[PDOT]

I got a pair of Yamaha HP-3. The drivers of the headphones are small. There is a few of low-bass but mid-bass is more than enough. HP-3 sounds like «analog»: not very detailed, soft sound with good general macrodynamics. It is very good for old hard rock, for example Deep Purple, Black Sabbath, etc. I’ll try to mod it.

 

[spritzer]

Quote:

Originally Posted by smeggy /img/forum/go_quote.gif I don't think it's particularly impossible to make magnetic 'stators' like we have in 'stats by using rigid thin supermagnets rather than the thick, weak and sparsely perforated magnets we're all familiar with. It would take a good dose of R&D and cash to do but certainly not out of reach if some company were to take an interest. Molecularly etched and bonded traces on mylar or similar and you could probably even reproduce a dynamic orthostat made to the same design specs as a stat less the high voltage. Sure it's be inefficient and a pain to drive but what ortho isn't? With the new design you'd be open to much bigger drivers and new housing designs to optimize them. Technology in such things is vastly superior now than in 1975 and much more advanced manufacturing techniques are available. If only someone with cash and influence was around to make them.

It's certainly possible to do something like that. The only trouble is supporting the magnets properly but that can be overcome. Another ESP idea that has never been tried (AFAIK) are wire stators. Very hard to make given the tolerances we must work with but can be done. Then there are ribbons to think about.

 

[Markse]

Hi, thought you might be interested in viewing the insides of these so here's a pic:

There's an interesting sort of wave guide to redirect the back waves out the holes in the side of the back housing, and a small disk of foam as damping.

Mark

PS that magazine was Hi-Fi news & Record Review which was one of the pioneering Brit Hi-Fi mags dating back to the 50's . I have lots of issues from the 50's and 60's which was the heyday of classic Brit hi-fi, but unfortunately not many from the 70's which would have been more interesting for classic headphones.

 

[Faust2D]

Quote:

Originally Posted by PDOT /img/forum/go_quote.gif I got a pair of Yamaha HP-3. The drivers of the headphones are small. There is a few of low-bass but mid-bass is more than enough. HP-3 sounds like «analog»: not very detailed, soft sound with good general macrodynamics. It is very good for old hard rock, for example Deep Purple, Black Sabbath, etc. I’ll try to mod it.

Cool. I believe Ericj was modding his YH-3 and posted some pointer in this thread.

 

[ericj]

Quote:

Originally Posted by Markse /img/forum/go_quote.gif There's an interesting sort of wave guide to redirect the back waves out the holes in the side of the back housing, and a small disk of foam as damping.

That's very interesting. they apparently put some thought into how they were handling the backwave.

the driver module is interesting as well - the magnets and from what i could see the trace on the diaphragm are very much like the SFI tweeters we've been playing with and several of the smaller orthos - but this is the first time we've seen one with a black housing.

Is the housing on that driver metal or plastic? Can you measure it and tell us the dimensions?

 

[facelvega]

Quote:

Originally Posted by ericj /img/forum/go_quote.gif That's very interesting. they apparently put some thought into how they were handling the backwave. the driver module is interesting as well - the magnets and from what i could see the trace on the diaphragm are very much like the SFI tweeters we've been playing with and several of the smaller orthos - but this is the first time we've seen one with a black housing. Is the housing on that driver metal or plastic? Can you measure it and tell us the dimensions?

Looks like plastic to me. Up until we saw that driver housing, it might have been an AT driver in there, but this housing and the wonky omnidirectional parabolic cone for distributing backwave are new to me. But I don't get it-- why is every ortho except the PMB100 and the last-gasp Yamaha so deathly afraid of just having an open back? It seems like it would have been much easier than the rather ingenious solution we see here.

 

[ericj]

Quote:

Originally Posted by facelvega /img/forum/go_quote.gif Looks like plastic to me. Up until we saw that driver housing, it might have been an AT driver in there, but this housing and the wonky omnidirectional parabolic cone for distributing backwave are new to me. But I don't get it-- why is every ortho except the PMB100 and the last-gasp Yamaha so deathly afraid of just having an open back? It seems like it would have been much easier than the rather ingenious solution we see here.

the old T50 as well - but i'm as puzzled as you are. maybe they thought that a sparsely vented enclosure would help keep up the SPL?

 

[ludoo]

I found some time to mod the little Pioneer SE-MJ3B I had in a drawer at the office, and the results are pretty good, definitely easier to tune than the AKGs. The Pioneer is a mostly closed phone, as there are small holes surrounding the mirror finished disc with the Pioneer logo. The case resembles a bit the one of the Eagle orthos from a few posts back, minus the inside cone.

What I did was butcher the baffle, then glue the SFI drivers so that they protrude a little, then apply two layers of damping: a small felt disc in the hollowness in the rear of the cup (you can't see it in the pics as it merges with the white bluetack that covers the inside of the cup) and a disc of open cell foam on the back of the driver. My reasoning is that the foam allows a bit more movement to the driver than the felt, as it's much more elastic. It could take a bit more as sometimes the bass gives the impression of not being as tight as it could be, but whatever I tried adding just killed the bass, and muted the volume. I will probably try a folded paper towel when I feel like opening them again. No damping on the front of the drivers, as I tried a disc of AKG foam and it mutes the highs too much.

Sound is pretty good, at least to my newbie ears, and it fits Spritzer's description of how his Koss hybrids sound, minus the chassis resonances.

Now back to the AKGs, and I'll try to buy the Pro30 that surfaced on ebay (but please tell me if you are going to bid, as I will look for something else) as I'd like to have a "proper" ortho.

 

[wualta]

Quote:

Originally Posted by billinkansas /img/forum/go_quote.gif I find the midrange ambience of the modded YH-1, and even my unmodded YH-2 absolutely seductive. I have not heard that in any stat, and I've had many of them now. The orthos don't have the treble clarity and "sparkle" of the stats, but they do trump them on the bottom end.

And this from someone with two SR-X Mk 3s!

I wouldn't have thought the orthos had an edge in midrange reproduction, but if that's the case, that's the case. I'll only slip in one more suggestion to try a reflex dot to crank up the top octave to 'stat level. Isodynamic treble isn't quite as smooth as 'stat treble, but it can sparkle and it's demonstrably smoother and clearer than any dynamic (upper limit: $350) I've heard. All isodynamics droop in the high treble (including my Monsoons), so this is not a suggestion strictly for us oldsters.

Quote:

Originally Posted by facelvega The ortho soundstage problem is real, but maybe smeggy is on to something with his new frame concept.

Most of this is due to the vented-closed back design all the manufacturers stubbornly used except of course for Fostex's perverse T30 and antiperverse T50. The Eagle is the only one of vented-closed designs that makes any sense, and as you pointed out, even it, clever as it is, isn't necessary. All power to The Smegster and anything he (or anyone else) can do to come up with a 'phone that simply exhausts into free air.

Quote:

Originally Posted by facelvega I don't get it-- why is every ortho except the PMB100 and the last-gasp Yamaha so deathly afraid of just having an open back?

Quote:

Originally Posted by ericj the old T50 as well - but i'm as puzzled as you are. maybe they thought that a sparsely vented enclosure would help keep up the SPL?

Why were they afraid of the open back? I think the mfrs. listened to the bassy droopy sound of the middle-range drivers in free air and found that a closed, reflective back had the nice quick cheap effect of boosting the treble, so they said "To hell with it! it's cheap and it's quick! Make it!"

As JadeEast found when he went to Stage Two with his Pro 30, further damping/tinkering was necessary to reflatten the sound once the back was opened.

Quote:

Originally Posted by scompton If I had something that could drive them well at work, it'd probably be true there as well. I need to find an inexpensive, small amp for work.

Interesting that you prefer the ortho to the SR-5. How small an amp do you need? Would something like a panasonic SA-XR10 be too big, keeping in mind that you can tip it up on its side? 17" wide, about 1.5" thick. I've heard the T-amp isn't suitable for driving headphones because of a DC offset problem too small to affect speakers.

Quote:

Originally Posted by PDOT I got a pair of Yamaha HP-3. I’ll try to mod it.

Excellent! Eagerly awaiting your results and impressions.

By the way, have you ever owned or listened to an Echo H-16?

Quote:

Originally Posted by spritzer Another ESP [electrostatic headphone] idea that has never been tried (AFAIK) is wire stators.

Ah, yes, using insulated wire, like the original JansZens and Acoustats. Good point-- why, other than cost, was this rational, proven, arcproof design never used for other electrostats, much less 'phones? A rant for another forum..

Quote:

Originally Posted by Markse There's an interesting sort of wave guide to redirect the back waves out the holes in the side of the back housing, and a small disk of foam as damping.

Wow, that's evidence of someone doing some cost-effective thinking. Thanks for the pictures, and jeez, did Fostex make that driver (just kidding-- it looks like the capsule in the T50, only smaller), and where can we get about a dozen of these?


.

 

[Faust2D]

Well, I have re-modded my T20v2 and now gotten much closer to what I wanted to achieve in the first place. I replaced the blue foam with the black foam in the back of the cups and cut small hole in the middle of the yellow fake chamois.

I sloppy diagram for your viewing pleasure:

 

[facelvega]

Quote:

Originally Posted by Faust2D /img/forum/go_quote.gif Well, I have re-modded my T20v2 and now gotten much closer to what I wanted to achieve in the first place. I replaced the blue foam with the black foam in the back of the cups and cut small hole in the middle of the yellow fake chamois.

How do they fare up against your YH-1 now? Or against my SR-X?

 

[spritzer]

Quote:

Originally Posted by wualta /img/forum/go_quote.gif Ah, yes, using insulated wire, like the original JansZens and Acoustats. Good point-- why, other than cost, was this rational, proven, arcproof design never used for other electrostats, much less 'phones? A rant for another forum..

It is used by Sound Lab, Audiostatic and some others that make real electrostatics... not chic toys like ML, and works very well for them. The technique has never been adopted over to headphones though. headphone drivers do not suffer from the same size related issue as speakers but it could be a fun experiment. The supporting frames are going to be a problem though as the D/S gap is so small.

 

[wualta]

Quote:

Originally Posted by Faust2D Well, I have re-modded my T20v2 and now gotten much closer to what I wanted to achieve in the first place. I replaced the blue foam with the black foam in the back of the cups and cut small hole in the middle of the yellow fake chamois. I sloppy diagram for your viewing pleasure:

Glorioski!

So now-- what? the response is nice and flat? bass is uncompromised?

Why'd you cut the hole in the [microfiber?] fake chamois? and why a square hole?

Good sloppy diagram, by the way.


Quote:

Originally Posted by facelvega How do they fare up against your YH-1 now? Or against my SR-X?

Or your YH-100. Shoo! Scoot over there straight away and do a blitzenminimeet.

Haha, I'm just joking. You can't shoo in NYC. It just isn't done.

Quote:

Originally Posted by spritzer It is used by Sound Lab, Audiostatic and some others... The supporting frames are going to be a problem though as the D/S gap is so small.

That's good news about others using JansZen's old idea. The last time I seriously looked into ESLs, everyone but Acoustat was using perforated sheet metal, and now that I think about it, that was at least 20 years ago.. [size=xx-small]["yikes" emoticon here][/size] And yeah, scaling it down might be a problem.

.

 

[scompton]

Quote:

Originally Posted by wualta /img/forum/go_quote.gif Interesting that you prefer the ortho to the SR-5. How small an amp do you need? Would something like a panasonic SA-XR10 be too big, keeping in mind that you can tip it up on its side? 17" wide, about 1.5" thick. I've heard the T-amp isn't suitable for driving headphones because of a DC offset problem too small to affect speakers.

That amp would probably work sitting on end. I just have limited desk space. I've been looking at vintage, but they're all too big. Right now, I have a Super T and a Magnavox stat and AT electret transformers stacked on top of each other. A smallish vintage amp or preamp would be ideal, if such a thing exists.

 

[Faust2D]

Quote:

Originally Posted by facelvega /img/forum/go_quote.gif How do they fare up against your YH-1 now? Or against my SR-X?

Quote:

Originally Posted by wualta /img/forum/go_quote.gif Glorioski! So now-- what? the response is nice and flat? bass is uncompromised? Why'd you cut the hole in the [microfiber?] fake chamois? and why a square hole? Good sloppy diagram, by the way.

Well, I got a bit of the mid/low bass back, other then that they are still flat. They got more bass than YH-1 now, I think about the amount that YH-100 had. They are still not as flat as SR-X and not as fast, but much more relaxed and have bass punch like no other. There is a sweetness / smoothness to YH-1 mids that even YH-100 or Lambdas don't have.

I cut the hole in the chamois to get some of the bass back, basically the middle portion of the driver now has only blue felt/foam/back felt in the back damping. The rest of the drive also has chamois. it was a stupid idea but surprisingly it worked. Kinda like an window in damping. Why square? Well I cut a round one first but did not like what I had, so I cut a square one, a bit bigger and got the desired result. Now I am not touching it since it sounds good.