Rothwell · Rothwell Phonos
Iridium valve phonostage
Classic valve architecture refined for modern high-resolution analogue playback.
The Iridium stands as a mature evolution of Rothwell's valve design heritage, which began with their first prototypes in the 1980s. By focusing exclusively on moving magnet performance, the design allows for an uncompromising approach to signal amplification and equalisation.
At the core of the Iridium are ECC83 valves, selected for their stability and proven performance in small-signal audio applications. The circuit eschews global feedback entirely, opting instead for a minimalist, passive RIAA network constructed with high-grade polypropylene capacitors and precision resistors to maintain absolute signal integrity.
Rather than imposing the traditional soft warmth often attributed to valves, the Iridium is engineered for transparency and detail. It unravels complex musical passages with ease, providing an expansive soundstage and a sense of acoustic scale that allows the listener to engage deeply with the original recording environment.
Key Features
01
ECC83 valve gain stages
Selected for their stability and long-established performance in small-signal audio circuits.
02
Passive RIAA equalisation
Utilises high-grade polypropylene capacitors and precision resistors to ensure accurate frequency response.
03
Regulated heater supply
A dedicated DC supply for valve heaters effectively eliminates low-level hum and noise.
04
Zero global feedback
The circuit design avoids global feedback to maintain a natural, non-fatiguing musical presentation.
05
Advanced power filtering
Multi-stage high-voltage filtering and independent channel networks minimise crosstalk and ripple.
Chapter 01
Design & Philosophy
The Iridium represents a commitment to the art of valve amplification, rooted in over thirty years of development. By choosing a valve-based architecture for moving magnet cartridges, the design avoids the typical pitfalls of integrated solid-state solutions, favouring a direct, transparent signal path that prioritises natural textures over technical artifice.
Chapter 02
Build & Materials
Constructed to reflect its high-end positioning, the Iridium employs heavy-duty internal filtering and solid-core silver-plated OFC internal wiring with PTFE insulation. The build quality reflects a focus on longevity and mechanical stability, ensuring the delicate valve stage remains isolated from both internal and external interference.
Chapter 03
Sonic Signature
The Iridium is prized for its ability to balance musical fluidity with high-resolution detail. It avoids the additive colouration sometimes found in valve designs, instead offering a clean, open window into the performance where instrumental layers remain distinct and the acoustic atmosphere of the studio is preserved with satisfying realism.