Luxman L 505 U Integrated Amplifier

Depends on your associated gear as well. I had a Luxman 550 A-Mk2. Itx 30 watts x 2 (although more like 70 watts x 2) may not be sufficient for some speakers. I have a McIntosh 6300 now and it drives my B&Ws much better. Also worth mentioning is that contemporary Lux gear does not sound like Lux from the 70's and 80's. Although there is a resemblance if the vintage sound is what you are after you may be disappointed.

I've had the L-550 Mk2. You're right it probably is a step up from the L505u, but keep in mind that it is rated at only 20watts X 2 in pure class A. although, it is very much underated and probably puts out more like 65 watts X 2. nonetheless the L505u has more power (100watts x 2). Something to keep in mind when matching these amsp with speakers.