Michell Engineering Apollo

The Apollo phono preamp marks Michell Engineering’s return to electronics after more than two decades away. Designed as two separate modules with its dedicated Muse power supply, this pairing offers a sophisticated technical solution for amplifying MM and MC phono signals. With five gain levels ranging from 40 dB to 73 dB and an RIAA curve calibrated to ±0.1 dB, the Apollo caters to turntable users seeking broad compatibility with different cartridge types.

A fully rethought mechanical and electrical design

The Apollo and the Muse feature precision-machined solid aluminum construction, forming two distinct clam-shaped enclosures. This configuration is not merely aesthetic: each chassis acts as a Faraday cage, blocking external electromagnetic interference while preventing stray emissions from the power supply from reaching the preamp’s sensitive circuits.

The feet are machined directly into the aluminum block to maximize rigidity and mass at the point of contact. This approach differs from traditional add-on feet and contributes to the system’s mechanical stability. Brass badges bearing the Michell name add a distinctive visual touch, while discreet white LEDs replace the bright blue indicators often criticized on contemporary devices.

The embossed pattern on the top surface, initially developed by Trichord, has been reworked by Michell for a more refined finish. All manufacturing is carried out in the United Kingdom, maintaining the company’s tradition of local production established for over fifty years.

Technologies and circuits: the alliance of analog know-how

The Apollo’s technical heart is based on several innovations borrowed from professional microphone amplification. The class A preamplifiers use THAT Corporation 1512 integrated circuits, specifically designed to handle very low-level signals with minimal noise. The subsequent stages employ Texas Instruments Burr-Brown OPA1656s, optimized for audio applications.

Passive RIAA equalization is implemented by a discrete component network, with each capacitor individually measured and then hand-matched to ensure perfect channel balance. This artisanal approach achieves ±0.1 dB precision in the response curve from 20 Hz to 20 kHz, exceeding typical industry standards.

The Muse power supply incorporates an encapsulated toroidal transformer chosen for its low magnetic radiation characteristics. Discrete rectifier diodes feed a capacitance multiplier circuit, followed by high-performance voltage regulators. This system generates two ±24 V DC rails delivered to the Apollo via a proprietary cable made by The Chord Company. This cable uses silver-plated OFC copper conductors, FEP (fluorinated ethylene propylene) insulation, and a multilayer aluminum/Mylar shield, terminated with XLR connectors plated with the ChorAlloy alloy.

The Apollo adds further internal regulation, creating a double filtering barrier. Each amplification stage has its own locally regulated supply, minimizing circuit interactions and maintaining very low supply impedance across the entire audio spectrum.

Flexible configuration and broad compatibility

The Apollo offers five selectable gain levels: 40 dB for standard MM cartridges of 5 mV and above, 50 dB for lower-output MMs (2–3 mV), 60 dB for medium-output MCs (0.4–0.6 mV), 68 dB for low-output MCs (0.25–0.4 mV), and 73 dB for very low-output MCs (0.05–0.25 mV). Independent measurements suggest these figures are slightly understated, providing in practice a bit more gain than specified.

Resistive loading options include 33 Ω, 100 Ω, 430 Ω, 1 kΩ, and 47 kΩ, covering the needs of nearly all cartridges on the market. Input capacitance is fixed at 100 pF in all positions, which may limit fine-tuning of the high-frequency response for certain specific MM cartridges.

Settings are adjusted via DIP switches located underneath the unit, behind a magnetic cover. Michell provides a dedicated tool to facilitate operation of these tiny switches, and the options are silk-screened directly on the base of the unit in a contrasting color for easy reading. Connectivity remains basic but high quality: two pairs of unbalanced RCA sockets for input and output, plus a solid ground post. No balanced XLR output is provided, as the Apollo is designed to integrate into home systems rather than professional setups.

Frequently asked questions

Can the Apollo work with all turntables on the market?

The Apollo is compatible with all turntables equipped with MM or MC cartridges thanks to its five gain levels and multiple loading options. The exceptionally wide gain range (40 to 73 dB) accommodates even very low-output MC cartridges under 0.1 mV. Only certain MM cartridges requiring precise input capacitance adjustment might not find an optimal setting, as capacitance is fixed at 100 pF.

What’s the difference between the Apollo and older Michell phono preamps like the Delphini?

The Apollo represents a major evolution over the 2001 Delphini. The circuits use modern, latest-generation components, notably the THAT and Burr-Brown operational amplifiers absent from the Delphini. The machined solid aluminum construction replaces the Delphini’s simpler chassis, and the physical separation of the power supply into the Muse enclosure improves isolation from interference. Gain capabilities are also expanded, with a maximum of 73 dB versus 60 dB for the Delphini.

How are the gain and loading parameters adjusted?

Settings are made via four groups of DIP switches accessible underneath the unit. A magnetic cover protects these switches while allowing easy access. Michell provides a small tool to operate the switches, and the combinations are clearly indicated on the base of the unit. The process typically takes less than five minutes during initial setup.

Technical specifications

Audio performance

• High-fidelity sound: class A gain stages for clear, natural sound
• Ultra-precise RIAA curve: ± 0.1 dB from 20 Hz to 20 kHz
• MUSE power supply: low-noise toroidal transformer, dual filtering, and precision regulation
• Hand-matched components for perfect left/right balance
• Solid aluminum chassis: shields against RF interference and reduces vibrations

Gain and loading configurations

• Available gains:
  • MM: 5 mV+ / 40 dB
  • MM Low: 2–3 mV / 50 dB
  • MC: 0.4–0.6 mV / 60 dB
  • MC Low: 0.25–0.4 mV / 68 dB
  • Ultra-low MC: 0.05–0.25 mV / 73 dB
• Available loads:
  • Resistances: 47 kΩ, 33 Ω, 100 Ω, 430 Ω, 1 kΩ
  • Input capacitance: 100 pF (all loads)

Technical specifications

• THD: < 0.01%
• THD+N: -104 dB
• SINAD: > 104 dB
• Mains power: 100–240 V (50 / 60 Hz)
• DC voltage: +24 V & -24 V
• Power consumption: 5 W

Dimensions and weight

• Each unit: 115 x 280 x 60 mm
• Total weight (2 units): 3 kg
• Packaging: 480 x 400 x 110 mm
• Shipping weight: 4.7 kg

Connectivity and cabling

• Silver-plated OFC copper conductors
• FEP insulation + high-density shielding
• ChorAlloy-plated XLR connectors for perfect signal integrity