I backed up an audio CD that had varying pre-gap lengths with my PX-716A (TLA 0304). I first tried PlexTools Pro 2.20, and it made the .pxi file, and as I watched it burn, I saw it reported it was burning track by track. Now track 13 was not a surprise since it was data (enhanced CD), however I was surprised to see that the first 12 tracks (all audio) were burning track by track.
This made me suspect that PlexTools Pro is burning in track at once (TAO) mode instead of disc at once (DAO) mode.
I decided to make an Alcohol 120% image (.mdf/.mds) of the CD and burn that. I used the AudioCD+ profile that read in the CD in RAW DAO mode, and when I wrote I burned using the same profile. Well, from looking at the burning surface I could see a big difference - gone were the visible gaps between tracks! with the plextools produced CD, I could see small, unburned gaps between the audio tracks, and a larger gap preceding the data track. This is supposedly proof that it was burned in TAO mode...
So, I fired up RecordNow Max to examine the disc (it has a convenient way to view pre-gaps in it's disc explorer). Well the pre-gaps were all zero now, except for the one preceding the data track, which was 2 seconds, prior to session 2.
I re-burned the Alcohol Image and this time modified the AudioCD+ profile by telling it to "rectify subchannel data." The result was the same - zero pre-gap between tracks.
I even burned a third disc with Alcohol, this time using AudioCD profile, and burned in DAO/SAO mode (versus RAW DAO), and the result was the same (no pre-gap between audio tracks), except this time I can see a visible gap prior to the data track (session 2)!
SO, how would one use Alcohol 120% to maintain an EXACT COPY of the disc, including pre-gaps? Or, is the PX-716A incapable of burning this disc in DAO (RAW or regular) while maintining pre-gaps? Is that why PlexTools chose to burn in TAO mode?
If you are wondering why I care, I'm a stickler for a 1:1 copy and some things (like the old CDDB - now gracenote) supposedly used the pre-gap information to help identify an audio CD title.