From your question, I assume your amps have multiple inputs (e.g., one for XLR, one for RCA). If so, there's no harm in running the phono preamp to one input and the cd to another and then switching as needed at the amp. However, please be sure to check the input impedence of the amp (it may vary from input to input) and the output impedence of the source devices. The ratio should be at least 10 to 1 (output to input -- e.g., no more than a 200 ohm output into a 2000 ohm input impedence) for optimal sound. Also, while some report very good sound from forgoing the phono preamp, others have reported a sound degradation from eliminating the preamp. So, the best course is to try both if possible. I hope I addressed your question. I wasn't exactly sure what you meant by "I don't want to have to switch cables every time"