[RAFA]

Today I received an almost new pair of these Toshiba headphones.
 
They sound unexpectedly good. Especially the mids are very nice. Generally I have not the impression that these headphones are almost 30 years old.
 
The actual problem and my question is: How can I drive these headphones properly?
 
My initial impressions with the HR-V7 are with my Aune T1. I turned the volume knob almost to 100% and still did not feel, as it was powerful enough to drive these? Google does not give enough information.
 
 

 
 
This is a photo of the manual I got with the headphones. It says that it is designed to operate from an output of 400Ohm. This is the first time that I have read that the output impedance must be 400Ohm.
 

 
Help would be appreciated

 

[duncan1]

A Canadian website is selling the same headphones but with a pre-amp -the Toshiba-HR-910. I cant find a circuit diagram or more info on the amp. The only thing you have to watch with an  electric condenser is that over the years the  cap loses its charge -slowly. .107 DB spl at 3V is quite loud  .But that is the original output when new. You would be better trying it on a know high output amp  to check.the difference.

 

[vid]

Electret power!
 
The HR-V7 probably don't need a separate box, see http://20cheaddatebase.web.fc2.com/aurex/JACK.html.

 

[duncan1]

Sorry VID-I dont speak the language which appears to be far eastern  not Chinese or is it Japanese ?? My Russian browser  only translates into Russian.But you are right  it doesnt need a high voltage to  power it as it has its own internal charge. 

 

[vid]

There's a picture of the HR-V7 on that page with its innards spread out. It seems that they have a built-in box of their own.

 

[duncan1]

I see it it shows the step-up transformer that is built in to each driver.  Can you check it on some other piece of equipment to see how it compares to the amp you are using now and could you give me the full name of the amp you are using now so I can see if there is a circuit diagram to see the spec. of it, I notice it also shows a Stax SB7 which I have in black that goes back to the early 80s.  

 

[Chris J]

What I'm going to say is probably totally useless for the Toshibas, but I used to own a 30 year old pair of Signet TK-33 Electret Headphones.
They came with a small adaptor box which had to be hooked up to a power amp.
There were a pair of transformers in the adaptor box.
They were not the loudest headphones in the world, but sounded outstanding at low volumes! 

 

[duncan1]

That makes sense Chris.

 

[RAFA]

Quote:

Electret power!
 
The HR-V7 probably don't need a separate box, see http://20cheaddatebase.web.fc2.com/aurex/JACK.html.

 
From your link I can tell, that there is a transformer for each driver in ther earcups. Also, wouldn't this mean that I do not need an extra box, like the HR910 has? It seems, that I need some extreme powerful amp.
 
Quote:

I see it it shows the step-up transformer that is built in to each driver.  Can you check it on some other piece of equipment to see how it compares to the amp you are using now and could you give me the full name of the amp you are using now so I can see if there is a circuit diagram to see the spec. of it, I notice it also shows a Stax SB7 which I have in black that goes back to the early 80s.  

 
I looked up that Canadian seller of the HR-V7. Sadly he does not show the ampbox on his photos.
 
The amp, that I use is a pretty simple one. The aune T1 is DAC with a Tube DAC-outputstage and a solid state amp (hybrid). Although it drives all the headphones at home very good and I do not even have to crank up the volume, with this one it seems difficult.
 
 
 
Quote:

What I'm going to say is probably totally useless for the Toshibas, but I used to own a 30 year old pair of Signet TK-33 Electret Headphones.
They came with a small adaptor box which had to be hooked up to a power amp.
There were a pair of transformers in the adaptor box.
They were not the loudest headphones in the world, but sounded outstanding at low volumes! 

 
Judging from your comment, I will really have to buy a speaker amp then
 
Thank you all for your replies.
 
EDIT:
 
I thought I should look further in the manual, but it does not say much. There is definitely no talk about an extra box, between tapedeck and headphone.
 

 

 

[vid]

That's a thin diaphragm for an electret. A lot of trets had the transformers built-in to do away with the need for a separate box lying around.
 
You might look into buying a receiver or integrated amp of the same vintage as the phones. That is, if the sound issue isn't due to some defect in the phones themselves.

 

[Chris J]

From your link I can tell, that there is a transformer for each driver in ther earcups. Also, wouldn't this mean that I do not need an extra box, like the HR910 has? It seems, that I need some extreme powerful amp.


I looked up that Canadian seller of the HR-V7. Sadly he does not show the ampbox on his photos.

The amp, that I use is a pretty simple one. The aune T1 is DAC with a Tube DAC-outputstage and a solid state amp (hybrid). Although it drives all the headphones at home very good and I do not even have to crank up the volume, with this one it seems difficult.




Judging from your comment, I will really have to buy a speaker amp then

Thank you all for your replies.

EDIT:

I thought I should look further in the manual, but it does not say much. There is definitely no talk about an extra box, between tapedeck and headphone.

It is true that 30 year old receiver were able to output a lot of voltage via their headphone jacks as the headphone jacks were connected to the power amp outputs via series resistors.

 

[duncan1]

Got the output spec. on the net. Its a good amp with more than -120 DB noise -thats good. But I think the problem is as ChrisJ says= at 32 OHMS you get 1 WATT --at 120 OHMS you get -400 MW and at 300 OHMS you only get -150 MV . .Thats not good enough for an electric headphone so as  Chris J says -you must enter the World of loudspeaker POWER amps. That is exactly the same as early   Stax head phones of the same era.with their transformer boxes [I have one] Must be used with a loudspeaker power amp of around 10 WATTS RMS.=As stated in the Stax information of the original  rectangular Lamba for use with the Stax transformer box.

 

[RAFA]

Quote:

Got the output spec. on the net. Its a good amp with more than -120 DB noise -thats good. But I think the problem is as ChrisJ says= at 32 OHMS you get 1 WATT --at 120 OHMS you get -400 MW and at 300 OHMS you only get -150 MV . .Thats not good enough for an electric headphone so as  Chris J says -you must enter the World of loudspeaker POWER amps. That is exactly the same as early   Stax head phones of the same era.with their transformer boxes [I have one] Must be used with a loudspeaker power amp of around 10 WATTS RMS.

 
Good god, I know where this leads. I will buy an loudspeaker amp and then some monitor speakers. In a year I end up having a 5000€ home setup for loudspeakers.
 
Would something like a STAX SRA-12S help?

 

[duncan1]

No! Dont buy that it has a high voltage output  meant for Stax headphones 350V. Like the original Stax that I have with a transformer box it plugs in to ANY normal hi-fi amp that can output around 10 Watts-RMS. Your headphones dont have transformer box because the transformers are in the headphones. That means ANY type of amp or receiver amp just a normal amp dont need any flashy additions to it to make it work . The webs full of normal amps for sale but I would keep to an old good one if you cant affoard new .Its quality that counts.for good reproduction of music.You would need to get a converter for the plug on the end to connect to the output of a normal amp.    

 

[RAFA]

Quote:

No! Dont buy that it has a high voltage output  meant for Stax headphones 350V. Like the original Stax that I have with a transformer box it plugs in to ANY normal hi-fi amp that can output around 10 Watts-RMS. Your headphones dont have transformer box because the transformers are in the headphones. That means ANY type of amp or receiver amp just a normal amp dont need any flashy additions to it to make it work . The webs full of normal amps for sale but I would keep to an old good one if you cant affoard new .Its quality that counts.for good reproduction of music.You would need to get a converter for the plug on the end to connect to the output of a normal amp.    

What would you suggest then? I believe you probably have some amp on your mind.