I was told that I needed an impedance transformer in a music store. In fact a sales person tried to use a regular XLR to 1/4 inch cable with Beta 58a and plug into a mixer mono channel without sucess. He then told me to buy an XLR cable and a separate transformer. I am trying to find out from an actual Beta 58a owner that plugs the mic directly into the PSR3000 what is the correct way to go. Thanks.