This is my overview and review of the IK Multimedia iRig Pre 2, the updated version of their iRig Pre preamplifier. It provides a single mono balanced XLR input to an unbalanced 3.5mm TRRS (and TRS) jack for connecting balanced professional microphones to devices such as older iPhones & iPads, camcorders, DSLRs and mirrorless cameras. Newer iPhones/iPads without a headphone jack need the Apple headphone to Lightning connector.
At time of uploading, I cannot find the product on Amazon, only the original version. But see www.ikmultimedia.com/products/irigpre2/ in the meantime.