XLR to RCA adaptors

+1 @cleeds 

And just asking, why are you using balanced cables? 

If it is because you are running a long distance, say 10 feet plus, then using an adapter would negate most of the benefits a balanced connection would get you (mainly noise reduction).  In that case, then you might as well just switch over to a single ended (RCA) cables.

Adding a SUT so looking to use an existing RCA phono cable into a balanced Atmasphere pre that has a built-in phono. (Atmasphere is all balanced). 

I tried the Cardas a while back and eventually just had one end of the interconnects reterminated with RCA plugs.  If your system is significantly resolving and detail is important to you, then you will very likely notice a reduction in subtle inner detail and maybe more.   

rsf507 

... looking to use an existing RCA phono cable into a balanced Atmasphere pre that has a built-in phono

With that preamp you can use the RCA inputs and you'll enjoy all the benefits of a balanced connection.

Yup Ralph will tell you a MC cartridge with 0.25 mV or greater will work. Nope not even a 0.4 - 0.5 mV cartridge works with this phono. I've spoken to 3 other owners and all agree.