External headphone amp

Jakebake,

If your intent is to connect your tube amp to headphones, instead of speakers, read this post:
http://www.head-fi.org/forum/thread/527408/hd600-speaker-amp-is-it-possible#post_7117359
My post (#10) in the thread lays out the parts needed and what needs to be done. Soldering skills are required, but it's not hard.

There is no need to alter your headphone cable/jack, as, I believe, some in that thread suggest. Instead make a new adapter cable which connects:

- a short wire from the amp's left positive (+) speaker output to one end of a 100 ohm resistor; another short wire from the opposite lead of the resistor to the 1/4" female phone plug's "tip" (+ left channel);

- a short wire from the amp's right positive (+) speaker output to one end of a 100 ohm resistor; another short wire from the opposite lead of the resistor to the 1/4" female phone plug's "ring" (+ right channel) connection

- separate wires from each of the left & right negative (-) speaker outputs to the 1/4" female phone plug's "sleeve" (common ground) connection. The ends of both wires are soldered to the "sleeve" (- common ground) on the 1/4" female phone plug.

If you want to get fancy, and assuming your amp has 5 way binding posts, you can also purchase some male banana jacks. Here are some links (some need soldering):

http://www.monoprice.com/products/product.asp?c_id=104&cp_id=10401&cs_id=1040115&p_id=2943&seq=1&format=2

http://www.alibaba.com/product-free/238532697/4mm_Banana_Plugs_Solder_type_Pair.html

http://www.parts-express.com/1/1/1289-gold-plated-crimp-banana-plug-16-pcs.html

Solder or screw these jacks to the ends of the 4 wires which connect to your +/- left/right amplifier connections. This will make it very easy to remove the adapter and reconnect your speakers. As you're soldering you might also consider heat shrink tubing to add the final "professional" touch. (You will need a heat gun or hair dryer to shrink the tubing).

NOTE: resistors are not directional, so it does not matter which way you orient them in this project.
Edited by Rizlaw - 12/19/10 at 9:03am