This 1970's Champ has a simple enough circuit to stay practically unchanged from the Blackface era. This amp has stayed all original, with the exception of a changed Celestion Eight 15 8" Speakerl. Aesthetically, it shows signs of prolonged storage, with oxidation on the chassis, though the structure has held up perfectly well. The sound is particularly great on this particular champ, which makes them an excellent purchase for the money.