Toshiba 1s1588 Diodes

[Mark Hammer]

For many years Elektor magazine used the nomenclature TUP, TUN, DUG, DUS in their construction articles.

TUP - transistor universal PNP
TUN - transistor universal NPN
DUG - diode universal germanium
DUS - diode universal silicon

The idea was that there are a whole variety of projects where the particualrs of the semiconductor really don't matter all that much.

[zeeman]

I guess the 1s1588 was chosen, because this was ubiquitous in the place/time  the circuit was designed, no other reason.

Without a doubt, this is the correct answer - therefore it is wrong. (see below)

Will somebody PLEASE tell me what is the critical difference between them?

You clearly missed the "MOJO" spec in the datasheet. I am sure it is there.

zeeman

[jasperoosthoek]

  The S is more curved than the N giving you smoother clipping and less fizzy distortion. 2N-type trannies usually give double the fizz.