I understand about JCM 900 being Marshall and all... But what's the SL-X version?

Just came across one on eBay...
one more pre-amp tube over the other 900s

therefore more gain, more modern sound, but imo, lacking balls

Kiss used them for a few years, theyre good amps, but aim for older 900s if you can!

im selling mine on ebay if you lot want a look

type jcm900 mk3 and its there the 2100