Correct! The SDS converts wall AC into DC, then synthesizes AC, at whatever(user adjustable) frequency it takes to achieve 33 1/3 or 45 rpm. It also lowers the voltage, after platter start-up, to reduce motor noise. I like not having to change the belt, to go from 33 1/3 to 45 rpm. That now just takes the push of a button.
SDS or phono stage
I have a VPI Scoutmaster with Soundsmith Zephyr Mk II cartridge, jmw memorial arm, a stainless steel vpi record clamp, playing through a Musial Fidelity KW500 integrated amp with on board phono stage. Sounds quite good, but my question is this: would I be better off at this point adding an SDS or an outboard phono stage? Or both? In what order? Thanks!