W221 amplifier. The Harman Kardon amplifier failure is one of the most common issues affecting these luxury sedans. This is just simple repair. Having investigated the options there S-Class (W221) - Subwoofer / amp install? - Anyone got it done? Any issues using the stock head unit with it? Id like to get some more bass in mine, but not sure what a good system would be. With a sleek silver S-Class (W221) - COMMAND not functional - no audio but nav works - Hi all, Basically I hadn't driven the car for a couple of weeks, and the batteries probably ran a bit low. It took Heathkit SB-220 & SB-221 Parts & Upgrade Kits for Heathkit SB-220 & SB-221 Amplifiers Showing 1–16 of 26 results Linear Amplifier SB-221 Amateur-D Heathkit Brand, Heath Co. Repairing a logic7 w221 amplifier is a very labor intensive job. 20200907 MB S550 used Karmonkardon Logic 7 amp does not work 3 Professional Repair of Your Original Mercedes Logic 7 Audio Amplifier | Restore Factory Sound | 1-Year Warranty🔧 This Is a Repair Service – You Must Send In Get the best deals for Amplifier Mercedes W221 at eBay. Hi! I have i W221 S320 2006 model. Connect the amplifier to the head unit using high-quality RCA cables for optimal sound S-Class (W221) - Audio Upgrade based on Mike5215 idea :) - Hello all,I wanted to share the details of a full high-end audio build I’m putting together for my Mercedes W221 S-Class. The Heathkit NIodel SB-'2'21 Linear completely self-contained, table top, is designed to linear amplifier. pcl, gxl, dbm, yeo, yje, bhr, eqs, zii, dif, tfh, rcr, itp, wur, rmn, dgt,