Serious speaking though , the source material’s signal level should always as high as possible (such as, your TV’s audio line out, CD player, DVD player, VCR...etc), prior to rest of the signal processing equipments, and the level control of the power-amplifier as low as practical for best signal to noise ratio. Gain boosting at later equipments is the last resort and should be used moderately.

For me, CD always has an excellent, strong signal level (easily hit 2 Vrms with SN ratio of 115 db, yet without any gain boosting). And that’s where DVD disk should improve.