No Vocals from Grateful Dead RSD LP


Hello -- this problem has me perplexed. I purchased the Grateful Dead LP on RSD and when I played it, I didn't get any vocal output. So I emailed the distributor (Rhino), which sent me another copy. I put it on last night and ... no vocals! All my other vinyl plays perfectly. My system is a Thorens 165 turntable w/Grado Sonata cartridge, Dynaco ST70 power amp, Dynaco PAS 2 preamp, Budgie phono preamp, and Dahlquist D-10 speakers. I plan on going to a record store here and they have turntables and I hope they will allow me to play the album to see if I get any vocals from another system. However, any idea/troubleshooting to find out why I"m having this the problem with this LP? Thanks!.
theeditor
Now if you can just get rid of the endless guitar noodling you might end up with a decent record! 
I went to a record store and played the album on its system and the vocals were clear. I changed the phono cartridge on my system to see if that was the problem and I heard vocals for one song, then nothing but instrumental...
Finally figured it out -- I changed from a Grado Sonata to my backup, a Sumiko Pearl. I fooled around with the gains on the Budgie preamp, and what do you know? I have vocals! It never occurred to me to change the gains on the Sonata. Thanks everyone!