[khbaur330162]

I gave my pair away to a friend so I'm afraid I can't supply pictures except the ones that I took the day I modded my first pair a few years ago. I'm guessing you saw the original post I made?
 

Meh. I decided to mod my cans real quick and see for myself. Hope you guys like this one, 'cause it was fun to do. 

Started out with stock Sony MDR-CD380:
http://ecx.images-amazon.com/images/...RL._AA280_.jpg

Opened them up and stuck the ATH-2 drivers inside with a bit of wall tak:
http://i8.photobucket.com/albums/a5/...2/IMG_3366.jpg

Took the damping material from previous enclosure and put it into place:
http://i8.photobucket.com/albums/a5/...2/IMG_3368.jpg

http://i8.photobucket.com/albums/a5/...2/IMG_3369.jpg

Stuck the baffle back onto the headband (notice how the damping material is now stuck into place *thumbs up!*):
http://i8.photobucket.com/albums/a5/...2/IMG_3370.jpg

http://i8.photobucket.com/albums/a5/...2/IMG_3371.jpg

Screwed it all together:
http://i8.photobucket.com/albums/a5/...2/IMG_3376.jpg

Stock pads are cloth and probably not suited for ortho's:
http://i8.photobucket.com/albums/a5/...2/IMG_3377.jpg

Unless... (they're pulled inside out and stuck on the opposite driver housing):
http://i8.photobucket.com/albums/a5/...2/IMG_3381.jpg

Finished product:
http://i8.photobucket.com/albums/a5/...2/IMG_3384.jpg


Sound?:

I need to spend more time with them. I literally just did this mod so have had little to no time to even audition them. From what I hear, they sound possibly a little muffled, but honestly, pretty darn good! I'll have to let the Beta22 warm up so I can do some real listening. And it's yet to be determined if this accomplishes what I set out for it to do; increase soundstage.

In the picture where you see the sticky tac around the drivers you also see the damped vents above and below. You have to seal those up which I failed to do in initial mods.
 
As for pads, apart from turning inside out, I just modded the stock pair in order to try and get some extra bass out of them. It closes up the sound considerably, though, so unless you're ok with that I wouldn't recommend it. They sound fine to my ears after simply reversing the pads. Once doing this they're a bit more compact and your ears are very close to the drivers. I never had an issue with just throwing them on my head. The leather pads I stitched for them didn't sound as good as stock. I sourced the leather from an out of commission couch and it was pretty thick stuff.
 
The SFI drivers are a perfect fit. I ended up filing down the little tabs that keep the drivers from falling through the baffles in order to mount them flush. Gets the drivers another mm closer, or so. If you plan on the CD380 housing being their new home I'd use epoxy putty to mount and seal everything.
 
I don't think sealing the baffle to the housing is necessary in this case. You won't be able to do anything about backwave unless serious modifications were in order which I don't recommend or see as necessary. 
 
Interested to hear your report and see what else you can do with them. They are very sturdy cans and I loved them as knock-arounds or even for the occasional critical listening session. They're SFI's, so of course the detail is there. I've thought about another CD380, or even CD280 as it looks near identical, to mod up another pair. I recently slapped those same ATH-2 drivers you see in the pictures into a Sony wraparound frame. Not bad at all, but after a few hours my ears are hurting. I miss the SFI-380, tbh. Probably the perfect compromise between SQ and money, imo. $20 for the drivers, $20 for the frame, 2 hours of modification and you're done... for life. Run. Run away from this place and never return. 

 

[nick n]

Just realized I have the CD-370 which would explain why you had no fit issues. These ones, which are quite a bit different.

Still thanks for the additional info on the 380's I may have to find a dirt cheap pair .
 

 

[capnreverb]

There are lot of pages here to scroll through so I apologize if this is redudant. Fostex made some amazing "ribbon" mics in the 80's using their own technology they called "printed ribbon". They made headphones that used that technology as well, and I think those are the t20, t40, t50's. If thats the case, then are these mics to be considered "orthodynamic microphones"? I have one of these mic's and it is one of my favorite mic's.
 
I also own a set of vintage t40's new in the box that i cant seem to pop the cherry on and try, they look so cool in their box. I bought them because I liked the mics so much.

 

[khbaur330162]

Ooo, dual entry. Those look like fun, too, but yea I can't really help you. I'm not surprised to hear those are a bit quirky in design. The CD380 is odd, too, once you open them up. Never seen anything like them before or after which isn't to say that's necessarily good, or bad. The self adjusting headband is cool, like you mention, and the 380's are also built pretty darn well. I'd have no problem throwing them in a bag, or whatever. 
 
I see 380's and 280's on eBay for dirt quite often.
 
 
Okami: Sorry for the delay, magnets.com is still trying to process my request. I guess they have a minimum order for samples...? Bit of a language barrier and I'm sure I'm not helping any.
 
Ultralam arrived. Looks thick. 112 and 140 gsm translucent paper arrived. Looks perfect. If that has pinholes in the print I'm forced to go to Kinkos and make laser photocopies on mylar transparencies.
 
And guess what decided to die on me in the middle of a job? My Dremel... And the company that made it is 100% AWOL from the looks of it. Now I've got to hunt down replacement motor brushes with no real clue what size it accepts. Awesome. Manual you say? Nope, it just tells me not to use my rotary near explosives and such. 
 

There are lot of pages here to scroll through so I apologize if this is redudant. Fostex made some amazing "ribbon" mics in the 80's using their own technology they called "printed ribbon". The made headphones that used that technology as well, and I think those are the t20, t40, t50's. If thats the case, then are these mics to be considered "orthodynamic microphones"? I have one of these mic's and it is one of my favorite mic's.
 
I also own a set of vintage t40's new in the box that i cant seem to pop the cherry on and try, they look so cool in their box. I bought them because I liked the mics so much.

You really should get into those T40's, imo. I'm sure some one here would be glad to violate them for you. And you could consider those mic's orthodynamic, but there's probably a better name. I just took my SFI ribbon tweeters and stuck them into the line-in on my iRiver H320. It picked up sound well, but it's very quiet. With an amplifier I'm sure your T40's could double as mic's easily.
 

 

[wualta]

Fostex wanted their RP mics to be known as Printed Ribbons: http://www.coutant.org/fostex/index.html
 
[KHB: note the slight annulus!]
 
I've never heard a Fostex RP mic, but I understand the output is low, not too unlike a classic "true" ribbon mic, with a similar response curve. I have retained the impression over the decades that the RP mics didn't find a place in every recording engineer's mic closet. If this is incorrect, I'd like to know. I haven't researched this topic in awhile; I'll have another look.

 

[capnreverb]

 
Quote:

Fostex wanted their RP mics to be known as Printed Ribbons: http://www.coutant.org/fostex/index.html
 
[KHB: note the slight annulus!]
 
I've never heard a Fostex RP mic, but I understand the output is low, not too unlike a classic "true" ribbon mic, with a similar response curve. I have retained the impression over the decades that the RP mics didn't find a place in every recording engineer's mic closet. If this is incorrect, I'd like to know. I haven't researched this topic in awhile; I'll have another look.

The response is a bit lower than a lot of other mics, but not nearly as low as some of my other ribbon mics like my RCA bk5b that you can see in my avatar. I think the issue was more that they were kind of expensive back in the day from a company not known for mics and just a tad bit before ribbon mics had their resurgence in popularity over the last decade. Ribbon mics were pretty much non existent, at least new, when the Fostex mics came out, Beyer being the big exception.  A lot of people say they really are not true ribbon mics in the classic sense. It was a new technology. They are getting quite collectable and expensive now, and sound great micing guitar cabs.
 
 

 

[wualta]

Yay BK5B. That's the announce mic we used at WABE-FM back in the '70s. When the station went stereo in '74, we got an all-new all-RCA studio.

 

[khbaur330162]

 
"In order to obtain a low frequency resonance, the edge must be very thin; a rolled edge, shown in figure 3-1, is used to establish a resonance near 80Hz and also allows uniform movement of the centre of the printed coil." 
 
Thanks for the link. Very cool. I wonder why they didn't employ this idea with their headphones. Apart from it just being a big fat flop (creating more problems than it's worth like you were anticipating) the only thing I can think of is the difference in diaphragm size. Perhaps larger diaphragms simply don't need it. I don't see anything in there about a lens, or restoring force, like electret mics. Did I miss that?  

 

[wualta]

Microphone diaphragms lead a different life. Air drives the diaphragm instead of magnets. Generally the wave energy hits all parts of the diaphragm simultaneously, so even if the magnetic field is a little iffy, you won't get twisting and other unwanted motions. In this case, they say the annulus was used to reach a typical resonant point that most directional mics use, and, I suspect, to keep efficiency up-- if the whole diaphragm moves the same distance as the center, more voltage is generated.
 
Wouldn't one of these diaphragms make a fantastic headphone driver? I think so. Well, the T10 driver seems at least inspired by the Printed Ribbon capsule, so I'll calm my mad urges with that.
 
Electret mics use the same restoring force as electret headphones: tension. A lens wouldn't be necessary since we're simply sampling air velocity rather than creating it, but maybe for special purposes..?
 
ADDENDING: To respond to capnreverb: I think you're right about Fostex's place in the mic universe. Expensive, weird (pros don't use anything new until the guy making the most money uses it), and just not different enough from what was already being widely used.

 

[nick n]

Going to send off 3 more to Tyll.
Here's the issues of the night: I usually run a straight eq but bumped down to about -6db @ 8khz to take off the edge on stuff and this is where these new mods realize their full potential ( at least on the SFI's), their sweet spot, and where I tuned them to initially. However, I figured as with any good measurement he'd be testing at neutral, am I right there?
I had to fuss around switching back and forth with the eq on and off while trying out different damping methods on the ear side of things, stuff that would nearly match the complete sound quality of the -6db eq setting but while the eq was off( neutral ) as it will most likely be tested neutral.
 
The earside mods had to be very precise because they would either drop the sensitivity too, lose the sound transparency, or lessen the overall sound qualities. Talk about frustrating. Ended up using a disc of some motherboard tray foam---don't throw that stuff out!--- and some thinner speaker fabric to accomplish this on the Pioneer ( only a few hours later...

)  Leaving the Woodies for one more fine-tuning check tomorrow. I'll just be removing all this anyhow when I get the things back , but I think it's a necessary thing to have to do otherwise testing would be inaccurate and no point.
 
***A little update on the MG Chemicals Silver Conductive Epoxy. : not cheap but probably a lifetime supply unless you are a total clutz, but cheaper than replacement if I could even find the same headphone, works like a hot damn ( whatever that phrase actually means.  Where'd THAT phrase come from? Same with that clutz word.) Used a tiny bit of it to repair a non-solderable contact wire on a hard-to find electret stator which was aluminum. Tested and working fine now.
 Going to also try some similar damping tomorrow on the repaired electret to see about getting some of that olde euro base ( pru-nown-ced "bah-say" ) out of it. 70mm diaphragm has to have some in it somewhere.

 

[wualta]

Silver-loaded epoxy! Glad to hear a conductive adhesive did the job on a reactive metal (aluminium) where high voltages play in the Philips EM 6721 electret headphones, where, if I'm not mistaken, a stiff wire soldered to the stator broke off, along with the tab it was soldered to. 
 
Hope this joint is durable. Silver and aluminum are almost as far apart as you can get on the classic galvanic series tables, but they assume the presence of an electrolyte. In this case, the epoxy should seal the joint enough to keep humidity out. That's what I'm hoping, anyway. Now if MG would only make an epoxy loaded with aluminium or even zincium, my worries would be for naughtium.
In the meantime, laissez les bons temps rouler!  Let that big diaphragm show you some of that wicked exotic euro basé. 
 

 

[maverickronin]

A quick idea to bounce off everyone here...
 
How would 1/8 aluminum with some constrained layer damping like dynamat added to it work as a baffle?
 
Any thoughts?

 

[Mad Max]

Should be fine, but a bit heavy versus ABS plastic, no?

 

[maverickronin]

Its already going to be heavy enough that a little extra won't hurt and I'm working on a headband design to spread the weight out over a large area.
 
Mostly I'm just looking for the stiffest thing I can find that's easily available and easily shapable.  Which would be stiffer, ABS or aluminum?  I got the idea to try aluminum from Tyll's article on the HD25 Amperiors.

 

[crimsonOkami]

maverickronin:  not trying to tell you what you should do or how you should do it, but if you plan to make/design your own headband i seriously suggest taking an element from the sennheiser 650 headband design if you already havn't.
 
http://cdn.head-fi.org/c/c2/c2616df2_PB12-Sennheiser_HD-650_0.jpeg
 
This simple yet sorta odd looking set-up eliminates stress right on top of the cranium where the head is most sensitive, and re-distributes it towards the side of the top of the cranium.