Do you need a big amp if you have sensitive speakers?

No. What you have just described only reinforces my belief speakers make the most difference, and as long as your amp can drive them adequately all is good. Pleased you're still enjoying the Planets.

No you don't need bigger amps. Just more of them

Amps HAVE changed over the years, at least decent ones have. You can NEVER have too much power, but the amp has to be good at low volumes too.

Steve C has some home made large single driver speakers of great sensitivity (all discussed on HFS and Audio talk). He loves his low powered valve amp projects he's made, and the home-made NVA derived amp is also well liked in this setup, but he did try a humungous Crown PA/venue amp (hundreds of Watts a side) and it didn't seem to disgrace itself at all at low domestic levels, which surprised me hugely in all honesty. All pictured and described on Audio talk threads going back six months or so.

The Krell KSA50 and 50S aren't really very powerful at all (90 - 100WPC class AB into 8 ohms but guaranteed half that power as Cass A as much as a complimentary circuit can be), but what DOES set them apart is the doubling of power into 4 and possibly 2 ohm loads and for that you need huge heat-sinking, maybe multiple output transistors and huge power supplies to deliver when needed. On paper at least, a Quad 606/707/909 family amp is actually more powerful - 130W+ per channel into 8 ohms, 225 W+ per channel into 4 ohms but maybe self-protected into much lower than this. Thirty years ago when the 606 came along, it was regarded as a seriously powerful amp, but not today really...


As an aside, maybe some of you with spare dosh should try one of the better pro amps to see if they can deliver for peanuts? Yamaha make some very well respected pro models costing well under a grand new. Jerry (jandll) the box swapper had and liked a crown XLI1500 for a while.

The thing is, many modern speakers are not that efficient, so many domestic amps of whatever quality are going to be pushed on peaks a bit. Most current Naims are better at low levels than they ever were in the 80's (I still find them bland though), but when you push them IT HURTS in my experience. Conversely, the little NVA A20 is only really around 125 - 20WPC at a push, but it soft clips so nicely you only realise it when it's gasping for breath.. Most domestic amps are somewhere in between in my experience... The baby T amps get recommended often and at very low volumes they're really good and clear, but the limits 8for me* are too low to be usable and the sound gets tinnier and tinnier the higher you go in volume - distortion grows to stupid levels too, so unusable for old headbangers like me...

Does any of the Sh#t above make any sense?

Well,  i'm on my way to a six pack. I still have all my Avondale amps as well and when all built I will have 12 monoblocs   

Four drivers in each of my speakers so I could possibly use 8 channels. The cost of speaker cable will probably break me though.

Agree.

People simply underestimate how hard it is to drive some designs of speaker properly, especially your typical 2 or 3 way tower speaker with its 4 ohm bass/mid. Current is more important than watts. I've heard plenty of systems that would benefit from  a better amp - and by better I mean better engineered not 'better' in terms of sound quality. IME the two go hand in hand anyway. People usually blame the speaker in such situations because on paper the amp should have 'enough watts'. 

The big difference of opinion on speakers like Yamaha NS1000s are entirely down to that ( and to a lesser extent the quality of the source. People overestimate how good their turntables are as well. Good speakers are less forgiving of mediocre vinyl set-ups but people blame the speakers).