"How does the Spectron compare to the Sander Sound Amp"
These are very different designs. Spectron is class D and Sanders, as he explain his bias, is class B - may be A/AB but for 3 watts only
Spectron peak power 3400 watts, Sanders 2000 watts;
Duration: Spectron 500msec, Sanders: "momentarely";
Peak voltage, Spectron 120v, Sanders - 90 volts .
Weakness in design: Sanders uses usual negative feedback which produces odd orders harmonics and Spectron's negative feedback is 10 times faster - so practically no odd harmonics, particularly at the peaks when sound can reach ear piercing levels
Sound - I listen to Sanders but it could be not in optimal system so I will not comments here
Al; The Best
Rafael