You're right about the BMW warranty.
The other problem can be diminished to a degree by using headphones although if you insist on using a super expensive source you may not save a ton. If you do what most of the current hedphiers seem to do which is use a computer source and then use a combo integrated DAC Amp you will be ok. My headphone amps have 3 and 1 tube each. I will say this these guys buy the most expensive and exotic tubes they can though. Like buying B65s (MOV/GEC 6SN7) for up to a grand a pop. My headphone output tubes are 6080/6AS7G but will take Tung Sol 5998s and WE421As if I want to use them.
The other problem can be diminished to a degree by using headphones although if you insist on using a super expensive source you may not save a ton. If you do what most of the current hedphiers seem to do which is use a computer source and then use a combo integrated DAC Amp you will be ok. My headphone amps have 3 and 1 tube each. I will say this these guys buy the most expensive and exotic tubes they can though. Like buying B65s (MOV/GEC 6SN7) for up to a grand a pop. My headphone output tubes are 6080/6AS7G but will take Tung Sol 5998s and WE421As if I want to use them.