PrimaLuna EVO 200 Tube Integrated AmplifierCUSTOM TOROIDAL POWER TRANSFORMER Power transformers generate two types of noise, magnetic and acoustic. That's why toroidal power transformers are used in the very best audio products. Compared to standard transformers, toroids radiate about 1 10 the magnetic field that pollutes music and obscures detail. Additionally, the absence of an air gap typically means toroids have an 8: 1 reduction of acoustic noise. As transformers are the most expensive