The 25-pin DB25 input on the RMB-1075 and RMB-1095 offers an alternative connection for the input signal rather than using the standard RCA inputs. The signal quality is comparable for either connection method, the main advantage of the DB25 being the convenience of connecting a single cable as opposed to five separate RCA cables. While Rotel does not manufacture cables, many audio cable manufacturers carry or can construct an RCA-to-DB25 cable for this purpose. For those wishing to wire their own DB25 cable, Rotel provides the pin configuration for this cable below.

DB25 Pin Assignments

The default password to save the User Default settings is '0000'.

XLR cables use differential designs and, as their name implies, they only let differences pass. They use two signal paths, inverted (negative) and non-inverted (positive), plus a ground. The inverted and non-inverted signals are exact reflections of each other, so where one has a peak, the other has a trough. This differential design helps cancel any noise injected in the line and may provide better sound than RCA connections.

Single-ended signals use a single conductor in the cable which typically also uses a shield wire to make a ground connection. The shield cannot be 100% effective, so noise picked up by the signal conductor becomes forever part of the audio signal is amplified through the signal path.

The PC-USB input on your Rotel product supports two different audio classes.  USB Audio Class 1.0 is the original format and supports up to 96kHz audio. This is the default setting as all computers will support this class. USB Audio Class 2.0 is a newer standard and supports audio up to 192kHz. Not all USB hardware supports this format but most computers made in the last 5 years should support this.

Do note that if you are using a Windows PC for audio and wish to play 192kHz Audio, you will also need to install drivers on the computer to handle this. The USB audio drivers are included on a CD with the product, or they can also be downloaded here.