The surprise, not only did the Elekit drive the Sabrinas very well (improved clarity and tonality), but at the same volume with the same input level as the Modwright! Using a passive preamp, when I set the volume knob on the preamp to the same point for both the Modwright and the Elekit it results in essentially the same volume from the speakers.
@gareents There is more to this than just power. The reason the SET seems to keep up with the more powerful Modwright is due to the distortion it makes. As you push it harder, higher ordered harmonics show up (the amp lacks feedback so this is normal) which convince your ear that the sound is louder than it really is. A sound level pressure meter (which is available as an app for most phones) will reveal the truth of the matter.
Put another way, the mark of a good system is that it doesn't sound loud, even when it is. This is because it makes less of the artifacts that the ear uses to sense sound pressure, so sounds more relaxed.