Znalazłem ciekawą opinię o różnicach pomiędzy podobnymi modelami es : 870-890, 970-990
From 1990 onward, the ES decks were from one year to the other simply facelifted, slightly facelifted or very much facelifted, with little mechanical improvements to justify the new name. So: the 990 is a 970 and the 890 truly is nothing more than a 870 - both originals being from the previous year\'s lineup... The K990 is a japanese TC-K333ES-A, the K890 a TC-K222ES-A. Only Japan saw the real 13,6kg fully copper-plated TC-K555ESA, visually identical to the TC-K990ES. Then there was the TC-K555ESJ - ultimate model -refinement- of the "classic" ES period.