Hi Saint,
I want to do the same thing, but I have a recently repaired and tuned with new soundsmith MMC cartridge Beogram 5000 connected to the Beomaster 5000. (I also looked into the AT, but am hoping I can find a purer way to do this. I want my digital recording to be as hi fidelity as possible, even picking up the pops and scratches that might be on my records.)
I could:
1. Get a pre-amp connected to RCA cables from the Beogram and an analog to digital converter as you suggest.
2. Connect the Beogram to the Beomaster with the 7-pin DIN and then use RCA cables to the Pre Amp out from the Beomaster and connect an analog to digital converter. The Beomaster would be the pre-amp. I might even be able to program a mix of record, cd, and tape to be output to a single file . . .
I think #2 would get the purest Beo-sound, but might introduce issues or not be as good as #1.
What do you think?
(I hope to take the digital files with me to listen on the road, but I know the sound will not be the same. Worth a try.)