Amazing condition for it’s age. Was in storage, only issue is minor oxidation on buttons as seen in the photo and visual oxidation on the top. I didn’t try cleaning those parts because I didn’t want to risk damaging it. I work on electronics and decided to open it up and ensure everything looks good as seen. I cleaned the back connectors with 99% alcohol and Q-tips. And yes it is fully functioning!

Amazing condition, this one is in storage, will take more pictures soon.

This preamp is in very nice physical condition. It powers on and all the inputs, outputs and controls work as they should however the output is a little distorted. It may only need a cleaning of the controls. Sold for parts.

Amazing condition, this one is in storage, will take more pictures soon.

Amazing condition, this one is in storage, will take more pictures soon.

More pictures will be added within a day.

For sale: Harman Kardon HK 725 + HK 770 Ultrawideband Pre and Power amplifier from the golden times from Harman Kardon. A beautiful build and easy to serve versetile vintage audio sleeper. Harman Kardon HK770Stereo Power Amplifier (1982)SpecificationsPower output: 65 watts per channel into 8? (stereo)Frequency response: 20Hz to 20kHzDamping factor: 50Input sensitivity: 1.2VSignal to noise ratio: 123dBDimensions: 385 x 72.5 x 320mmWeight: 10.1kgYear: 1980 Stereo Pre-Amplifier (1980-82)SpecificationsFrequency response: 1Hz to 150kHzTotal harmonic distortion: 0.005%Input sensitivity: 2.3mV (MM), 145mV (line)Signal to noise ratio: 90dB (MM), 106dB (line)Dimensions: 385 x 72.5 x 320mmWeight: 4.2kgYear: 1980 Please do not hesitate to contact me regarding this offer or more detailed shipping and handling fees. Also feel free to follow my channel for more mostly vintage audio and speaker gear.Happy bid!

Works and sounds great,very nice phono section,2 tape monitors.Has a few scratches on the top edge near the front corners.USA shipping only.No returns unless damaged in shipping. You have 3 days for notify me for a refund.Local pickup is fine and you can pay with cash.

sehr schöner Harman/Kardon HK 725 - Vorverstärker - aus 1980-84 - Made in Japan/ not tested -Hobby-Projektaufgabe Classic, Retro, Vintage selten, für Sammler und Liebhaber - - aus Hobbywerkstattauflösung ausgemustert, wird nicht mehr gebraucht überlasse die komplette Wiederinbetriebnahme dem Fachmann, die Hobbywerkstatt wird aufgelöst, als techn Laie kann ich den PreAmplifier - Vorverstärker nicht testen Stereo-Receiver / Retro, Vintage, Classic gebraucht, Farbe silber, optischer Zustand: gut, keine übermässigen Benutzungspuren vorhanden, wiegt 8 kg, Schukostecker wurde wohl mal drangebaut verkaufe als defekt bzw. Ersatzteile, as only Spare-Parts, braucht wahrscheinlich technische Inspektion --- 220 Volt, ohne weiteres Zubehör, Zustand wie auf Foto, ohne Bedienungsanleitung Privatverkauf ohne Garantie / ohne Gewährleistung / ohne Rücknahme Bieter aus dem Ausland willkommen / Foreign buyers are welcome Versand/Porto nur versichert nach aktueller Preisliste DHL / HERMES Ausland nach Absprache - z. B. Südkorea ca. 50,00 Euro

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 .