Orthodynamic Roundup - Page 30

These Soviet headphones have definitely got my interest. No more of the overpriced collectible Yamaha crap, Yay!

More Oktava headphones under the second column here:

http://www.oktava3.narod.ru/

Small addition to the pricing of original Soviet phones:

TDS-7 Amfiton: 47 rubles
TDS-5/5m: 55 rubles

55 rubles in mid-80s was a substantial sum. Starting pay the M.D was 110 rubles a month; a nurse in a hospital, working full-time, was paid 90 rubles/month.

I have own all those phones but TDS 16; have never seen Octava Electrostatic, not ever heard of them. TDS-4 Start were the very cheap dynamic variety; TDS-1 often had magnets un-glued after even small jolt. TDS-7, indeed, was most uncomfortable piece I have ever tried, nothing even come close. I agree what TDS-5 were, by far, the best ones (what's why I kept 'em).
Eugene

Now I need to go back to my sources and figure out what these Oktava headphones were, now you got me thinking that maybe they were electret, and not electrostatic.

Wualta,

No, I don't know the difference between TDS-5 and 5M . As for open back - personally, I always preferred closed phones. To me, open-back types by itself defeats the whole purpose of the headphones, which is to me, privacy. If I am not concern about sounds, then I will not use 'phones. (On the same token, nobody builds open-back speakers anymore (worth listening, that is). Yes, there are Quads, and I don't like them ether).
Eugene

I was not able to find exact specifications of TDS5 and TDS5m, but from members, owned both models, i understood, that 5M are more sensitive...but sound is almost the same.

http://rapidshare.com/files/30498676/tds.djvu


This is a table, taken from Russian hi-fi forum, of mostly type produced Soviet Union headphones, and their analogues from West side of the Wall, but at Russian.. its not so hard to see TDS models and other ones :O))

First column: model name of Soviet Union made heaphoned TDS = ТДС
Second column: type of driver, used in headphones
Third column: foreign analogues
4th column: resistance, Ohm
5th column: inequality of frequency characteristictic of sound pressure at frequency range 20Hz-20Khz, db
6th column: sound pressure level @ 500Hz, at 1 mW power, db
7th column: technical passport power, W
8th column: weight (without cable), kg
9th column: type of connector
10th column: Additional data ( mostly what is included with heaphones)

wualta, actually at this chart are 4 types of drivers, used at headphones: isodynamic, orthodynamic, and 2 sub - types of dynamic. I didnt know what is the difference between isodynamic and orthodynamic.

Isodynamic (Изодинамический): TDS7, TDS15;
Orthodynamic (Ортодинамический): TDS5, Echo TDS 16; TDS19; H-21C; H-25C;
Dynamic, based on capsules (динамические на базе капсюля): TDS13C (H13C); TDS14; TDS17; TDS20; TDS22; TDS23; TDS24; H-27C; H-29C.
Dynamic, based on small speakers from GD series (динамические на базе головок)
( I know this, because I had also TDS3, opened them, and saw real small speaker):
TDS3, based on GD-50; TDS4, based on same GD-50; TDS6, same GD-50; TDS10, based on GD-54; TDS18, same GD-54.
Interesting, a lot of them using same drivers, for example GD series, but specifications are different... Big mistery for me, may its a dampening or something else?

I took a pictures, to show the dampening of TDS16...

A side of driver:


B side of driver with some glue on them:


Dampening materials:


Actually, very primitive, compared to AKG K701, but this construction can resist another World war.. and in some areas, they sounds better IMHO, to my ears, then K701.
Also for my girlfriend, they sound more pleasant then K701, and she have a very good hearing...Compared to K701, this are really small sized headphones.
She prefers them especially for rock music, and R'n'B, likes their bass punch, quitar sounds and detail resolution, so count her also new member of team orthodynamic :O))

T40 experimentation

Well, I finally tore the foam dome off the fronts of my T40.

I also got thinking about the reflex disc, and the first likely material to fall into my hand was self-adhesive aluminum foil.

I went with a reflex stripe, about 5mm*20mm, horizontally across the back of each driver (adhered to the scuzzy floor felt).

Sounds good! I agree that our friend Inkmo should tear the foam dome off his T40 as well. It's the easiest ortho mod yet!

The reflex stripe is a mixed success. I can hear what it's doing, it's good, but i wish it were doing more of it. Right now I'm trying to decide if i want to explore it a bit more by using a wider stripe, or two of them. Or if maybe i should just go with a nickel-sized dot like wualta uses.

One of the reasons I balked at the idea at first was because I got a little confused. My EA RP-15 has an identically designed (albeit smaller) foam disc on the front! I wonder if, in its case, that disc is helping things? Well.. I'm not about to take these apart. The Fostexen on the other hand...


Hey, btw guys. Have any of you Fostex peeps had problems wit the right channel cutting in and out, attenuating? I think mine has to do with the cable. It seems the plastic nubby-guys that screw into the socket on the left cup are a little scored, so I think it might just be wiggling loose.

edit: Oooh. cookiemongering. I'll take a cookie pleeze.

Oh, one thing I also found out: The mini to mini cord that came with my iAudio U2 fits into the Fostex cup exactly. It's a little thick for my RP-15 (shame because it's a perfect length).

I guess I'll just have to do some experimenting on my own and see what the deal is with the Fostex cable. Worse comes to worse I order a new one.

I have a pair of T-40's. I bought them from a member here and they were discussed for about two pages on this thread. I promised him I wouldn't mod them though, so I'm living through you guys. Man are they power hungry.

Well, on the RP21, the foam dome is not very tall, about 1/3rd what the fostexen have. Seemed to be mostly just an effort to put the foam only over the driver and not over the filtered vents around it. haven't seen the RP15 in person so i can't really compare.

I have not had that problem. It's also possible that the jack is damaged or defective. The thing is the plug shouldn't be able to move around much, locked in like that.