30 to 50 watts seems to be all I desire

@audiodwebe 

Caveat:  Listening to mainly Jazz at volumes less than 85db, normally.

This explans in large part your outcome and the fact that you listen in a modest size room. Quality of your amplifier has more bearing than the quantity of watts. Your scenario makes perfect sense to me.

As others have pointed out, the limited volume control usage range is a reflection of excess gain in an audio system and is not due to too much amplifier power. The higher the sensitivity of your speakers or amplifiers the less preamplifier gain is needed. If your digital source or phono cartridge is high voltage output,  the less gain you require. 

Charles 

I’m down from 255wpc with a Hafler DH-500 to 17 wpc from Dyna/VTA 70 with KT66 in triode mode. Plenty loud for me with average efficiency speakers in a 24x24 ft room, and sounds amazing.

The AVERAGE watts even on inefficient speakers playing loud is only in the low single digits. Even an avreage twenty watts would either drive you out of the room or else make youd deaf. Power is used for very, very short term transients which can be 20 to 30 dB(20 Db is a multiplier of 100). These transients are very short and good amps recover from the overload very quickly. But even good amps clip these transients and weaken the fidelity. If you want the best sound as my old friend George Bischoff(Melos amps, 200 and 400 watts triode) said - a good big un will beat a good little un every time.

I have three amps, the “biggest” being rated at 6.5 watts per channel (parallel single-ended 2a3).  I bought a pushpull 349 amp from an Italian builder.  I had the amp for a couple of years and had no idea of its output capability.  When He came here for a visit, I asked him, out of curiosity, what was the output capability of the amp.  I could see that he was annoyed by such an irrelevant question; he thought for a brief moment and threw out a number—around 5.5 watts.

Listening to mainly Jazz at volumes less than 85db, normally.

I used to listen close to 90dB when I was younger(20+ to early 30s) with peaks hitting 100dB. Now a lot older, my average listening volume is 65dB. At these levels, any amp would do it.

I occasionally listen at 70 to 75dB only for a short period of say 10 to 15 minutes.

The average SPLs I recorded with the Radioshack meter (~65dB).