use progressively bigger bits to bore it out. This hole is a bit too small; I want to make it bigger so I can fit my nylon wire covering inside.
The Blue Dragon is one single cable. I want to have dual entry, so I can wire directly to the right speaker. I hope you still have that X-acto knife, because you're going to need it. Slice carefully down the length of the cable for a foot and a half, or maybe two feet (2/3 of a meter), like so:
This is to make the single cable into a Y cable. Don't make it too short or you'll feel like you're choking yourself when you put the headphones on (or at least feel really annoyed with them). When measuring, hold the end of the cable up to at least the middle of your ear (this is important!), and then pinch the spot on the cable where you'd like the Y-joint to be, going from a single cable to the split.
Don't push too hard; the covering is soft, and you don't want to accidentally slice your thumb. You might feel the braided shield underneath; don't worry about damaging it, because we have to take that off too. Worry more about dulling your X-acto knife, or slicing the wires beneath!
More pictures are coming, as is the rest of this writeup, but after getting off the amount of the blue jacket that you want, snip away the bottom of the braided shield with a wire cutter, and pull the length of it off the uncovered end. It should come off in one piece. There will be pieces that fall off, so do this over a table.
Next, unwrap the aluminum foil shield. I found an end at the top; it's wrapped in a tight spiral around the cable, like a barber shop pole or a candy cane. When it comes off, it's a long, thin strip, and you have to trim it at the bottom where you want the Y-joint to be.
There are also the cotton strings in there now; just trim those away and be left with the two wires for each channel. It's probably a good idea to cover each 2-wire set with some nylon jacket or Tech flex or something like that. If you do, you can use some heat shrink to make a nice looking Y-joint. If you don't have access to that equipment, you can use electrical tape to hold it all together, but it won't be as nice.
Before you take the old wires off the speaker, use a small Sharpie to mark which contact point is the plus and which is the minus. If you forgot to do this, look for some red coloring in the solder area; that would be where the red wire (plus side) went.
Thread your wires through the new hole and solder directly to the speaker carefully. The solder that Ultrasone used stinks, so get some ventilation!
That's it for the short ending; to be updated later with more pictures and more detailed explanations.
-Chris
