Originally Posted by robrob
Would this type of two resistor network be better than the one in my spreadsheet? Is this the consensus "best headphone network" or is the three resistor network better if optimized to your amp and headphones?
Hi Roberto, (makes you sound like a ladies man, yes?)
My opinion.................use the two resistor network.
I like the idea of resistor #3 in your diagram.
#2 gives you the attentuation you may need, #3 adds some damping to the system i.e. makes the amp output impedance appear to be low (in some respects).
Personally, I'm not a big fan of using an old receiver with a 120 Ohm (or 220 Ohm or whatever) between the headphones and the power amp, it's just not very versatile, with many headphones the interaction between the series resistor and the headphones can create frequency response aberations.
A properly chosen value for Resistor #3 greatly reduces that effect.
You guys already do all this when you chose R2 = 12 Ohms, R3 = 4 Ohms (for example)!
I may have "a bit of bias".......
I've worked as a power Engineer for about 25 years, + I spent a year designing Analog Signal processing gear.
Edited by Chris J - 12/1/13 at 8:14am