I wish to make the following design as a DIY project.
At higher gain settings where the input impedance drops to about 9kΩ, and when driving multiple inputs in parallel, the MP3 player sees an impedance 9kΩ/N where N is the number of parallel amps.
I'd start to frown when the parallel impedance drops below 1kΩ (9 in parallel) and I'd start to worry when it drops below 100Ω as most MP3 players are designed to drive 32Ω headphones.
But practically, how do I determine the limitation factor?
Can I drive a dozen? Anyone with experience?
Question 2:
the datasheet speaks of a technique called "power supply pumping". i tried my best friend Google but found no luck. Could someone please explain how it relates to a project like this? I would so much appreciate a good explanation.
Thank you very much.
