Orthodynamic Roundup - Page 782

That sucks BMF..any way to clear the corrosion off ?

Want to sell your T10? Seriously.

No easy way to capture it in a pic, the flash washes it out and it doesn't show up without a flash. I'll try a 300W halogen from the side later.

My concern with trying to remove it is it's right at the edges of the diaphram. I'm fearful of doing more damage than good.

I will probably try Deox-It too, I have it in a bottle with the little brush as well as the aerosol cans. I guess scraping isn't the right word, rubbing it off with a bamboo skewer so it won't scratch the rest of the ring... I'll see if an eraser works too. My KH-83s seemed to "burn" through the oxidation after a good bit of higher level use, so I might try that with these too, but I have to get them playing louder first.




If I find a way, you know I'll post it up. Sucks too because I have a sweet little 6-wire cable with 3.5mm Neutrik from Germania that is perfect for them. I may measure the DCR of my two good drivers and see how close they are. If there within 5-10ohm then I'll swap the two goods together and work on the others later...


EDIT: The issue is that the Mylar on the edge that is supposed to insulate the positive from teh negative was pitted by the corrosion, so I really do need to insulate the spots.

Nope. It takes me a long time (or a lot of antipathy) (or unmistakable redundancy in the face of demand) to decide to sell a headphone.

de-oxit on a swab was able to clean corrosion off the lcd contacts in my Fossil chinese big-tic watch (counts down the seconds in chinese) so i think it may work for headphones too.

There is a product sold at WalMart (and probably similar stores) in the camping goods section that is intended to be used to seal pinhole leaks in vinyl air beds and pool toys and the like. What you get is a little bottle of some sort of polymer in solution and a little brush. Goes on thin, and looks like someone sneezed and wiped their nose on the surface. Cures non-tacky and works surprisingly well on airbeds. This may do the trick for your pitted membrane if applied thin enough.

If I can find my little bottle of it, I'll tell you what it's called. I haven't seen it in years, though.

Edit: to be clear, it is emphatically not a cement, and comes with no little swatches of vinyl. It's literally a brush-on polymer in a little brown glass bottle, and claims to seal small holes in vinyl air bladders in a single application.

i would be weary of deoxit - it has the potential of leaving a residue on the driver surface which may change its characteristics. I used 70% ethanol and soaked the driver before giving them a gentle rub.

The traces can be corrected as described earlier - this is the same fate as the yh1000 and T20 suffered.

You can ship the 2 dud drivers to me if you like, but it is not rocket science so you may just want to have a go yourself..dB

Thanks Don. The traces are perfect. Not even a wrinkle. It's just an oxidation "burned" through the Mylar and the two rings short each other out. It's in tree places, with two other oxidation spots on one ring...

aaah, didn't get that part ..dB

No Worries. Well, I worry because I have to peal the Mylar insulator portion off the cathode ring to seal underneath it... And of course teh wire has no clear nail polish...

Eric,

I know the stuff you mentioned, and actually had something similar in an aerosol as a water proofing agent. I know it was a polymer because the over spray dried on my arm and I peeled it off.

Great idea Wualt, but no worries. My Precious lives! Open heart surgery was successfully completed at approximately 9:47PM CDT.

My P&S Canon just doesn't shoot well at night in my dark office, so no great close ups of Germania's cable, but it fits like a dream. 26Ga stranded SPC Alpha wire, 2 wires to neg, 1 to positive per driver.





Love the fact that the red heat shrink is visible through the slots in the strain relief. Very cool custom touch that was unintended...



They're a little off on the dampening now, the highs are a touch off and the mids a hair recessed on several CDs, but amazing with acoustic sets were the bass and electric guitars don't recess the vocals. Just need to swap a denser felt disc I have on the driver for two discs of cotton...


EDIT: Listening to them now off the Audigy on the PC.

EDIT-2: It's crazy, pure craziness, they sound BETTER on my PC than my CR-620. I'm not touching the dampening until I have my new portable rig, both amp and DAP are being upgraded so I'll have to wait and see what they need for that setup.

excellent news ..dB

I can only imagine how you felt when you heard Kabeer's YH-1Ks for the first time after your work was successful.

Thanks for everyone's help and suggestions. In the end I used Deox-It on the Q-Tip and had to completely pull the Mylar off the 'nodes. A touch of CA and wiped off most of it just to seal both sides of the Mylar, then rotated the Mylar about 10 degrees before restacking and reassembly. K.I.S.S. at it's finest, glorious sound!

I've been around hundreds and hundreds of manufacturing facilities and have had to trouble shoot field failures of equipment caused by environmental conditions at these plants, so here are my thoughts:

My two T10s have similar corrosion, but it's different in each case. It isn't on the diaphram itself, it's on the two rings, the anode and cathode if you will. They were stamped from a carbon steel and either chrome plated (Fostex) or brass plated (Kenwood) for corrosion protection. I suspect my Fostex are newer and Fostex made a flying change to the more expensive chrome plating after they realized the error of their ways as brass still oxidizies and rather quickly when exposed to certain caustics that are commonly used in manufacturing. Anything with chlorine will attack brass, so even exposure to bleach vapors in a house hold can start the process.

My suspicion is that the nodes were not properly cleaned after plating or they were splashed with a different cleaning or machining fluid elsewhere in production. The spots on my Fostex where definitely a zinc oxide galvanic corrosion probably caused by an exposure to an acid at Fostex in manufacturing. It just took 30 years of sitting there to start, then the electrical current from when I played them for the first time in 30 years, provided the charge to burn through the Mylar and create a dead short.

The Kenwood brass nodes have a copper-based galvanic corrosion out of the brass, and it formed a large insulating layer that keep the circuit open. Deox-It removed it enough to get the power flowing and a crank up of the power allowed it to burn through the rest of the way.


I used super glue to cover teh hole on both sides since it's at the edge of the diaphragm where it is powered and not required to flex.

They were thinking only in terms of cost and the minimum required time to cover warranty costs.

I'll try to remember to take a pic of my brass played nodes in the KH-83s when I recable them. Now that I know what to look for, I'll see what else is going on in the 83's driver. They're running the old cable from the 33s though, so it's a low priority since they are working.

I try to avoid walmart so it will be late next week before I'm close enough to one to justify a trip inside.


Sorry, I use a lot of acronyms.