Need to add a Line Out

[Joe6v6]

So I need to add a line out to an amp I built. The guy that uses it is hell bent on having an on board line out instead of using a direct out box between the output and the speaker. Ive looked around & I see all sorts of schematics & recommendations for resistor values, but mostly they are for lower wattage amps. This amp uses 4 6l6's so in the 80 watt neighborhood. I did it like the attached pdf shows, I used 470r and 2.2k and it works but seems a little hot, all I can do to test it right now is plug it into another amp. What resistor should I change to drop the output or could I put a pot somewhere & make it variable?  Thanks : Joe

[shooter]

you can try the values here as a start, you don't need the tranny.

[2deaf]

Increase the 2.2K to 4.7K or reduce the 470r to 270r.  Does the OT have more than one output impedance?

For a variable line out, leave the 2.2K and replace the 470r with a 500 Ohm linear pot.  Connect the wiper to the line out jack.

[Joe6v6]

Increase the 2.2K to 4.7K or reduce the 470r to 270r.  Does the OT have more than one output impedance?For a variable line out, leave the 2.2K and replace the 470r with a 500 Ohm linear pot.  Connect the wiper to the line out jack.

Thanks - This is what I was wanting to know - Yes the OT has 4-8-16 on a rotary switch. 
Since its in the ballpark now I think I will try a 500 Ohm pot with a 100r resistor so the value will not go below that. 

[PRR]

> seems a little hot, all I can do to test it right now is plug it into another amp

Instrument Input is *hotter* than Line Input.

So you may be done already. You really need to try it on a standard PA console the way it would be trimmed for performance.

[Joe6v6]

Instrument Input is *hotter* than Line Input. So you may be done already. You really need to try it on a standard PA console the way it would be trimmed for performance.

Good point - I guess I will let him try it as is & tweak it from there.   .     Thanks

[2deaf]

Yes the OT has 4-8-16 on a rotary switch. 

Which output tap you connect the line out to makes a difference with how much voltage the line out has.  As an example with the amp putting out 80 Watts_rms, the 4r tap has 25.3V_p, the 8r tap has 35.8V_p, and the 16r tap has 50.6V_p.  So you can also tweak the line out by keeping the resistors the same and moving to a different tap.