Marantz HD-AMP1 Integrated Amp

Description

The Marantz HD-AMP1 is a compact digital integrated amplifier designed to bring serious two-channel performance, high-resolution digital playback and a sophisticated headphone amplifier into a remarkably small chassis. Introduced in 2016, it was part of Marantz’s HD Series, alongside the HD-DAC1 and HD-CD1. Rather than being a conventional stereo amplifier with a DAC added as an afterthought, the HD-AMP1 was conceived around digital audio, with a high-resolution ESS SABRE DAC, asynchronous USB input, DSD support and Marantz’s proprietary HDAM-SA2 circuitry. Marantz describes it as an amplifier engineered to “the highest Marantz purist audiophile standards.”

The amplifier section uses a Class D output stage rated at 35 watts per channel into 8 ohms and 70 watts per channel into 4 ohms. That may look modest compared with full-size integrated amplifiers, but the 4-ohm rating gives the HD-AMP1 useful current capability for a wide variety of compact and medium-sized loudspeakers. Marantz specifically designed the output stage to handle speakers down to 4 ohms.

Digital playback is one of the HD-AMP1’s major attractions. Its ESS SABRE ES9010K2M DAC accepts PCM signals up to 24-bit/192kHz through the optical and coaxial inputs, while the rear asynchronous USB-B input supports PCM up to an impressive 32-bit/384kHz. USB also supports DSD64, DSD128 and DSD256 (2.8, 5.6 and 11.2MHz). A front USB-A connection provides compatibility with iPod/iPhone devices and USB storage.

Marantz’s HDAM-SA2 modules are incorporated into three sections of the circuitry: the analog front end, the DAC’s current-to-voltage stage and the dedicated headphone amplifier. The headphone section includes three selectable gain settings—low, mid and high—making it possible to accommodate headphones with substantially different impedance and sensitivity characteristics.

Connectivity is unusually comprehensive for such a small amplifier. There are two analog RCA inputs, one coaxial digital input, two optical inputs, rear USB-B, front USB-A and a dedicated subwoofer output. The inclusion of a subwoofer output makes the HD-AMP1 particularly attractive for compact two-channel systems where a small monitor speaker is combined with a powered subwoofer.

The physical design is quintessentially Marantz. A brushed-aluminum front panel, wood-look side panels and the company’s distinctive circular “porthole” display give it a luxurious appearance despite its compact footprint. The unit measures only about 12 inches wide and weighs approximately 12.8 pounds.

Contemporary listener reactions emphasized the HD-AMP1’s combination of features and sound quality. One What Hi-Fi? forum participant summarized the appeal by noting its “good connectivity” and describing the specification as well thought out, particularly the USB, multiple digital inputs, adjustable-gain headphone output and integrated DAC. Another owner described its sound as “more detailed” than a Marantz M-CR603, although that listener ultimately wanted greater scale and soundstage with relatively insensitive speakers.

Overall, the HD-AMP1 is an unusually complete compact integrated amplifier: a capable Class D power amplifier, high-resolution DAC, DSD-capable computer interface, headphone amplifier and analog preamplifier functions are all contained in one attractive chassis. Its relatively modest power output makes speaker matching important, but with appropriate speakers it offers a particularly elegant solution for a high-quality desktop, small-room or minimalist two-channel system.

Product Specifications

• Type: Compact digital integrated stereo amplifier
• Amplifier Design: Class D
• Power Output: 35W + 35W into 8 ohms
• Power Output: 70W + 70W into 4 ohms
• Frequency Response: 20Hz–50kHz
• THD: 0.05%
• Signal-to-Noise Ratio: 105dB
• Speaker Impedance: 4–16 ohms
• DAC: ESS SABRE ES9010K2M
• Digital Processing: Up to 32-bit/384kHz via USB-B
• DSD Support: DSD64, DSD128 and DSD256
• Digital Inputs: 1 coaxial, 2 optical
• USB Inputs: 1 rear USB-B, 1 front USB-A
• Analog Inputs: 2 pairs RCA
• Subwoofer Output: Yes
• Headphone Output: 6.3mm
• Headphone Gain: Low / Mid / High
• DAC/Analog Circuitry: Marantz HDAM-SA2
• Digital Filters: Marantz Musical Digital Filtering, two selectable modes
• Dimensions (W × D × H): 12.0 × 13.9 × 4.2 inches
• Weight: 12.8 lb (5.8kg)
• Finish: Black with brushed-aluminum front panel and wood-look side panels