I own a LSC and have spoken with Mesa regarding YJ's. Yes, you will set up a class A circuit. The amp will sound similar to a LSS, but it will be impossible to replicate the sound exactly. I was informed by Chris at Mesa that the LSS and LSC utilize different transformers, and therefore will not sound exactly the same, but you can come close. I purchased them for future use but have not tried them yet. One thing to be aware of, use Mesa tubes to maintain your warranty. The JJ's they come with will void your warranty. You will not void your warranty unless the YJ's themselves fail and cause damage as long as you use Mesa tubes. I purchased the YJ's without tubes and picked up Mesa's EL84's. I'm still exploring the 6l6 tone and it will be a while before I pop in EL84's or EL34's (Mesa NOS Siemens) which I also purchased. Another note on the YJ's: The circuitry in the YJ's according to Mesa is not quite transparent which is another reason the LSC will not sound exactly like an LSS. Give them a try, I'll bet it will still sound awesome if not exactly the same....Mojo