The Naos Classic Overdrive is based on the Yamaha OD-10MII, an overdrive pedal originally released in 1987 as part of Yamaha’s “Sound Device Series” (SDS).
The OD-10MII is very similar to the Fuzztone, a DIY project designed by Dan Coggins (Lovetone/Dinosaural) for the magazine Electronics Today International in 1993 (available from Aion FX as the Atom Fuzz Drive). The main difference is in the clipping diode arrangement and the OD-10MII’s inclusion of an input buffer. Most of the component values are also different, so the two pedals sound nothing alike, but the similarities are hard to miss when looking at the two schematics side by side.
With this said, it’s unlikely that Dan referenced the OD-10MII when designing the Fuzztone, as the main building blocks of the circuit are fairly basic. But, it bears mentioning since the OD-10MII predated the Fuzztone by six years.
The Naos is a direct adaptation of the original Yamaha unit except that the flip-flop bypass has been replaced with standard true bypass.