My 30 Watt class A is louder than my 100 Watt Class AB?

I had a situation that was opposite of the "too much gain" scenario. I tried to use a Schiit Saga preamp (unity gain) with their Aegir power amp which is on the low side of amp gain. I had to turn the volume up to near max on most recordings to get an average listening level. That meant when I tried to play recordings with lower-than-average volume levels I was unable to reach my desired volume even though the amp had more than adequate power. I solved the problem by selling the Saga and switching to their Lyr 3 which has switchable gain (+3.5 dB or 17.5 dB).

@russ69 -- I know the Saga has no gain (that's what "unity gain" means.) And I was using a DAC with the typical 2 volt output, so nothing amiss there. While most of the time I got the desired playback volume, the problem was when the recording itself was recorded at lower than normal volume. Certainly not a problem with most pop/rock material, but there are some recordings out there where this can be an issue.  Its not an issue limited to certain turntables/phono preamps.