Orthodynamic Roundup

[DefectiveAudioComponent]

  Regarding the U70, I didn't find they were so much bass light, it was moreso that they sounded really hot and unnatural throughout the frequency range... it was basically just like my (heavily modified) KOSS Pro/4AAA tonally, with somehow worse transients and higher THD. Compared to my (stock) YH-1, they were damn terrible. They just sort of seemed to sound "off" in some way that I couldn't really describe at the time. 
 
It's weird, since the Magnat RT-10 (menitoned earlier) uses the exact same drivers but somehow manages to be quite nice sounding, at least according to DAC...
 
Which prompted me to start experimenting. I'm working on transplanting them into an Audio Technica ATH-6 shell right now. Here's a WIP shot:
 

 

 
Cheers.

 
The drivers should sound ok if you play them outside of the headset, just holding them in your hands to your ears. If they don't sound good then, I wouldn't have high hopes for a transplant either.
 
The apparent problem with the U70 headset (that I never have heard) is the shallow vented-closed cups. I suppose that would reflect a lot of treble into the ears. I prefer the open-back PMB headsets.
 
That headset looks promising for a transplant - it looks quite similar to the large PMB headsets. Fully open back? I recommend light or no back damping to start with, good ear pads, and getting the driver as close to the ear as possible - even a small distance can reduce bass a lot. Depending on what pads you use, you might even try placing the drivers on the wrong side of the baffle. A bit of damping the front of the driver (dense dust protector) might be useful. (Traditional damping might work too of course, I suppose that's what you have there on the picture?)

 

[nick n]

Was out for the day and by the time I got back to see what the seller wanted for postage here, they were sold.
 
Sawafuji OEM'd previously unknown model by the name of
 


  Oh well I should have done the buy it now, but I am getting stingy. If memory serves me there were some favourable impressions on these things.  By the way they are a clone of the SF-17 .  Someone got lucky today I hope whoever did appreciates what they are.
Just wanted to log this for future reference . Not going to state the name so no searches pick up the info== I'd rather see people who read this or do a bit of research ( a deserving individual ) get rewarded next time instead of some random googull searcher for flogging info, lack of effort, etc.

 

[Hutnicks]

  Was out for the day and by the time I got back to see what the seller wanted for postage here, they were sold.
 
Sawafuji OEM'd previously unknown model by the name of
 


  Oh well I should have done the buy it now, but I am getting stingy. If memory serves me there were some favourable impressions on these things.  By the way they are a clone of the SF-17 .  Someone got lucky today I hope whoever did appreciates what they are.
Just wanted to log this for future reference . Not going to state the name so no searches pick up the info== I'd rather see people who read this or do a bit of research ( a deserving individual ) get rewarded next time instead of some random googull searcher for flogging info, lack of effort, etc.

Those have a real sideburns down to the jaw, bell bottoms look to em. I wonder who retailed them.

 

[nick n]

I think of Ultraman for some reason when i see these, maybe Hotwheels also actually.  Must have been a North American place is my guess. I find it funny that with these rare one-offs that we happen to notice anyhow, that you would think there'd be more floating around somewhere.
 
Gives me hope there are yet more to be discovered still.

 

[Hutnicks]

  I think of Ultraman for some reason when i see these, maybe Hotwheels also actually.  Must have been a North American place is my guess. I find it funny that with these rare one-offs that we happen to notice anyhow, that you would think there'd be more floating around somewhere.
 
Gives me hope there are yet more to be discovered still.
Friggin MCS for example. Only ever seen under a handful of their multiple models total so far.

Theres probably a forgotten warehouse or somebodys basement somewhere chock full of the things.

 

[Kabeer]

Amazing find Nick . I always love new discoveries. A shame you couldn't snatch it up.

Im sure there must be more OEMs flying around. I like the detective work of it all to find them all out. Before the collective effort of this thread and wikiphonia cataloguing all this info was lost to history.
 
Now imagine the OEMs flying around in Japan... they would be even harder to find for us.

 

[takato14]

 

  Regarding the U70, I didn't find they were so much bass light, it was moreso that they sounded really hot and unnatural throughout the frequency range... it was basically just like my (heavily modified) KOSS Pro/4AAA tonally, with somehow worse transients and higher THD. Compared to my (stock) YH-1, they were damn terrible. They just sort of seemed to sound "off" in some way that I couldn't really describe at the time. 
 
It's weird, since the Magnat RT-10 (menitoned earlier) uses the exact same drivers but somehow manages to be quite nice sounding, at least according to DAC...
 
Which prompted me to start experimenting. I'm working on transplanting them into an Audio Technica ATH-6 shell right now. Here's a WIP shot:
 

 

 
Cheers.

 
The drivers should sound ok if you play them outside of the headset, just holding them in your hands to your ears. If they don't sound good then, I wouldn't have high hopes for a transplant either.
 
The apparent problem with the U70 headset (that I never have heard) is the shallow vented-closed cups. I suppose that would reflect a lot of treble into the ears. I prefer the open-back PMB headsets.
 
That headset looks promising for a transplant - it looks quite similar to the large PMB headsets. Fully open back? I recommend light or no back damping to start with, good ear pads, and getting the driver as close to the ear as possible - even a small distance can reduce bass a lot. Depending on what pads you use, you might even try placing the drivers on the wrong side of the baffle. A bit of damping the front of the driver (dense dust protector) might be useful. (Traditional damping might work too of course, I suppose that's what you have there on the picture?)

The damping stuck in there at the moment is one of the two felt/rockwool discs that were in each side of the U70, and yeah they're fully open. Sound impression is basically the U70 with a soundstage, doubtlessly due to overdampening. I'll do more on it later.
 
Using deteriorated Pioneer SE-700 pads at the moment; once crappy vinyl pleather, now a very nice, soft, breathable velour.

 

[DefectiveAudioComponent]

Nice find there with the old SFI orthodynamic 

 
 
Quote:

  The damping stuck in there at the moment is one of the two felt/rockwool discs that were in each side of the U70, and yeah they're fully open. Sound impression is basically the U70 with a soundstage, doubtlessly due to overdampening. I'll do more on it later.
 
Using deteriorated Pioneer SE-700 pads at the moment; once crappy vinyl pleather, now a very nice, soft, breathable velour.

 
Soundstage is a good first step. But with breathable velour, I'd expect that you hear no deep bass at all. If that's the case, then the bass should return if you switch to good leather/pleather pads, that seal perfectly to the baffle - and if you also have a perfectly sealed baffle around the driver. (I'd try without any damping first, to hear how that sounds).

 

[GREQ]

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[DefectiveAudioComponent]

 
Here's the sandwich, ready for instillation.

 
 

 
What part of the headphone is that? Where is the driver? What does the whole thing look like taken apart?
What PMB driver did you find in there?

 

[nick n]

That acoustic foam there, try stripping the adhesive layer off the back and using that directly on the driver, with maybe some thin felt against the driver, then the foam layer on top..  Just a thought.
 Or find some thin memory foam makeup pads instead with felt. Cheaper and easier
 
 
I second DAC's above questions also

 

[takato14]

  I've been waiting a while to play with this one. (after reading about how difficult it is to mod properly, I had a "challenge accepted" moment)
Bang & Olufsen U70.
 

 
Here's my damping scheme.
- Aluminium back plate has thin heavy self-adhesive creatology felt stuck directly onto it.
- paxmate around the circumference of the back plate to radically improve the chamber sealing
- single small make-up pad
- single layer of thin heavy wool (green)
- In the photo above you sort of see the ear pads I'm using - they came off a Watson Mod.930 clone (Dynacoustic SP400v) which are a tiny bit too big, but work great.
I stuck those on with double sided tape, which also serves to seal up all the other holes.
 

 
Here's the sandwich, ready for instillation.

 
This took about 4-5 hours of playing around with various combinations to find something vaguely satisfying.
Am I totally happy? No. 
Do I think it can get any better? Not much.
 
These things can take a tonne of damping and still keep it quite bassy which is great.
The problem was finding something that decreased the mid-bass without killing the mids and highs.
Any sort of felt just turned sound to mud. 
 
The sound I've decided to stick with is actually very dark. TBH every config I tried was dark - getting more treble out of these (with the pleather earpads and paxmate sealing) seems impossible.
But the wool seemed to tame the mid bass without turning everything else to mush. 
 
Curious to know what others have tried with theirs.

Yeah, the U70 really just... idk, I couldn't get anything worth listening to out of those drivers, and I'm STILL not getting much even in the ATH-6 shell. The treble just doesn't seem to exist.
 
As for the U70 itself, my friend loves the look of the headphones. He couldn't even hope to power the stock drivers as he's not an audiophile and has no amp. So for his birthday I took out the PMB drivers and stuck in some old Fostex-made dynamics from a Walmart OEM cheapie, with one of the stock felt discs behind the bass port (which I opened). The result was a very good, warm, inviting sound. It sounds similar to the way the K240 Sextett measures, and it's well detailed. There was something special about it that I couldn't describe; I really liked them and so does he.
 
I did string some speaker cloth over the front of the driver before giving them to him to look more professional; it kind of took away that special sound, but he still likes them so it works. I'm trying to find another pair of those drivers so I can try putting them in something else...

 

[nick n]

did you try a reflex dot or anything like that? Some cotton pads for damping/fleshing up the highs?

 

[takato14]

  did you try a reflex dot or anything like that? Some cotton pads for damping/fleshing up the highs?

Tried every trick in the book, still no treble, doubtlessly due to it being an untensioned, pinned design. Perhaps heating the diaphragm to retension it would prove helpful... which I'd gladly try if it wasn't so dangerous.

 

[GREQ]

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