can I plug in to the balanced end at the amp and the RCA end at the pre...
Bullot (Answers)
Yes, you can do that. You will need RCA>XLR adapters at the amp end if you're using RCA interconnects, or you will need XLR>RCA adapters at the preamp end if you are using XLR interconnects.
...or should I get adaptors for both ends?No.
You have the choice of using RCA interconnects with an RCA>XLR adapter at the amp end, or the choice of using XLR interconnects with XLR>RCA adapters at the preamp end. There will be no difference, IMO, since you will not be running balanced considering the Joule is not a balanced source.
Or, you can use RCA interconnects, and run single ended from the Joule and single ended into the Levinson. My hunch is this will sound best. Adapters are inexpensive, so you can experiment with both options.
The decision of which amplifier input to use, and which preamp output impedance to select is going to have the largest impact on the sound you get, due to the potential impedance matches (or mismatches).
The impedance match selecting the Joule's 350 ohm output impedance should match very well with the 33H's single ended 50k ohm input impedance.
If you use the 33H's balanced inputs, you might want to select the Joule's 1200 ohm output impedance considering the 33H's 100k ohm balanced input impedance.
You have a lot of options, and only experimentation will tell you which configuration you will prefer.
Nice combo. Have fun.