Arion MMP-1 Metal Plus

Here's something cool. The design reminds me of something else a lot - i think some of you may want to take the diodes on a switch with red 3mm LEDs :)
Original unit has NEC C157C metal can IC in it, but NEC's own cross reference guide says that this particular IC has been obsolete since around 1975 and it's exactly the same IC as LM301AN, a PDIP-8 chip that is still quite a standard. Original output buffer is marked as 536 in the schematic, so i guess that would be 2SC536 or 2SC5368. Nevertheless, it's still just an output buffer, so i used your average everyday pinout. This way you could use something like 2N3904 or 2N5088 in it's place.

Very little info available. Other than one near mint unit was apparently sold for $250 couple of years ago...

Now verified. I swapped 68p for 470p to tame oscillation, and there were couple slight issues (one cap was typoed to 330n instead of 33n, tone was in reverse, pot tapers felt wrong as those are not stated in the schematic). All those are now fixed. This is in fact very nice Rat alternative. I also used 1N4007s for clippers. Recommended build.