Orthodynamic Roundup

big SS-100 planar drivers for $15? Interesting!

what is the size of the diphragm?

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That's the understatement of the year. WertherDVX is into headphones like Sol Guggenheim was into art.

EJ.

I have 2 pairs of the pro 30s and they sound different one pair had the vents completely covered, 100% sealed over and the other version was as you say open on the side around the badge. This may have helped with the difference between the two I'm not sure. For the removal I just ripped them off with edge of a knife and some needle nose pliers, they are not going back on and look pretty.

Both versions are felted meaning just the driver, no dot or venting dampening. What I can do now is swap in the different driver and baffle with the different backs and try to determine what advantage or loss is a result of the removal of the badge. I will have to do that soon.

Tyre.

I've been in contact with the seller of the drivers and he is interested in selling them to keep the existing pairs of ss-100s running and I think that's pretty cool. I'm pretty sure that there really are no obscure headphones left and that obscure it's pretty relative. As well it's not like manufacturer of the SS100 is an obscure brand or unknown quantity, still I was quite shocked at how high the price went for something that there seems to be so little information about.

Heh, not sure how to look up "cm" in Russian/Cyrillic.

From what I can tell, the ТДС15 is indeed isodynamic, a kinda surprising 16 Ohm, and judging by this shot it is relatively small:
http://www.fierytrance.ru/img/UB502/30.jpg

A product page in Russian: http://www.rw6ase.narod.ru/t/t/tds15.html (Yadda yadda 20~20k, blah blah high fidelity, something about a thinner membrane, and some boasting about its resistance.)

Heh, some random forum dude from last year said: "Two pairs of SS-100's have sold on eBay - the most recent was in December 2005 for about $25. Rare, but not impossible to find."

Cough.

This guy on Audiokarma has 300dpi scans of Sansui brochures, including the SS-100. Surely that would have the driver size in it, but he's the sort who only likes to trade his scans for things that he doesn't have yet. http://audiokarma.org/forums/showthread.php?t=46552

Alright, my curiosity is sated. I'ma go get some chicken soup.

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Thanks for being the first to take this step. Looks pretty cool. A-T gave the Pro 30 a unique back.

And yeah, the next big step is to cut out a hole and fit a stiff screen behind it to hold the damping pads in tightly.

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Pro 30s seem to vary in the amount of "aluminum cap venting" there is, so it's hard for me to guess what their intent was.

Anyone know of a source of that open but very stiff steel "cloth" used to form domes over microphones and other things?

Some photos of the TDS-15 driver coming up.

I'm not certain which side of the TDS-15 we're seeing here. These photos are from a hi-fi/stereo forum in Poland. I believe the face of the driver is on the left, the rear on the right.

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wow, that is one fancy looking driver

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Mcmaster maybe?

It's a kind of fancy headphone. Folds up too. Available in black or light gray. Here's the gray:

I owe an apology to all Pro 30 owners for not noticing that my 20+ year old mod for the Pro 30 has one glaring deficiency amid all its sterling virtues: I didn't specify an extra foam "spring" to press the felt discs firmly against the driver. If you look at the clamp..



..that holds the driver, you'll notice the three prongs that stick up well above the driver's surface. At age 23+, the foam supplied by the factory isn't stiff enough or thick enough anymore to supply sufficient pressure, especially since it's being pushed away by those three prongs.

Duh!

So all you Pro 30 fans need to get hold of some opencell foam about 6 to 13mm thick (I used some 20mm thick stuff which made it unnecessarily difficult to put the cup back together), cut a 38mm circle, and try to balance it on top of the damper disc as you bring the two halves of the cup together... easy.. easy.. NOW!

Whew!

The best thing about this is that it makes the midbass hump go away. So ya gotta do it.

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Those look FANTASTIC. I love the screen back, and the handling of the drivers themselves also has some eloquence about it.

I believe we're looking at a Soviet copy of none other than the Fostex T50.

Right now that's just an educated guess. Let's hope our Russian, Ukrainian and emigre friends can bring out a couple of examples for us.

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So is that in addition to or instead of the smaller disc of foam already in the cup?

My old factory foam disc was flat as a piece of paper anyway, so I've tossed it in my box o' foam things. When it was new it might've been up to the job, but now.. And even if yours looks new, I'd still give it some help with a fresh disc of nice firm opencell stuff.

Here's a photo:



I've added it to the photo sequence showing the Pro 30 damping suggestion (post # 98), even though this particular foam is really too closed-cell to do the job right (ie, supply spring pressure without impeding the flow of air and messing up the damping). For illustrative purposes only.

This is an ideal application for fishfoam.

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I added some more foam to the guts of the pro-30 definitely reduces the bass booming. Listening to Bill Evans "jade visions" the stand up bass sounds nicer than it did before it was a bit too loose and mushy keys sound nice. Cymbals maybe a bit too scHImmerry and keys have a bit of an edge to them but I have a dot directly on the back of the driver. Low level detail is excellent as in " can you guys shut up in the back this is a historic occasion".

Dr W.

I noticed the numbering on the back of your pro-30 drivers. On my pair that I'll call lighter sounding the numbering is 0811 on the heavier sounding driver it's 3828. Maybe they're just some code for driver matching who knows.

By the way, wualta, after listening to some music i decided that the reflex dot on the back of the pro 30 driver really was making it a bit on the bright side.

So i moved the dot so that about 1mm of it is hanging over the edge above the solder tabs. Seems to have maybe reduced the brightness a bit.