25. The power supply of the M17 under DC and BAT modes

The desktop mode of the M17 benefits from the more abundant energy of the DC power supply, faster power response, and lower internal resistance of the power source. Also, the power supply of the internal amp has been increased to ±11V, and the driven capacity has reached a desktop-grade 3000mW+3000mW in balanced output.
In addition, thanks to the DC mode, we also designed the BAT/DC switch. In the DC mode, the internal battery will not work. This helps to better protect the battery. Therefore, the M17 can be placed on the desktop for a long time and used as a desktop device yet without worrying that the battery would be degraded.

Figure 1 is a schematic diagram of the energy flow under the battery power supply. Under the battery power supply mode, the M17 is completely battery-powered, so it is particularly convenient to take it around anywhere you want.

Figure 2 shows the energy flow when plugging in a 12V/3A DC adapter, and the DC/BAT switch is at the BAT position. At this time, the M17 is powered by battery and DC hybrid power supplies. First, the 12V power source will flow into the battery through the internal circuit, and then the battery will power the whole device. We can imagine the battery as a large pool with water in and out. In the hybrid power supply mode, the battery capacity can be kept full at all times, which is suitable for use in short-term fixed scenarios. At this time, the battery life will be longer than in pure battery mode.

Figure 3 shows the energy flow when plugging in a 12V/3A DC adapter, and the DC/BAT switch is at the DC position. At this time, the M17 is completely powered by the DC adapter, and the power supply of the internal THX788+ headphone amplifier is also increased to ±11V. So it can drive most headphones thanks to the larger voltage swing and output power. For sure, heat generation will be more serious in this mode. But don't worry, we can put the M17 on the included cooling fan stand for effective heat dissipation. In DC power supply mode, the battery life can be greatly extended because the battery is not involved in the working process at all. So we have no worries about the battery.