Searching “Nirvana Unplugged” yields several types of content:
Official commercial releases (the 1994 album, 2007 DVD, 2013 “Live and Loud” companion) are not on archive.org due to copyright, but fan-made, unaltered broadcast captures and rehearsals often are. nirvana unplugged archive.org
Use the search bar at archive.org with the following strings (include quotes for exact matches): Official commercial releases (the 1994 album, 2007 DVD,
Stfw.Ru"Nirvana Unplugged" soundboard
"Nirvana MTV Unplugged 1993" audience
"Nirvana - Sony Studios 1993"
Filter by Item Type → Audio or Movies. Look for ETree (lossless) or MP3 ZIP packages. Use the search bar at archive
Pro tip: Many uploads are part of the Live Music Archive section, which is legal for trade-authorized bands. For Nirvana, the band's estate has historically tolerated non-commercial trading of unreleased recordings, but note that officially released material may be removed upon DMCA request.
On the official release, the gaps between songs are shortened. You miss the context. On the Archive.org bootlegs (sourced from the original soundboard or audience DAT tapes), you hear the full tension of the room. You hear Kurt joking about his broken guitar ("I broke a string... shit"), complaining about the monitor mix, and awkwardly introducing the Meat Puppets. You hear the 15 seconds of dead air before "Pennyroyal Tea" where Cobain sighs heavily—a moment that hits harder now than it did in 1993.