Two things, source and preamp. I recently replaced a laser in an older Rega Apollo CD Player and that $25 part just made the CDP sound so much better in clarity/resolution. It has me thinking that over time, the laser gets worn out. Clarity and resoltion were a hugh improvement. I will be experimenting with older CDPs to see if this is consistant. That being said, the preamp also has a big impact on clarity/resolution. I build direct heated triode, transfomer coupled preamps and no conventional preamp can match what this does basically because there are no caps in the signal path.
Happy Listening.
Happy Listening.