[JadeEast]

I had ignored this pair of headphones for too long. They were sitting waiting for some attention... for years. I was dreading the idea that I had a dead driver as I had a weird rattle before they lost sound in one ear.. but after disassembly and testing the drivers both had similar resistance... turns out the internal wiring from the removable cable (not sure this was the first headphone with removable cables but seems like it could be based on era) was just crappy. The rattle was from the loose headphone cable jack in the headphone. Tightened that up and the rattle is gone.

Added a touch of sorbothane to the housing inside and some open cell foam in front of the driver. Foam helps with the low end a bit and the comfort as the foam pads are a bit less resilient than they were. I'm thinking about trying to fabricate replacement ear pads now as at some point they are going to flatten out more and more overtime and the headspeaker aspect will continue to diminish as they sit closer and closer to the ear.

Still sounds good.

 

[Feilong4]

@master1s How do you think the Trio KH-92 compares to the Victor HP-D90? I've been hunting for a pair of either for a while and am very jealous

 

[WallofHooligans]

Daaamn, I've seen a few of these examples on the Japanese market a few times, but the costs just get astronomical for my blood.
I have a feeling you're not the type to want to look inside, but I'd love to see the driver from the hp-d90

 

[micon]

Are the TDS-16 really equivalent of Yamaha drivers?

The TDS-5 sounds good, almost like the HP-1, but the HP-1s sound better. TDS-16 16om are more bassy, they are closer to YH-100 (but don't equate TDS-16 16 with H16-40c, they are completely different sounding and different set of headphones).
I have had a lot of OPTO - IZO models from different countries, I know what I'm saying.

P.S.
I live in a country where a number of models were made from 1984 to 1994. TDS-5, 5M, 7(iso), 16, 15(iso), H-21, H-25c, H-28 , echo H16-40c.
The leading engineer, who studied the first Yamaha model, developed his variants. one of the best was called the Amphiton H-25c, ortho drauvers were as much as 68mm,




the Yamaha 55mm.
in 2015 there was a new and improved version under the name OPPO PM-1.



https://habr.com/ru/company/pult/blog/405691/

 

[Philimon]

YH-2
This example is in great condition with intact pads and non-creaky joints. Stock damping certainly disintegrated but sounds quite nice.

Incoming: Fostex T10. Yamaha HP-1a and YH-1 (both modded by rhythmdevils).

 

[Philimon]

Fostex T10 is much smaller and lighter than expected. Overdamped: fast and lean. Opposite of YH-2. Both smooth and enjoyable.

 

[MDR30]

Found myself, to my surprise, fixing an orthodynamic driver this Saturday morning (haven't opened one for years). Thought I'd share my findings with others having similar driver problems.

In a box laid a disassembled Karstadt K3 (PMB made) with one dead driver. Took it apart and measured the diaphragm, no problem there, so it had to be a bad mechanical contact between membrane and brass ring or centre pin. Cleaned those, assembled the driver - intermittent contact moving the pin. The contact wasn't firm enough. Why? The only conclusion was that the centre washer on the diaphragm was too compressed, probably dried out after 30 years. Cut out a piece of thin cardboard (a bread package), glued it to the washer and assembled the driver. Measured it: working. An hour's work.

 

[micon]

drivers 55mm ?

 

[MDR30]

Yes, 55 mm. There are two versions of the PMB driver, the standard one shown above, and below in the Telefunken TH700:

And also a more elaborate one with more holes and steel plates for stronger magnetic force, used in the Dual DK830 (and possibly Grundig GDHS224):

 

[Philimon]

T10. Stock has two materials for damping. A layer of wool(?) and foam. I am removing the wool in hopes to gain some bass.

 

[leeperry]

@master1s How do you think the Trio KH-92 compares to the Victor HP-D90? I've been hunting for a pair of either for a while and am very jealous

It's all about being at the right place at the right time

 

[JadeEast]

@MDR30 The PMB100 sample I have uses a version of that PMB driver as well... a many holes type magnet but no steel plate.

 

[Philimon]

Hybrid pads. Idea was borrowed from a stratocaster mod.

 

[Philimon]

 

[micon]

THANK YOU to those who show not only the headphones, but most importantly, the essence of sound, the drivers.
I have had and still have many different variations of headphones.
And all of them I open and look at which drivers, in what condition, and whether something can be done to improve the sound.