[Detex]

Hi, I am new to the forum but I had a questions about a 300b set-up. For the most part I have used my amp with speakers but would like to know about hooking up headphones off the speaker thermals. I would assume that with the 300b and inherent low power output this would not be an issue but I am also afraid to blow-up the amp due to some thing I am not considering. Most likely I would try it with a pair of Grado 90's. Please let me know if you have any input on the matter. I was planning to just build a headphone jack to splice onto the terminals.
 
 
 
Thank you in advance!!
 
 
Detex

 

[JB197]

If your amp can drive speakers it can drive headphones, but it's likely to have far too much gain (amplification) and you will only be able to use a tiny fraction of the volume control.
 
You can attenuate the output with resistors but you normally loose sound quality.
You can attenuate the input with resistors but you normally loose signal-to-noise ratio.
 
Perhaps it might be best for you to meander over to the DIY section, post your schematic and ask for advice.
 
 
A couple of points:
If your amp has an anode line transformer (i.e. series feed output) then don't operate it with no load attached.
Some jack sockets have inbuilt switch contacts to disconnect the speakers when a jack plug is inserted... the switch contacts in such a socket are normally quite poor and can be the weak spot of the system.

 

[Uncle Erik]

What JB197 said is right.

Either that or you could just pick up an AKG K-1000 and run it directly off the speaker taps! It might be an expensive solution, but a highly enjoyable one.

 

[nikongod]

I would advise putting a 12ohm power resistor (or 24ohms if you have a 16ohm tap on your amp) in parallel with the headphones to dampen transformer ringing, and generally protect the amp. After this you can unplug headphones reasonably safely.
 
After that, as long as the amp dosnt hummmmm too badly rock out!

 

[krmathis]

Definitely give the AKG K1000 a try.
Imo a 300B amplifier really make them shine - like few else.

 

[Detex]

Thanks guys, the AKG K1000 sound intriguing. I have a set of B&W P5s and I love them but am always open to new ideas. I am going to give it a try with what I have and see how it goes.
 
 
Thanks!!

 

[Audiogalore]

Try the Dared VP300B at 9 watts per channel works very well with K1000. Certainly brings out the highs like liquid.