Denon DL 103 vs DL 103R

Grimace
All the above posters offfer sound advice regarding the Denons.You being like many see the relatively cheap entry price of the 103's and think that you'll get great performance just setting it up, "WRONG" these carts need the same care and attention to detail that >$ 1k carts do ie. solid phonostage, and arm that can control it's otherwise low compliant nature and not to mention a step up that doesn't rob it of it's musicality(bandwidth),and adequate gain.
Mrjstark said it best there is a lot to learn about these carts, and it's all here,you just have to reach out and find it. I have a plain 103 and LOVE it I am still working to optimze it but it is a GREAT cart out the box.Many have found the ReGa 300 and variants to be adequate if not suitable matches for these carts.I use a Origin Live silver with very good results,I have since nuded the cartridge and placed it in a wood body,to tame the resonant nature of the plastic body.
one last point, to oversimplify the differences of the two.
I've heard it described as the 103 being more"organic" while the "R" still retaining the Denon sound err's a little on the "HI-Fi" side of things.
you are on the right track with the choices you've made thus far, but there is more work to be done

just my two pennies
braab

So, set me straight here. Would using this cartridge require the use of both a phone stage and step-up transformer? I'm still not entirely sure what the transformer actually does.

I've also read that these cartridges can have issues with metal platers. Would that be an issue with the Thorens platter?

I had asked on a previous thread what a step-up does, and the response was that it boosts the signal to make it compatible with a MM phone stage. Couldn't I accomplish the same thing by using the cartridge with an external stage into a line input?

Yes, if the stage is itself suitable for the Denon's low output and loading.

Grimace,

Some phono stages aren't designed to provide sufficient gain for a moving coil (MC) cartridge (or they may be able provide sufficient gain, but it pushes the phono stage to the uppper end of its limits). A step-up transformer (SUT) can help in this situation.

For example, I used to own a Wright WPP-100c phono stage and a Shelter 501 mk II cartridge (MC). While technically I could get enough gain from the phono stage alone, the Wright isn't designed to work with low-output MC cartridges, and IMHO it didn't sound as good as when I used a step-up transformer along with the Wright WPP-100c phono stage. If I was using a high-output MC cartridge or a MM cartridge, a SUT may not be necessary.

Now I use an Ayre P-5xe with a Denon 103R cartridge. The Ayre phono stage is designed to work with low-output MC cartridges, so a SUT is not necessary.

This is an oversimplification, but you'll get the picture.