Prevent xxd from adding newline to the output

On unix if I do

printf "aY.S'Hk([;jYJ}8eJ5)Wsd58/x}s]Pne3V-6:t@" | xxd -p -c 256

I get

61592e5327486b285b3b6a594a7d38654a352957736435382f787d735d50 
6e6533562d363a7440

However on mac os (which is what I want on linux as well) I get

61592e5327486b285b3b6a594a7d38654a352957736435382f787d735d506e6533562d363a7440

I couldn't find any way to prevent xxd from adding a line break to hex output. I have tried sed to remove the line break but it doesn't work. I can't install tr on my unix machine. Is there any way I can create a hex output from my string that doesn't have any line break or whitespace or is there a way to configure xxd on linux to not add any whitespace? Note, I have tried pretty much all the options of xxd with no luck