[nick n]

Bucket:
 Can you find out what ohms the drivers are at some point? The rating ion the box is what you are plugging into.
 
I would think the drivers themselves are 8, 32, 64, 120 or 150 ohms more or less.
 
If you desolder the tabs and have a cheapo  mulitmeter that is...

 

[BucketInABucket]

  Bucket:
 Can you find out what ohms the drivers are at some point? The rating ion the box is what you are plugging into.
 
I would think the drivers themselves are 8, 32, 64, 120 or 150 ohms more or less.
 
If you desolder the tabs and have a cheapo  mulitmeter that is...

Sure, no problem! As it so happens I was playing about with them and the Argentum already. The right one appears to be 136.5 ohms, the left one 127.7 ohms. Not matched all that well but not too bad for a vintage I guess. They seem to be about as sensitive as the 32-ohm SFI tweeters too.

---

So remember how I was saying the H25 pads were crap? Well, they fell apart when I wore them for 15 minutes. So much for that.

Spoiler: Boo.

 
However, sound impressions were pretty impressive. Nice solid low-end for one thing. There were also no major peaks and the treble wasn't too bad for my standards. Seeing as I was bored, I decided to transplant the Adastra H25 drivers into the Argentum. Initially I went along with the existing damping scheme but it was a bit unimpressive. Bass was stronger but still rather light so I decided to make some changes (yes I'm purely tuning them to improve bass response now).
 

• Drilled small vents onto the side of the cup. Achieved absolutely nothing...
• Removed the fiberglass. Bass quantity increased. What? Adding fiberglass increased the bass when SFI tweeters were still there...
• Going by that logic, removed all felt donuts. Bass became looser, lighter and not so nice in general. Well then.
• Replaced largest wool felt donut. Better.
• Cut out new Arctic Bamboo felt donut (more like rectangle) with a smaller opening in the middle and put that in. Tighter bass, good. Turns out felt is still good for damping.
• Accidentally removed the felt covering the vent. What the hell, they're so bassy now! I call voodoo magicks!
• Put paxmate on the exposed part of the cup and cut a hole in the middle to let the bass port do its work. Slightly tighter bass. Perfect.

 
They still don't have all that much sub-bass (tested with a 20Hz to 20kHz sweep) but they actually play EDM quite well now! Their midrange is better than the D2K's and their treble is excellent. Wow, these Adastra H25 drivers are gooooooood. Money well spent indeed.

Spoiler: Simple damping scheme.

 
EDIT: Feel free to call me an idiot, moron, or whatever other derogatory term you think of for taking apart a practically NOS pair of headphones and transplanting the drivers somewhere else 

 

 

[nick n]

No way you are perfectly justified in transplanting NOS stuff!
 Things are meant to be used. RIGHT?
There are bound to be more around, not like they made a prototype only, so chances are always greater than zero.
 
 
I was going to come in and post about replacement pads that are similar for the Adaestsratsara set. Fabric covered things.  Let me know and i can link you up in a pm or something.
 
THANKS for the readings off the ASDADARSTARDASTRA 's drivers.
 
I found that sometimes if you end up following logical damping patterns it send s me into a corner or two, then it is always the slightest "mistake" or instinct that should not make any sense at the time logically that can pull you out of the dead end damping corner.
 
Just like with artistic things, I find the best stuff comes out of making mistakes and capitalizing on them...
Run on instinct and/or listen to the little voices coming from the other planar dimensional realms....

 

[BucketInABucket]

No way you are perfectly justified in transplanting NOS stuff!
 Things are meant to be used. RIGHT?
There are bound to be more around, not like they made a prototype only, so chances are always greater than zero.


I was going to come in and post about replacement pads that are similar for the Adaestsratsara set. Fabric covered things.  Let me know and i can link you up in a pm or something.

THANKS for the readings off the ASDADARSTARDASTRA 's drivers.

I found that sometimes if you end up following logical damping patterns it send s me into a corner or two, then it is always the slightest "mistake" or instinct that should not make any sense at the time logically that can pull you out of the dead end damping corner.

Just like with artistic things, I find the best stuff comes out of making mistakes and capitalizing on them...
Run on instinct and/or listen to the little voices coming from the other planar dimensional realms....

It does feel a bit bad to take apart something so rare like that though but the yummy bass improvements make it worth it in my book. I PMed you about the pads btw

Oftentimes the best inventions are made entirely by accident, penicillin being one prime example. I agree with you in that sometimes it's best not to follow the status quo (I mean who uses paxmate to damp orthos anyways haha) and instead go off on a whim and do your own thing. It's rather like conducting scientific experiments - in fact this is practically physics anyways - and its enjoyable in the same way that doing science is!

 

[nick n]

While we are on the subject, do you have any pictures of the earside of that driver? Or do you recall if they have the exact same dustguard cover as the rear side you show? If not what does the earside look like?
 Thanks!

 

[dogwan]

  yh3/hp3 is portable but way too powerhungry for portable use. The only ortho I found suitable for running from portable gear is the sansui ssl55 so the ath 2 should be as well, tho I am pretty sure Sansui did something better with the stock config in the cups as I really love my but heard ath2's are quite not good without dampening.
 
How hungry my hp3 is? An ak120 on max volume setting barely made enough of it to be suitable for street use... really.
 
The SSL55 is good from my clip+... with not maxed out volume. While riding a bike in a capital city center.

I've been running my modded HP3's out of an AMB Labs Mini^3. There's not a lot of headroom, but at about 75% on the volume is a comfortable listening level.
 
Granted it's not as convenient as plugging into a smartphone, but a 4th gen iPod classic with a LOD in the mini^3 with ortho magic is great for traveling and a few knowing looks on the bus to campus!

 

[fattyu]

  I've been running my modded HP3's out of an AMB Labs Mini^3. There's not a lot of headroom, but at about 75% on the volume is a comfortable listening level.
 
Granted it's not as convenient as plugging into a smartphone, but a 4th gen iPod classic with a LOD in the mini^3 with ortho magic is great for traveling and a few knowing looks on the bus to campus!

if i was doing public transport a portable amp and hp1 would be my solution But riding a bike presents some other challanges. I love the clip+ sounds fine enough for portable use and the size and clip it to your shirt just rocks for bike riding for example.

 

[BucketInABucket]

While we are on the subject, do you have any pictures of the earside of that driver? Or do you recall if they have the exact same dustguard cover as the rear side you show? If not what does the earside look like?
 Thanks!

No pictures but the earside has the magnet exposed if you get what I mean.

 

[MuZo2]

   

 
Got my pair of heavily modded USSR TDS-15 headphones by doctorhead forum member named snorry. They look pretty hot for my taste and the sound is just gorgeous!

Seems the guy worked on magnets or replaced them with new. Wonder how new magnet strength would work with efficiency of old orthos? 
 

 

[bluemonkeyflyer]

  Seems the guy worked on magnets or replaced them with new. Wonder how new magnet strength would work with efficiency of old orthos? 
 

Neodymium magnets should make vintage orthos more efficient. They would need to be aligned opposing one another.
 
Here's the Fostex T10/20/30 magnet and diaphragm array:
 

 

[MuZo2]

I am still wondering about factors like
Strength of magnets.
Distance between them.
Spacing between diaphragm & magnets.


 

 

[Igenich]

as I remember from what I read at Russian forums this guy using original magnets

 

[Drakkard]

  Seems the guy worked on magnets or replaced them with new. Wonder how new magnet strength would work with efficiency of old orthos? 
 

Original magnets. Plastic driver housing will have trouble holding neodymium structure. I know several guys tried it.
 

  I am still wondering about factors like
Strength of magnets.
Distance between them.
Spacing between diaphragm & magnets.
 
 
 

I did some experiments in this regard. Strength of magnets and spacing between opposite sides mainly affects sensitivity. My results with neodymium - increasing spacing from 0.5mm diaphragm-magnet to 1.5mm resulted in about 6db sensitivity drop.

 

[MuZo2]

Which headphone did you make the test? any pictures.
So for neodymium, it will need metal plates and then maybe screws to hold two sides.
 

 

[Drakkard]

  Which headphone did you make the test? any pictures.
So for neodymium, it will need metal plates and then maybe screws to hold two sides.
 

Not much to show now, possibly later.
And yea, metal with screws works much better.