Marantz DP870

The Marantz DP870 was the company's first high-end reference digital processor. It's a separate outboard D/A converter, designed to sit alongside the DP850 transport. The design is 18-bit with dual DACs and what Marantz called "36-bit signal processing." It uses a DSP-based chipset, with selectable digital filter modes (1/2/3) on the front panel. The unit handles 32kHz, 44.1kHz, and 48kHz sampling rates. Coaxial and optical (TOSLINK) digital inputs are selected with a rear-panel switch - though there's no optical input, and only 44.1/48kHz rates are accepted on the digital side. A second rear switch handles 44.1kHz vs 48kHz input selection, and there's also a "mode" switch.

Output is variable through a front-panel volume knob, rated at 2.0V with frequency response of 2Hz-20kHz ±0.5dB. Power consumption is a modest 20 watts. Inside, the build is described as "lots of Elna capacitors and good construction," per The Vintage Knob. Audio (November 1996, p.54) noted that laserdisc players convey Dolby Digital on an RF carrier, so the DP870 demodulates such signals internally to isolate the bitstream for decoding. It is still a stereo D/A converter, not a surround processor. A later Audio piece (January 1997, p.32) compared it favorably against other two-box AC-3 setups of the era. It found the upgrade in sound over cheaper units wasn't as dramatic as the price difference might suggest.

The record on this model is thin in a few places. No original list price has surfaced, and production years aren't documented beyond the mid-1990s context of the reviews. Dimensions and weight are also unrecorded. On the used market, auction results have been reported inconsistently. The Vintage Knob cites both $415 (2022) and approximately EUR 490 for a 2022 sale, with no way to reconcile the two figures.

Known specs, as documented:

- 18-bit D/A conversion, dual DAC, 36-bit signal processing

- Sampling rates: 32 / 44.1 / 48 kHz

- Coaxial and optical digital inputs, rear-panel selector

- Selectable digital filter modes (1/2/3)

- Variable output, 2.0V

- Frequency response: 2Hz–20kHz ±0.5dB

- Power consumption: 20W