Yamaha RX-670

This page gets complicated. The research sources point to two different products with nearly the same name. One is the RX-670, a vintage stereo receiver with a phono stage, described in a Craigslist listing as "Made in Japan." The other is the RX-A670, a modern 7.2-channel Aventage-series AV receiver. No source says they are the same model, and the evidence suggests they are not. The RX-670 appears to be an older stereo unit, while the RX-A670 is a contemporary home theater piece. What follows covers what is documented for each, labeled as such.

For the vintage RX-670, the record is thin. It is mostly usage context from forums and a single classified ad. A Craigslist listing in Minneapolis offered one in "Exc. Condition" for $100, noting it was made in Japan and included a phono stage. An owner on the Salk Silk Monitors forum described using one as a preamp front end feeding a separate amplifier, with an iPhone through a DAC into Polk speakers on the "B speaker channel." That same thread has a complaint that the unit seemed underpowered compared to a lower-priced Yamaha, and that ARC "doesn't seem to work on this one," though the grammar is ambiguous about which receiver is being criticized. The only other reception note comes from Audioholics forums, where an owner in a 5.2.2 setup reported "a low volume, mid to low static type sound. Like intermittent staticy clicking." No power ratings, dimensions, or production years are documented for this version.

The RX-A670 is better documented, though still thin for an enthusiast. A Vietnamese retailer, audiohanoihifi.com, gives the most complete specs. It lists a 7.2-channel AV receiver with Dolby Atmos and DTS:X (5.1.2 channels), 80W per channel into 8 ohms (20Hz - 20kHz, 0.09% THD, 2-ch driven) and 145W per channel (8Ω, 1kHz, 10% THD, 1-ch driven). It has four HDMI inputs and two outputs, with 4K Ultra HD support including HDCP 2.2, Dolby Vision, Hybrid Log-Gamma, and BT.2020. Decoding covers DSD 2.8/5.6MHz, FLAC/WAV/AIFF up to 192kHz/24-bit, and Apple Lossless. Streaming is handled via Wi-Fi, Bluetooth, AirPlay, and Spotify. A phono input is present. The chassis uses a machined aluminum frame with heat-sink grooves on top, and the center footer uses Yamaha's A.R.T Wedge anti-resonance technology. Dimensions are 162 (225 with antenna) x 435 x 330 mm, and weight is 8.3 kg. Top Ten Reviews noted the receiver has "an exceptional power output" but cautioned that it "only has 4 HDMI inputs." One UK classified listing asked £180 for a used unit.

Missing from the record: production years, original pricing, and any detailed circuit or DAC information for either model. If you own an RX-670 or RX-A670 and can fill in the gaps, particularly the relationship between the two names, the archive would welcome the correction.