When you see a diagram of an amplifier, there are a lot of symbols saying “connect to ground�. The ground is normally also 0V, and all voltages refer to ground. What the diagram does not tell is how all these ground connections are made. A star ground system is constructed by taking all ground wires and connecting them together in one point. If you draw this, it does look like a star, with a centre-point and a lot of wires going out in all directions form this centre-point. In some of the large recording studio system we have built, we could be talking about 1,000 points that must be connected to ground. In a star ground system, you must therefore use 1,000 wires, so for practical reasons, we can try to use a few thicker wires that run from point to point, just like a school bus picking up kids. This is called a ground bus system. What we want is a connection to 0V. But if we run 1A current in a wire, the small resistance in the wire ( i.e. 0.01 Ohm) and the current will form a small voltage (0.01V) from the start of the wire to the other end of the wire. So if we connect another wire in the middle of the first wire, we are not connecting to 0 Volt, but to half of the 0.01 Volt, or 5mV. This of course is a very small voltage and in many cases it is not of significance. And we can save a lot of wires. In such a bus ground system, you can reduce the ground voltage error by using a thicker wire, thus lowering the resistance. You can also have one wire for small signals and another wire for large currents. The large current will generate a large voltage error, but it does not affect the other wire with the small signals. In the GamuT D200, we have basically a star ground system for the large currents, and two bus grounds for the small signals; one is for the audio input and the other is for the small power ground. The large currents are the charging currents from the rectifiers, and the loudspeaker return wire. Here we are talking up to about 50A, so the wires must go directly to the ground point, which is placed at the midpoint between the two large power capacitors. In our version of the star ground point system, the wires do not have to be very thick, because the centre-point is so small in size that the resistance is very small anyway. In many other power amplifiers, you will see an impressive thick plate or a wide bus of copper. But note that a 10 times longer copper plate must also be 10 times wider to keep the same low resistance! So a short thin wire is better, as it has 10 times less inductance and 10 times less radiation while ensuring the same resistance.