[Formerly YB-2]

Originally Posted by miner

Is a headphone amp required for LCD-3s if my integrated amp and my preamp have jacks?

Like most anything else we listen to, it depends...................
Depends on how your preamp/integrated amp handles headphones. Some feed 'full power' to the earphone jacks and some use a voltage divider and limit the voltage/current available and some use other designs. My suggestion would be to do some critical listening, as should be easy to A/B (plug into the preamp then plug into the integrated amp). Also, if/when you decide to purchase a headphone amp, try to get one to audition and A/B against your current preferred source (preamp or integrated amp).