for the initial question, I own a new Shiva 1x12 EL34 combo (and love it). As I have never heard an old one I can't compare both soundwise but if you have any other questions regarding the new Shiva I might be able to help...
Hi Alex, thanks for the input. I have an older model 6L6 with boost mod done at factory. What i am interested in are the bright switches and fx loop. Do you notice a big difference when bright switch engaged? Clean channel, dirt channel? If so, is it a good thing or just fluff? Thanks again. And congrats on your new Shiva. It's a wonderful amp.