Loud crack in the left channel - tube issue?


Hi -

We use a HAG-USB, a Musical Fidelity Trivista DAC and Musical Fidelity A308. This afternoon, my wife stated she had heard several loud cracks from the left channel. Then I heard a loud thump too and turned everything off. An hour later, I turn things back on and the left channel is dead. Turn them off again plug in an Ipod to determine if it is an amp or DAC issue - now everything is back to normal. Any suggestions as to what is going on? I was under the impression the small tubes in the MF DAC were bomb-proof?

Cheers,
Soren
mogelsvs
Probably issue with the tubes which has happened in my system.

How old is the DAC?
I am the second owner of the dac, so I can't say how many hours it has on it. I guess I will have to find somewhere to get the tubes replaced here in the DC area.

Cheers,
Soren