The top of the 330/430/730 receiver trio - twin-powered HK receivers are still respected for their sound.
Sold-price reading for this model →Solid-state American chassis from the 1960s-70s: the usual failures are dried electrolytics, dirty selector switches and, on receivers, the dial lamps and the tuner front end. Original wood cabinets and faceplates drive the price.
Marks that can be entered for this maker: Model / catalogue number, Model / catalogue number, British capacitor code (Hunts, Mullard), Japanese capacitor code (Nichicon, Chemi-Con, ELNA), EIA component code.
The introduction year is not documented, so the model narrows nothing.
Sold-listing reading: fair $152, good $201, excellent $375 USD · 6 sold listings (thin sample — indicative only) · as of 2012-09 – 2024-10. Classic Receivers (Harman Kardon page) eBay SOLD-price table (https://classicreceivers.com/harman-kardon-values), 6 completed listings; fair/good/excellent are the observed minimum / median / maximum of those sold prices, not condition grades.