Hi Steve,
Fully agree with Tweak1, you should better upgrade the preamp than your V70. The LS2B is a good preamp (i used to have a LS2 and LS2BMKII) but audio research did a lot of improvement since the LS2. I would recommend you the LS5MKII if you like natural sounding or the LS25MKII if you prefer something more open, and more dynamic. The budget for those 2 preamp are maybe higher than $1600, but i'm not sure the LS15 or LS16 can be much better than the LS2B (i've just compare my parent's wife LS15 vs my LS25MKII, then they are not on the same league). I don't know the SP16 but you will have issue with the XLR connection of the V70.
Fully agree with Tweak1, you should better upgrade the preamp than your V70. The LS2B is a good preamp (i used to have a LS2 and LS2BMKII) but audio research did a lot of improvement since the LS2. I would recommend you the LS5MKII if you like natural sounding or the LS25MKII if you prefer something more open, and more dynamic. The budget for those 2 preamp are maybe higher than $1600, but i'm not sure the LS15 or LS16 can be much better than the LS2B (i've just compare my parent's wife LS15 vs my LS25MKII, then they are not on the same league). I don't know the SP16 but you will have issue with the XLR connection of the V70.