Audio Research LS2B: hissing noise from a channel

I was trying to mod my Audio Research LS2B following a few treads that recommend replacing MIT Multicaps caps with Dynamicaps. As suggested, I turned the Dynamicaps in the left channel in the opposite direction and turned the preamp on: what a surprise! After a strong puff sound there was black smoke coming out of the Dynamicaps. I then turned them around, and also replaced the caps in the right channel following the original direction of the MIT Multicaps (with 2 new Dynamicaps, I got 4 of them), and the right channel works great. However, there is now only a strong hissing noise coming out of the left channel. Would anyone know what did I blow in the process? A MOSFET, the Sovtek tube? The sounds in the right channel has a significant improvement over the Multicaps, but now I don't have the left channel. Can anyone help? Thanks in advance.
Another Audio Research component bites the dust. It will never be the same again unless you return it to Audio Research for repair.
repair time
I did return it to Audio Research and they've done a great job, it sounds excellent now.
Sounds to me like it could of been a constant current source/ Fet in that channel.