Aries Cerat · Integrated Amplifier

Protos

A single-stage, single-ended integrated amplifier featuring proprietary TriodeFet technology.

In audio electronics, circuit simplicity is widely considered the ultimate virtue, yet it is rarely pursued to its absolute extreme. The Aries Cerat Protos shatters conventional amplifier design by achieving a truly single-stage architecture. Within this integrated amplifier, there is no input stage and no driver stage—merely one continuous amplification phase from the source input to the loudspeaker. Serving as a gateway into the advanced Ianus series, the Protos inherits its fundamental DNA from the flagship Aperio. It accomplishes its single-stage feat through the brand’s proprietary TriodeFet technology. This unique active element possesses the extremely high linearity, voltage gain, and input impedance necessary to manage the entire signal path alone, yielding 20 watts of pure Class A power. Sonically, the Protos delivers the holographic midrange, accurate timbre, and vast soundstage traditionally associated with the finest single-ended triode designs, yet it operates entirely free from the limitations of big-bottle output tubes. It exerts profound control over the loudspeaker, offering tremendous tonal weight, organic flow, and a startling level of transparency that only a pure single-stage circuit can provide.

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Key Features

Single-Stage Topology

From the RCA inputs to the speaker posts, the Protos employs only one stage of amplification. By eliminating driver and input stages entirely, it achieves the elusive goal of absolute circuit simplicity.

TriodeFet Technology

Utilises proprietary active elements that mirror the transfer curves of an ideal vacuum tube. This provides the necessary voltage and current gain for a single-stage design alongside a maintenance-free 10,000-hour lifespan.

R2R Volume Attenuation

Volume is strictly controlled via a 61-step relay-switched resistor ladder. This array bypasses the degradation of standard potentiometers and can be disabled on the fly for use with a separate preamplifier.

Direct-Drive Headphone Output

Features a front-panel 4-pin XLR headphone output that is directly driven by the main output stage. It delivers the amplifier's full 20-watt output to headphones without requiring complex impedance matching.

External Power Supply

The transformers and soft-start mechanisms are housed in a dedicated external chassis. This completely isolates the sensitive single-stage circuit from electromagnetic interference and mechanical vibration.

Chapter 01

Design & Philosophy

The Ianus Protos began as an engineering exercise to determine how minimal a circuit could be whilst utilising Aries Cerat's larger TriodeFet architecture. Dictated by the principles of minimum complexity, the result is a product that completely abandons conventional multi-stage topologies. There is no pre-amplification stage and no driver stage—simply one uninterrupted path from source to speaker. By removing these supplementary gain stages, the amplifier eradicates the cumulative distortion and phase shifts that inevitably plague complex circuits.

Chapter 02

TriodeFet Architecture

Traditional single-ended triode amplifiers rely on large output tubes that require frequent replacement and careful maintenance. The Protos bypasses this entirely through TriodeFet technology. By using internal tubes strictly for transfer curve creation, the active element operates with the transfer characteristics of an ideal triode whilst delivering the stability and current drive of solid-state components. Because the internal vacuum tubes are not subjected to the strenuous loads of driving loudspeakers directly, they achieve lifespans exceeding 10,000 hours. The result is the sonic purity of a triode valve without the associated thermal and mechanical fragility.

Chapter 03

Sonic Signature

Because it places only a single amplification stage in the signal path, the Protos possesses an incredibly low noise floor and staggering transparency. It delivers the hallmark traits of elite tube amplification, presenting a deeply textured midrange, natural acoustic decay, and a massive, holographic soundstage. Crucially, it backs this refinement with 20 watts of pure Class A power, offering absolute grip and an unflinching, visceral presentation. It exerts profound control over the loudspeaker, ensuring that dynamic shifts are rendered with physical impact and effortless speed.

Specifications

TechnologySingle-stage, single-ended TriodeFet integrated amplifier

Gain stagesSingle stage from input to output posts

Power output20W @ 8 ohms

Power bandwidthFull power at 5Hz to -3dB

Maximum gain18dB (tube dependent)

Noise floor-90dB ref 1V RMS

Tube complement2 x 6j11p-e (compatible with E280F, E282F, E810F, E180F, D3A)

Volume control61-step relay-switched resistor ladder

Inputs5 x RCA

Headphone output4-pin XLR, directly driven by output stage (no impedance matching required)

Dimensions (H × W × D)Main unit: 170 × 500 × 490 mm / PSU: 70 × 190 × 310 mm

WeightMain unit: 60 kg / PSU: 5 kg

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