Anyone know these headphones? Piezo modelDSR-7.
Jun 3, 2010 at 5:49 PM Thread Starter Post #1 of 8


100+ Head-Fier
Mar 23, 2010
My dad had these since forever, but I can't find any information on them online, at all.
Here's a pic:

As far as their sound goes, they're a bit warm and aren't the most detailed. Bass extension is pretty good; highs are a bit recessed but fairly sharp nonetheless. Imaging isn't so good for some reason.
Anyone know anything about these headphones?
Jun 4, 2010 at 1:32 AM Post #3 of 8
The headband and yoke also look a little like the ones on the Pioneer SE-700 piezoelectric. This is an interesting find whether they operate on the piezo principle or not. If you ever get the urge to disassemble them, have a camera ready. 
Jun 4, 2010 at 2:02 AM Post #4 of 8
Does it say DSR-7 on the other side?
The japanese site says PIEZO/AZDEN had a DSR-7 model that look exactly like yours:
(Still, it would be cool if you had a look at the driver just to be sure...)
Quote: babelfish translation from the japanese site
* Price ¥8,500
* Type dynamic type opening air type
* Diaphragm
* Impedance 200Ω 
* Playback frequency zone 20-20,000Hz
* Allowance input 200mW
* Sensitivity 98dB/mW
* Cord/code 2.5m
* Weight 200g
* Around sale 1976
* Around sale end 1983

Jun 4, 2010 at 8:15 AM Post #5 of 8
Yep, only way to be sure is to peek at the diaphragm. If they're piezo, you'll see a flat piece of dark-silver plastic film. But I'm afraid it's a conventional dynamic.
Jun 4, 2010 at 9:29 AM Post #6 of 8
Man I'm tempted to tear them down now but they aren't mine and I'm not sure my dad would like that.
It does say DSR-7 on both sides. Defective, mind sharing the link to the Japanese site?
Jun 4, 2010 at 7:26 PM Post #8 of 8
Hah, these are indeed the same as what I have. Somehow they got rebranded Piezo.
Thanks for the find. It sheds a bit of light on the origins of these mystery cans.

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