While I'm sure the Allnic unit has many tubes and nickel-core transformers enclosed in a shiny fascia (I believe Brinkman has a similar device), this is by no means a guarantor of accurate motor control - personally, I'd prefer a substantial number of integrated circuits to be at the heart of my motor controller. Synthesis and control of discrete sine waves for motor control applications is a delicate task requiring a high degree of repeatable accuracy best performed digitally with an analog amplification stage. A phase shift cap is a crude attempt at best...
-Richard
-Richard