The NPN version of the 707 is the same circuit, but with a standard negative-ground power supply scheme. The only real difference this makes is compatibility with daisy-chained power supplies that a PNP positive-ground circuit would short.
Sonically, theres a different color to the texture, something inexplicably clearer and more refined. Hence the white enclosure. The decay crumble is a little more chalky. The cleanup is a bit less gradual. Low gain tones are more delicate. Low end is a pinch more focused. These are my subjective takeaways of this transistor set, but you’ll still get the same roaring snarl and crumbling gate that you’d expect from the most aggressive MkIII variant out there.
Two black glass CV7112 transistors cascade into an Amperex 2N243, carefully selected and audited by ear. It is fair to say that I have most of the remaining stock of this device, and you won't find it anywhere else anytime soon. When I run through this bag, that will be it. For anyone.