Since about 1994, American brands like Krell, Mark Levinson, Martin Logan etc. have built-in frequency sensing software that will disable the power supply if the frequency of the AC is not as specified. The voltage is simple. Most modern transformers come with multiple primary windings for all voltages, so any qualified technician can figure out how to rearrange the wires for different input voltages. Unless you know a very good software engineer and hacker who owns very sophisticated equipment to reproduce the software and chipsets, or to hack into the program, you will have to rely on the manufacturer to convert the frequency.
I would not recommend anyone to try modify the Krell's voltage and frequency. The 110V/60hz models are made differently to the 220-240V/50Hz because of strong EU regulations for the electricity. The warranty will void once any modifications are performed. Do not risk this because Krell gives 5 years of warranty on all new products.作者: 发烧JCPER 时间: 2011-9-11 11:06
如是在原厂改的话,保修照样有效。