Headphones from speaker jack?

[dynaman]

I'm interested in building a speaker dummy load with an adjustable lineout/headphone jack. An attenuator with adjustable headphone jack would be even cooler, but I don't mind starting simple. Anybody point me to some schems??

[iknowjohnny]

You should be able to use any schematic with a speaker tapped DI out (many do) and just use a stereo jack instead of a normal 2 conductor jack and wire the DI output to tip and sleeve. Then test it and if it need more or less volume adjust resistors to taste or add a pot for a adjustable level like you mentioned. Then just add a load to the speaker jack. This will give you the output's contribution too so it will sound worlds better.

[dynaman]

Hmm, can you point out some specific examples? I can't seem to find the appropriate schems....

[MasterDisaster]

Some numbers and links to get you started.

IEC standard might be a good starting point and it stipulates 5V, 120R.
A voltage divider circuit should be sufficient for this purpose so you first need to calculate the output power of your amp and to what load you are connecting it to.
100W into a 4R load will give you 20V.

This link contains a calculator and just type in three of the values and the fourth will be calculated for you.
http://www.raltron.com/cust/tools/voltage_divider.asp
In this case R1=360R
R2 is preferably a pot so you can adjust the volume.

Mike