Marantz PM-8 (c. 1981–1983)

The Marantz PM-8 is one of those amplifiers that the period press took very seriously. Stereo Review ran a Hirsch-Houck Labs test report that called it "one of the finest amplifiers we have tested," and the measured performance backed that up. This was the flagship integrated amplifier of Marantz's "8" series, a line that also included the ST-8 tuner and SD-8 cassette deck — produced during the Philips ownership era. The review described it as "not inexpensive" and part of a "new generation of high-quality components."

What made the PM-8 distinctive was its construction. It used a dual-mono layout — each channel had its own power supply and rectifier, fed by a large toroidal transformer — to minimize crosstalk. The output stage ran in Class A at low levels and switched to Class AB for higher output, a design intended to eliminate crossover distortion. The signal path was direct-coupled with no coupling capacitors, and the phono stage used FETs for high input impedance. The rear panel included separate preamp-out and main-in jacks, allowing the PM-8 to be used as a standalone preamp or power amp.

The measured numbers from the Hirsch-Houck report were exceptional for the era. Rated at 125 watts per channel into 8 ohms (20 Hz–20 kHz, ≤0.03% THD), it delivered 200 watts into 4 ohms. Dynamic headroom at 4 ohms measured 1.7 dB. The damping factor was about 200 at 8 ohms, and frequency response at 1 watt was essentially flat from 15 Hz to 20 kHz (–0.1 dB), rolling off to –3 dB at 100 kHz at full power. Phono RIAA equalization held within ±0.2 dB across the band. The phono input overloaded at about 150 mV at 1 kHz and about 700 mV at 20 kHz. Signal-to-noise measured about 74 dB unweighted for the high-level input and 80 dB for phono — notably lower than the owner's manual rated spec of 100 dB for high-level, a discrepancy worth noting. The owner's manual also specified THD at 0.02% versus the 0.03% cited in the review. Intermodulation distortion measured around 0.02–0.03% in testing.

The PM-8 was a substantial piece of hardware: 470 × 156 × 380 mm and 17.5 kg, consuming 470 W. Inputs included two phono stages (one MM, one MM/MC), tuner, CD, aux, and two tape loops, with tone controls that could be defeated entirely, a loudness contour, subsonic and high-frequency filters, and a headphone jack. Exact production years and original retail price are not documented in the archive's sources.

One note on classification: some database listings refer to the PM-8 as a "receiver." That is incorrect — it has no tuner section. Both the Stereo Review test report and the service documentation describe it as an integrated amplifier.