HARMAN KARDON : HK 715 : HK 725 : HK 770: HK 100M : Very rare vintage stereo system : The system consists of DC power amplifier , DC power pre - amplifier DC fm / am tuner and lastly DC cassette player . This system has been imported and works through a lower voltage than that used in the UK . There is a voltage converter supplied with the units to enable use within the Uk . Specifications are as follows : Twin Toroidal power ultrawideband direct current amplifier , 2 channel x 2 x 65 watts into 8 ohms , 20 Hz -20 kHz , damping factor : 50 , Input sensitivity 1.2 v , signal to noise ratio 123 dB , A - B four speaker outlet , dimensions 385 x 72.5 x 320 mm , weight 10.1 kg . Direct current pre-amplifier with switch button bass/ treble control function , frequency 1 Hz -150 KHz, total harmonic distortion 0.005% , input sensitivity 2.3 mV ( MM ) 145 mV ( line ) signal to noise ratio : 90 db ( MM ) 106 db (line) , dimensions 385 x 72.5 x 320 mm , weight 4.2 kg . Direct current tuner with am / fm step up / step down tuning , 87.5 MHz on frequency display , 96.2 MHz on frequency counter 999 KHz on frequency display , confirm that frequency reading on frequency counter is 1458 KHz : Direct current cassette player : Professionally serviced with receipt . For those who are familiar with this system words are few , for those who are not , they just do not make them like this anymore . Full metal chassis construction on all components .The pre-amplifier has a unusual switch bass / treble configuration with assisted EQ switch for refined precision listening , The power amplifier is heavy to lift and has several heat sinks on either side maintaining a good transference of heat for continuous long use . The cassette deck has various options for metal & normal tapes : And finally the tuner has a step up/ step down function for precise tuning ensures smooth transition from station to station. Light damage to the front of the power amplifier case (see picture nine ) and some usage marks to units over the years but given this system is over forty years old , the units are in good condition .This sale is for payment through eBay strictly and collection only as the system is to heavy for postage , plus the possibility of damage in transit enforces the reason for collection .In saying that I am willing to work with a buyer who wishes to arrange collection through service of a courier, but please note that I will not be held responsible for any damages which may occur whilst in transit. Please note the hi-fi stand is for display purposes only and is not included in the auction . Please DO not waste your time asking for a particular unit of the set to be sold separately, you will not receive a reply , serious inquiries welcomed .