MCINTOSH-service-manual维修手册vics_bulletins

101IllnfoshMODEL NUMBER MA 230DATE June,1964MODIFICATION MA 230 serial 10C00 to 13C03 to increase overall gain.DESCRIPTION This modification may be incorporated in MA 230units having the above serial numbers to increase theoverall gain.The gain is increased two ways:1.The feedback loop in the phono-tape headinput stages is modified by changing the inputtransistor emitter resistors (R 17 and R 18)from1,8K5%名watt to1,2K5%色watt.2.The volume control taper characteristicis changed to allow more amplification at alower setting of the control knob by changing theresistors connected to the rear of the loudnesscontrol (R 39 and R 40)for 47K 10%watt to100K10%老watt.These modifications have been made in all MA 230with serial numbers above 13C03MA230