There are two reasons to use three smaller transformers instead of one big transformer. First, Smaller transformers are more stable under high current swings and have less chance of humming during high current peaks. Second, yet most important, each transformer is used for its dedicated area of operation. One for the processor, one for the motherboard and one for the peripherals. A streamer supply has a highly peaking current load, and all currents add up in the transformer core and interact with each other. By separating the main areas of a streamer, in each transformer, the interaction is less which will improve the final sound quality.
Due to its intrinsic properties, a capacitor buffered power supply does not draw a continuous, but a highly peaked current. Each 100Hz capacitor is filled up for the full cycle in only microseconds, depending on the duty cycle of the power supply. The higher the capacitance and the lower the inductance (and Rdc) of the transformer, the lower the duty cycle and the higher these peaks are. These peaks introduce large Hf-noise in power supplies. In Pink Faun power supplies, we use high inductance power transformers (low field saturation in the core) and pi-filtering to keep the peaks at a minimum and thus Hf noise. The less rubbish in, the less we have to filter later.
Multiple power rails
All loads, in the end, come together in the source of power. In this source, they interact which results in harmonics and intermodulation noise. The earlier all separated loads are split in the device, the less they interact rendering the lowest initial noise in power supplies.
Also, by using a lot of smaller separated and regulated supplies, we can keep current loops very minimal and local, which also will reduce the spread of EMC inside the device. This is why Pink Faun streamers use separated rails for dedicated areas and a separated regulator for each load. We take extreme care in adding these power supplies all together in