Linn Isobarik Revision History
modification date serial number
speaker: Major upgrade: Addition of KU-STONE ceramic absorber, units and back now sealed with gaskets instead of silicone, improved cabinet bracing (Upgrade not retrofittable). Dec. 1991 8293/4
crossover: New 4 ohm external fitted in stand. Facilities for tri-wiring. DMS no longer made as PMS can be used with either passive (4 ohm) or aktiv crossover. 1988 6701/2
treble unit: Cosmetic improvement: Fitted with countersunk screws. Sept.1987 6201/2
cabinet: Crossover now in bottom of speaker accessible from underneath. Facility for converting easily to tri-wiring or to aktiv. 1987 5575/6
midrange units: Improved rubber surround to harder rubber. Apr.1986 4953/4
cabinet: Construction improved (internal sealing and damping). Dec. 1985 4825/6
crossover/treble units: Improved PCB with wider tracks and better layout. Treble units also changed to give a smoother response. Linn logo incorporated on front plate. May 1984 3939/40
bass/midrange Units: Sound-deadening material painted on bass and midrange units. Mar.1983 3000/1
cabinet: Changed from chipboard to MDF and veneered on both sides. Jan. 1982 2859/60
treble unit: Fitted with t-nuts. Oct. 1981 2741/2
wiring: Changed internally to common earth at cannon socket. Mar. 1980 11,035/6
treble unit: Scanspeak treble unit replaced with Hiquphon unit, recognised by two concentric rings on unit. Feb. 1980 10,925/6
midrange unit: Vented. Nov. 1979 10,800/1
damping: Midrange enclosure and cabinet damping changed. Sep. 1978 10283/4
speaker: Active PMS version introduced. 1977  
cabinet: Current cabinet style adopted. Sep. 1976