Both of those reads were like an old memory. I didn't read much of anything but was reminded of everything way back then. Chrome tapes, cassette decks, what was the beginning for me of digital products coming on board, and oh yah, that Carver stuff, including the explanation of Magnetic Field Amplification! Man, that stuff was all hidden in my memory until I started rolling through the pages. I couldn't tell whether the drawing/schematic of the build it yourself SH was true to form as compared to the Carver, because as soon as somebody adds tape ins/outs, more switches stuff like that I tend to lose focus. It does appear however, that the same process was intended using phase reversal, a bit of delay, and cancellation, though I did not see cancellation in the drawing specifically. My bad though, like I said glancing at these circuits, I get lost pretty quick.
Jeffs has got it down for his DIY unit, and one of the best aspects about it is the remote control for the SH effect switched in or out. That is a big deal. Now if someone would just provide a 'volume' knob to the whole thing that lets you choose the amount of SH I would be crazy about it.