laptop headphone socket out to amps

I'm very new to computer audio and have a minimalist system with a passive preamp for volume control of vinyl and cdp, but was cinsidering a direct connection for digital. Has anybody connected the headphone socket of a laptop via a Y-cable directly to their amps, using the laptop's D/A converter and volume control? Specifically, is there an advantage in sound quality when using the computer's volume control and avioding the passive preamp and additional interconnect? Also, would CDs ripped to lossless with this configuration sound better than my Rega CDp? Thanks.