Very little. In fact it's the last thing you want to look at. If you have tried different setups and had done everything you can within your knowledge, and still want that last little bit of change, an IC or LOD would be your next step. Persoanlly I haven't experienced anything worth noting when changing from a stock IC to a well built DIY IC (I bought one from a forumer here. Had Canare plugs and high quality cables. Quite decent for RM90+). There are ICs that can cost upwards of RM600, haven't tried those. But from my experience, it's the very last thing you would pick up, and you should invest in the best source and amp first.

But investing in a decent quality IC wouldn't hurt your budget much. They'll last longer and look better (but most of them are bulky).

I wish representatives of Jaben Malaysia can come here at PC fairs.

This post has been edited by tunertoobe: Dec 7 2012, 06:36 PM

And why am I not informed of such a seller?
Just kidding. Does he have an actual shop or does he do business at home?
So why not he represent Jaben at PC fairs? Well I haven't been to the local PC fairs in a while so I don't know if it has already been done. Would be a good idea to introduce budget stuff here.

Drawing more current is easy. Generating enough voltage is a bigger problem.

You can search for functions of portable amps (you can type keywords that are something like that in google).
I'm not an electrical expert, I just know enough to make me able to understand things.

Basically it's easier for players to dump as much current as the chemical reaction in their batteries allow them to, but when high impedance headphones that need higher voltage to do the same amount of work (loudness) is plugged in, the player alone can't do anything as the battery is limited to a certain voltage.