MC2105 input board serial#
I have two 2105s, and they each are equipped with the 043-795 input boards. Apparently Mac interchanged them during production as the 2100 is the 2105 without meters. Moreover, there are minor changes in the number of resistors, and some values between the two boards. I recapped the signal path caps in the input and output boards of both, using Dayton, Nichicon, and Vishay-Spragues - some polypropylene, others electrolytic. I also added .1 polypropylene by-passes to several of them. I left the large filter cans (as suggested by MacIntosh techs), but added 47uf polypropylene by-passes on each. They sound quite lovely and improved.
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MR77, MC275, MC240, 2-MC2105s, Crown D150a. Crown IC150, Musical Design SP-1, Michell Giro SE with Benz-Micro Glider, Marantz SA8001; JBL Paragon (with 150c woofers, and added 2405s (alnico), JBL C37 lowboys (with D130s and LE175s)