Category:Technics RS-M270X

English: The 1981 Technics RS-M270X was the last model in the M85 family of high quality, direct-drive, but only two-head decks (M45, M65, M85, M88 etc.), which was introduced in the 1979-80 model year. It was also the company's first deck with the dbx noise reduction system. Panasonic was the biggest supporter of the dbx NR (in fact, the only big one). They, and the David Blackmer's dbx, Inc. urgently needed to release a consumer version before Ray Dolby releases his new system (the Dolby C). So, Panasonic slapped a noise reduction board onto the existing (and already outgoing) model M45, with only minor changes to the faceplate, and rushed it into the sales chain. Apparently, the platform was designed with such expansion in mind - the plastic frame of the older M45 has all the necessary threaded posts for an extra board. The designers had to relocate the actuator for the Rec/Play switch, and it was good to go. The deck is otherwise mechanically and electrically identical to the M45. It claims a very good 0.035% WRMS (or 0.1% DIN) wow-and-flutter, for what it's worth, and weighs the very respectable 6.2 kilos - almost the same as the M45, but much lighter than M85 and M88. There is no bias adjustment (which was included in the M85 and M88), but, hey, it's only a two-head. Typically for Technics, the deck uses lots of custom Panasonic ICs, which are absolutely unobtainium in the 21st century.
The dbx noise reduction board of the M270 is a one-of-a-kind monstrosity with 9 ICs (including the Rohm BA651+BA652 chipset and a bizarre virtual-ground power regulator) and as many as 43 discrete transistors. All of this for just two stereo channel (a two-head deck did not need four). The schematic is similar to the RP-9024 outboard NR processor; the added transistors are mostly for switching between record and playback modes. Later in the same 1981 Panasonic announced the low cost, single chip AN6291 IC, which would become the company's choice for all dbx-equipped decks from the 1982 model year until the system was retired in 1988 (or 89?).