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

gain and input sensitivity ...man, how about my conrad johnson preamp:

Gain:

Phono stage 47dB

Line Stage 31dB

is is sometimes too loud at 9 o clock. i use inline attenuators on amplifiers that dont have a volume knob. man this thing has a lot of gain.

Heard back from Stanton re: the Hiraga specs

Input sensitivity is .5v

30db of gain - not 26 as I had thought.

That would explain the volume increase!

The Cary SLP-30 I am driving it with has variable gain, so I gave some wiggle room to play w that adjustment.

That would explain the volume increase!

haha... when seemingly weird stuff happens there is ALWAYS an explanation, it is just that sometimes it takes us a while to figure it out!

Very much appreciate the input/information!

This surprise, sent me down a rabbit hole of “research”.

Now, I have more questions than I had prior to this observation :)

mwood:

I'm assuming your preamp has a resistive volume control. If that's the case. the "higher" the volume setting the less resistance. That's preferable for better sound. It's been the case for decades that many home audio preamps have much more gain than they need or is desirable. If your volume settings run only up to, say halfway before maxing out, your preamp has too much gain. Your tube preamp 3-5 db gain was actually better suited to your system than the 9db gain preamp. 

Excess gain preamps that result in volume settings between 1-5 have trained users to expect that. When a preamp with a resistive attenuator is used mostly between 5-9 (on a scale of 10) that's ideal, but seems wrong due to previous experience with excessive gain preamps. The output voltage of the preamp should drive the amplifier to maximum power output at just about the full volume setting. That's when the attenuator is resisting the least and converting as little as possible of the voltage gain to heat.