A few reasons why we use DIN connections:
Naim use three types of DIN connector:
- DIN4 (4 pins in a 240 degree arc) - Typically used for pre-amp signal OUT and smaller power amp signal IN. It can carry signal as well as 24V DC when used between a suitable Naim Power amp and pre-amp where the power amp's power supply also provides power to the pre-amp.
- DIN5 (5 pins in a 240 degree arc) - Typically used between a power supply and a pre-amp or phono stage where it carries signal as well as 2 x 24v DC.
- DIN5 (5 pins in a 180 degree arc) - Typically used on source interconnects, inputs and input/outputs.
This picture shows DIN4 (240), DIN5 (240) and DIN5 (180)
So why do Naim prefer to use DIN connectors?
The obvious reason: DIN connections sound better than RCAs...
The phono plug, or RCA connector, as best as anyone can remember, was designed decades ago as a direct current (DC) power connector. Its design properties do not lend themselves to transferring music signals that have very low voltages (less Than 5 volts) of alternating current (AC). This is true - no matter how good the RCA plug is or whether it is made with gold, etc.
The first difficulty with the RCA connector is that it has a high-frequency capacitive impedance of around 200 ohms; unfortunately, the typical cable that connects the two RCA plugs together has an impedance of about 50 ohms. In this situation, the two RCA connectors on either end of the cable act as reflective walls at higher frequencies and bounce information back and forth, trapping the signal and extending the decay time of the signal that is trying to pass from one component to the other. These reflections have an effect on musical information and are especially harmful to low-level signals, particularly quiet harmonics and underlying instruments, where the ringing that is generated by the loudest instruments will smear the smallest signals. The result is that the quiet instruments will blur or fade away when the loud ones come along. The complexities of the music and the tones of individual instruments get lost.
The DIN plug has an impedance that is similar to the cable. It does not reflect like an RCA plug.
Furthermore, the system ground (which should be a stable connection point to which all signals and power supplies are referenced) is absolutely critical to the sonic performance of your hi-fi. A single reference ground point is important so that signal details are not lost in the small, yet significant voltage differences inevitable with separated ground paths.
Many manufacturers point to the great trouble they take to "star ground" everything. Sadly, this is all wasted when you connect your system together with RCA-plugged cables. Why?
When you connect, for instance, a CD player to a preamp with RCA-plugged cable, you automatically have two separate ground wires - the left and right shields going between them. This creates a ground loop, which degrades the musical performance dramatically, and negates any efforts that were taken to ground the internal circuits properly.
If you were to connect these same two components together with DIN-plugged Naim interconnects, you would have only ONE cable with only ONE ground shield surrounding both the left and right signal wires. Hence, only one ground path for each connection and no ground loop.