Yes they are. The original NBC broadcasts were released on DVD in 2004.
I know you meant the effects sequences, but to be accurate, the original NBC broadcast versions have never been released on DVD. The sound mix has been screwed with since they were put out in 1999. Music changes and new sound effects are all over the prints and are still on the Blu-Ray release. The closest we got to original NBC broadcasts were the VHS/Laserdisc releases. But even those had alterations, such as the opening and closing credits in the first part of the first season and the syndicated versions of the Next Week previews.
Oso Blanco wrote:
I finally found what I was looking for ... I actually started the thread myself back then, and one of the answers I got was this (emphasis mine):
Yes, you can choose to only watch the episodes with the original effects. You can also choose to listen to the mono track with (for the most part) is about the same as the original sound mix as the originals.
However, there are a couple of episodes which incorrectly have the new opening credits, even when you choose to watch the original version. The rest of the episode is fine, just the credits got screwed with.
You can also listen to the original sound mix over the new effects, so you never have to listen to that re-recording ever, even if you're in the mood for the new footage.
Can anyone confirm or deny that thing about the opening credits?
Ooo, ooo, that was me! And yes, I can confirm it exists, but I'm not home to pin down the episode(s). The first season was where I noticed it, possibly Balance of Terror.
EDIT: I checked the Blu-Ray of Balance of Terror last night and in both the hi-fi and mono tracks in the original effects versions, the 2006 newly orchestrated theme is there. The old visuals are intact, but the music is the newer version. I didn't really have time to go through to find other episodes (I think there's at least one more), but I can confirm Balance of Terror.
The DVDs also restored the "created by Gene Roddenberry" credit to the open theme of The Man Trap and Charlie X, as seen originally in 1966. Gene's credits at the end of both episodes were amended to simply "producer" on those prints. The Blu-Ray episodes do not have those restorations. Another reason I prefer and will retain my DVDs of the series (which really look great).