i've recently replaced the panasonic portable headphone-jack with the new-bought RA1 to drive the RS-1. The details are much clearer and much more than the portable's jack. But the sound now seems much thinner and lacks bass boost comparing to the jack. i also tied another pioneer dvd-player as...

i have a old model(SL-S350 of 1996) of a panasonic portable cd player. i want to choose a sennheiser(or other models) headphone to upgrade the sound quality. but i wonder if my pana can drive the new headphone? anyone could you help??