Digital interconnect for analog. Is 110 ohms too much for analog cable?

I believe 110 ohm is AES/ EBU balanced digital.   He probably meant 75 ohm analog RCA

According to aes.org,  coaxial digital connectors are 75 ohm and "twisted pair" digital cables are 110 ohms.   You will find an AES/EBU connector (XLR) on 110 ohm cables .  Impedance and bandwidth are not the same .   I think you were given bad advice.,   Any quality RCA cable should be fine.