Harman Kardon HK2500
Documentation on the Harman Kardon HK2500 is thin — the record consists of a single source and a handful of specifications. What is known: this was an integrated amplifier, and the surviving figures suggest a serious piece of high-current engineering.
The specs on record: 75 watts per channel into 8 ohms, frequency response from DC to 100 kHz, and total harmonic distortion rated at 0.01%. That DC-to-100kHz response figure is the tell — it points to the wideband design philosophy Harman Kardon pursued in this era, where the amplifier's bandwidth was deliberately extended far beyond the audible range to preserve phase accuracy and transient behavior within it. The 0.01% THD figure, if taken at face value, puts it firmly in the company of the better-specified integrated amps of the late 1970s.
Beyond those three numbers, the record goes quiet. No production years, no original price, no dimensions, no inputs or outputs, no circuit topology — none of it has surfaced in surviving period sources. Interestingly, the magazine chunks in the archive are of little help: Audio (January 1979, p.15) ran a Harman Kardon advertisement discussing wow-and-flutter measurements in cassette decks, not amplifiers, and the other chunks cover the hk3500 cassette recorder and unrelated Rotel products. The HK2500 itself appears not to have been reviewed in the publications we track.
So this page is honest about its limits: the HK2500 is a real, evidently capable integrated amplifier from a brand known for wideband design, documented by exactly one source with three specifications — and nothing else. If you own one, or have a service manual, the archive would love to hear from you.
- Type: Integrated amplifier
- Power output: 75W per channel into 8 ohms
- Frequency response: DC–100 kHz
- THD: 0.01%
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