Denon PMA-390IV (2000)

Name: Denon PMA-390IV
Brand: Denon

The PMA-390IV is a pre-main (integrated) amplifier Denon released in Japan in 2000 at ¥39,800. It's the fourth generation of the 390 line, an improvement over the PMA-390III that Denon positioned as "for next-generation audio." The IV was still made in Japan - the subsequent PMA-390AE moved production to China.

The engineering Denon packed into this affordable integrated is the interesting part. It uses an HC (High Current) single push-pull circuit, inheriting the concept from the UHC circuits used in Denon's S-series. The output transistors deliver twice the current supply capacity and peak current of ordinary transistors. The rectifier circuit uses the same Schottky barrier diodes found in the PMA-2000III. Denon also gave the amp a microcomputer stop mode that halts clock oscillation during listening to keep noise out of the audio path, and separate power transformers for the microcomputer and audio circuits. A source direct function bypasses the tone, loudness, and balance controls entirely.

Rated output is 50W + 50W into 8Ω (20 Hz-20 kHz, THD 0.1%), with maximum practical power of 100W + 100W into 4Ω. Distortion is rated at 0.01% at 1 kHz into 8Ω. Frequency response runs from 5 Hz to 100 kHz (+0/-3 dB). The phono stage handles MM cartridges with 2.5 mV sensitivity and RIAA deviation of ±0.5 dB. Line inputs measure 150 mV/47 kΩ with source direct engaged. A pre-out terminal is built in. The included remote (RC-843) can also operate other Denon components - CD players, MD recorders, tuners, and cassette decks.

No independent period reviews of the 390IV have surfaced in the research, so the record relies on Denon's own specifications and owner accounts. Seller accounts are consistently positive. One seller describes it as a "well-built amplifier, using high-grade internal components and a high-quality circuit design," and another calls it simply a "good integrated amplifier." Used prices vary widely, from around $198 on eBay to £218 in the UK, with one Japanese retailer listing it at US$289.

Known Specifications

Rated output: 50W + 50W (8Ω, 20 Hz–20 kHz, THD 0.1%)
Maximum practical power: 100W + 100W (4Ω, 1 kHz, EIAJ)
THD: 0.01% (1 kHz, 8Ω)
Frequency response: 5 Hz – 100 kHz (+0/–3 dB)
Phono MM input: 2.5 mV / 47 kΩ; RIAA ±0.5 dB (20 Hz–20 kHz)
Line input: 150 mV / 47 kΩ (source direct on)
S/N ratio: 86 dB (phono MM, 5 mV input); 107 dB (line, source direct)
Tone control: Bass ±8 dB (100 Hz); Treble ±8 dB (10 kHz)
Power consumption: 135W; standby less than 2W
Dimensions: 434 × 121 × 338 mm; 7.0 kg (audio-database.com) / 9.8 kg (hirose1117.ocnk.net)