[chrstnwarrior88]

Hello,  I am fairly new to headfi and the diy side of the house.  I have done a good amount of research and not found very much solid info on this subject.  So I thought I'd ask the experts. 
As of now I have a vintage sansui amp, and I am planning on buying a tube small tube amp fairly soon.  The headphones I'm using are k701s.  I dont have a great headphone amp to use with the 701s so I got a little creative.  I soldered 4 wires into a 3.5 female jack.  I soldered 2 to the ground then 1 left and 1 right.  on the amp I connected the wires to the left and right speaker terminals.  This works pretty well with the sansui, but I have read it might not be safe for the amp.  As I am getting a tube amp soon I was wandering if it is possible to do something similar.  I did read that I may need to add resistors to protect the amp.  Any way I was just wandering if anyone could give me a detailed explanation of exactly what I need to do, so I dont damage any of my equipment.  Any info would be appreciated.

 

[duncan1]

I suppose its a good way of blowing your eardrums. I take it the Sansui amp is a power amp designed for Hi-Fi speakers and is of a high wattage[RMS output] This is why dedicated headphone amps were designed.Yes you could blow the Headphones as well.
The suggestion for a series current limiting resistor is good. But you are brave . What if the volume was turned right up by mistake and you played some music? 
Whether the amp would blow would depend on what was left of your headphones and whether they constituted a short circuit across the amp output. If they blew open circuit it would probably be okay. 
 

 

[nikongod]

Grado used to make an adapter to hook headphones up to speaker amps. If you google it you can find schematics. 
 
I would be concerned that the noise levels will be too high, but the K701 have fairly low sensitivity so it should not be too terrible. 
 
DO NOT *just* hook the headphones up across the outputs on the tube amp unless you know that its safe. Since you don't know you **MUST** use an adapter with the tube speaker amp.
 
Accidentally bumping the volume knob on a power amp is not significantly different from doing the same on most headphone amps. 
Very few headphone amps are designed well enough that this sort of accident will not result in damage to ears or gears. 
 
 
I found the image:
 

 
You may rather use 10ohm resistors in place of the 20ohm ones, but to each his own. 

 

[chrstnwarrior88]

Thanks for the info. I did find that picture while doing some research. This is probably the way I am going to do it. I have the cable made already so I guess I just need to solder the resistors. The amp I am planning on using this on is solid state. (I do have a new musical paradise mp301 tube amp but I am not risking the output transformers with this mod). But just for curiosity's sake I will try it on a differant vintage ss amp that I have, just to see how the sound compares. Thanks again for helping me out.