stupid question about sources, amps, and loudness

Okay, so I really should know this, but I don't, so your help is most appreciated.

My speakers are a fairly tough load to drive 86db efficient, 6 Ohms nominal.

That suggests that I need reasonably powerful amplifier(s). Currently I use solid state amps rated at 100 WPC.

The amps are Kharma MP150s. They drive the speakers quite loud, although they do start to "flatten out" at 95 db (which is much louder than I typically listen, even when I've turned it up).

I have some issues with not having enough range of volume control either with a pre-amp or with a CPD with a volume control -- that is to say, if I turn the volume control much past 10 or 11 it is too loud.

I know that I can use attenuators to fix the volume control problem, but that they also can have sonic consequences.

Here's the question: less powerful amps are NOT the answer right? It's input sensitivity. Right?

So, if for example, I am thinking of trying tube amps, I still need to be mindful of the difficult to drive speakers and thus need to get some pretty beefy tube amps (i.e., 100 WPC+). Because less powerful tube amps won't have enough current to drive the speakers effectively.

BUT: I would want amps with a lower input sensitivity?

Do I have this right?

Thanks for clearing the cobwebs for me.

Sounds like a gain issue. What is the gain rating on your current amp? I have several different amps with different gains each, having nothing to do with power rating. If amp X has more gain than amp Y then the speakers playing from amp X at a volume setting at 10 o'clock on the same preamp with be louder.

Seems like the common component is the CD player, whether direct or through the preamp. Maybe it is your CD player that has more gain and is causing the issue? I have two CD players with volume control. One I can turn up all the way and have tolerably loud music. The other CDP gets too loud at about 60% of full volume. Note - this is when they are being run variable output direct to the amp.
Ckoffend, thanks. I can't find a gain spec on the amps. They do have an input sensitivity of 1.2 V.

I actually tried the amps with a different CDP. Same issue. I can attenuate the output of the pre-amp with internal jumpers by 20 db. But the sound quality is reduced.

So there's gain, current, and input sensitivity. How can you ever know what components are going to work.
The gain is probably the better number to pay attention to because it is not relative the the power rating of the amp.

If only the power rating and the sensitivity is given, gain in dB is related to the power rating (at 8 Ohms) and the sensitivity by

gain = 20*log10(sqrt(power*8)/sensitivity)