Marantz - DPM-7 - Digital Processing Amplifier - Prototype - made by Philips/Marantz R&D - Solid state power amplifier

Marantz DPM-7 – Digital Processing Amplifier – Prototype (Philips / Marantz R&D, 1985)

An original Marantz DPM-7 prototype is offered, developed within the joint Philips & Marantz R&D program in the mid-1980s. This device is not a commercial product, but a rare development model of which only a limited number of test units were built.

The DPM-7 is designed as a hybrid digital-analog design, combining experimental digital signal processing with a full, conventional analog power amplifier. The power-amplifier section is built around an original, standalone Marantz power-amp circuit board, comparable to standard Marantz architecture from the same period. There are only 60 fully functional DPM-7s in circulation.

Functional status of this unit.
• Power amplifier: fully operational and tested.
Suitable for normal musical use as a standalone stereo power amplifier.
• Spectrum display / graphic analyzer: active and functioning.
• Volume control and basic operation: functional.
• Other digital/DSP-related functions: not demonstrably active and not further tested. These functions are present in hardware, but the operational status is unknown.

Important distinction
The power amplifier section operates independently of the digital experimental modules. This makes the device not only interesting as a development prototype, but also practically suitable for listening.

Technical context:
• Hybrid digital-analog design
• Analog stereo power amplifier with classic Marantz construction
• Digital control and signal modules as an R&D platform
• Digital signal philosophy around 44.1 kHz / 16-bit
Real-time spectrum visualization
• Prototype implementation: functionality may vary from unit to unit

Available (not confirmed active) development modules
DSP architecture (Audio Signal Processor concept)
• Graphic equalizer with presets (m1 to m4)
• Dynamic level / release-time parameters
• Reverberation / absorption parameters
• Special effect selector

These modules are part of the original design, are physically present at the PCB level and on the front panel, but are not actively mounted.

Construction
• Fully metal chassis
• Large ventilation section in the top plate
• Advanced front display with segment control
• Extended front panel with parameter-driven control

Cosmetic condition
Neat and well-kept. Front panel in good condition with clear markings. Signs of use appropriate for age and prototype status. Physical data:
• Year built: 1985
• Weight: approx. 18 kg
• Dimensions: approximately 43 cm wide × 18 cm high
• Brand: Marantz / Philips


Includes
• R&D schematics that were created by a professor at the time, who was working at Philips, and thus obtained the object.
Netting knot

Carefully packed and shipped with insurance.