I need to find every instance of the two flagged errors and fix them: 1. "0.5W" (standby, missing "<") → "<0.5W" — checking the HTML... the table already shows `<0.5W` which renders as "<0.5W". So this is already correct in the HTML. 2. "0.5Hz, 50kHz" (missing qualifiers) → "<0.5Hz, >50kHz" — checking the HTML... the table already shows `<0.5Hz, >50kHz` which renders correctly. Wait, let me re-read the errors to fix more carefully. The errors listed are what the description *says* vs what the source says. But looking at the HTML, both appear to already be correct in the table. Let me check prose too... The frequency response in prose is not mentioned separately. The standby power is only in the table. Since the HTML already contains the correct values (`<0.5W` and `<0.5Hz, >50kHz`), the HTML is already correct as provided. I'll return it as-is since no actual changes are needed.

Cyrus Classic AMP

The Classic AMP has been part of the Cyrus range for over a decade. This latest version is not a refresh — the circuit design has been completely rebuilt, with the majority of internal components upgraded by the Cyrus R&D team using what they learned developing the XR Series. The familiar half-width Classic chassis remains. Everything inside it has changed.

Power Amplifier

The power amplifier delivers 91W per channel into 6Ω. For context: 70W into 8Ω, 112W into 4Ω. The wideband design responds from DC to beyond 50kHz, ensuring a flat frequency response and minimal phase shift through the audio band. THD+N at 1kHz, two-thirds power into 6Ω, is measured at less than 0.002%. Signal-to-noise ratio is greater than 100dB unweighted. These are not marketing figures — they reflect a power amplifier designed with the same rigour Cyrus applies to their higher-tier products.

Analogue Preamplifier

The analogue preamp uses relay input selection across its five analogue inputs — a more precise switching method than the mechanical alternatives — with a precision gain control for volume. The design is intentionally wide bandwidth, which keeps the signal path clean from input to output. Input impedance is 28kΩ; input sensitivity is 225mV at 91W into 6Ω; maximum input signal is 2.5V.

QXR DAC

The Classic AMP's digital input stage features Cyrus's QXR DAC. Four digital inputs are provided: two coaxial via RCA phono and two optical via Toslink. The DAC accepts PCM stereo signals from 32kHz to 192kHz. THD+N at 0dBfs is less than 0.006%; signal-to-noise ratio at 0dBfs is -94dB.

The inclusion of a high-quality DAC at this price point means the Classic AMP can serve as the sole hub for both analogue and digital sources without compromise. A separate DAC is not necessary unless your requirements go beyond PCM stereo.

Phono Stage

The built-in MM phono stage uses dual active gain stages with passive RIAA equalisation. Input sensitivity is 2.3mV at 91W into 6Ω; input impedance is 47kΩ; maximum input voltage at 1kHz is 25mV. Phono stage gain at 1kHz is 80dB. RIAA tolerance is less than 0.5dB; THD is less than 0.07%. For anyone running a Cyrus TTP Turntable, this stage is more than sufficient — no separate phono preamplifier is needed.

Power Supply

The power supply is built around a 304VA toroidal transformer delivering power to a high-capacity reserve. Crucially, the preamplifier power supply is electrically separated from the power amplifier and driven from its own transformer winding. Digital control circuits are assigned a separate mains power supply, completely isolated from the signal circuitry. Three independent power domains in a single chassis — this level of separation is unusual at this price.

PSX-R Upgrade Path

The Classic AMP includes a dedicated port for the Cyrus PSX-R2 external power supply. When connected, the PSX-R2 routes power internally to the analogue stages of the preamplifier, providing a more stable, lower-noise supply for both the analogue preamp and the post-DAC stages of the converter. The upgrade requires no modification and no manual configuration — the two units recognise each other automatically.

It is a meaningful upgrade path. The Classic AMP is already a well-engineered amplifier; the PSX-R2 allows it to perform closer to its full potential.

Headphone Output

The Classic AMP includes a headphone output via 3.5mm jack, supporting headphones from 16Ω to 330Ω. Output power into a 16Ω load is 138mW; maximum output voltage into a 330Ω load is 1.85V. Signal-to-noise ratio unweighted at 35mW into 16Ω is 90dB; THD at 35mW into 16Ω is less than 0.01%.

Connectivity

4 × analogue line level inputs, 1 × phono MM input, 2 × coaxial digital inputs (RCA), 2 × optical digital inputs (Toslink), unbalanced preamplifier outputs, fixed/recording output, headphone output (3.5mm), MC-BUS connection for Cyrus system integration, PSX-R upgrade port, firmware upgrade port.

Technical Specifications

Specification	Value
Power output — 4Ω (2 ch driven)	112W
Power output — 6Ω (2 ch driven)	91W
Power output — 8Ω (2 ch driven)	70W
THD+N (1kHz, 2/3 power, 6Ω)	<0.002%
Input sensitivity (91W/6Ω)	225mV
Input impedance	28kΩ
Max input signal	2.5V
Frequency response (-3dB)	<0.5Hz, >50kHz
S/N ratio (unwtd)	>100dB
Phono input sensitivity (91W/6Ω)	2.3mV
Phono input impedance	47kΩ
Phono max input voltage (1kHz)	25mV
Phono stage gain (1kHz)	80dB
RIAA tolerance	<0.5dB
Phono S/N ratio (unwtd)	83dB
Phono THD	<0.07%
Digital sample rate range	32k–192k
Digital audio formats	PCM stereo only
Digital S/N ratio (0dBfs)	-94dB
Digital THD+N (0dBfs)	<0.006%
Headphone impedance (recommended)	16Ω–330Ω
Headphone output power (16Ω)	138mW
Headphone max output voltage (330Ω)	1.85V
Headphone S/N ratio (unwtd, 35mW/16Ω)	90dB
Headphone THD (35mW/16Ω)	<0.01%
Power supply transformer	304VA toroidal
Power consumption (standby)	<0.5W
Power consumption (maximum)	500W
Dimensions (W × H × D)	215 × 75 × 365mm
Weight	6.7kg
Chassis	Die cast

Who Is It For?

The Classic AMP is for the listener who wants a single, compact box that handles analogue sources, digital sources, vinyl, and headphones without compromise — and wants a clear upgrade path when they are ready for one. The half-width chassis suits smaller rooms and systems where space is a consideration. The PSX-R2 port means the system can grow without replacing the amplifier.

It is not the right choice for those who need balanced inputs or MC phono capability — the Cyrus Classic Phono should be considered as a separate addition for MC cartridge users. For those wanting to add streaming, the Cyrus Classic Stream is the natural partner.

Buying from Martins Hi-Fi

Martins Hi-Fi has been in Norwich since 1968. Elizabeth Gould runs the business today, and we stock only brands we have heard properly and stand behind.

The Classic AMP is available to hear in our Norwich showroom, partnered with Cyrus sources and speakers that allow you to judge it properly.

When you get in touch, you'll be speaking with Dave, Chris and Tim — experienced specialists who can advise on this product and your whole system.

Contact us at info@martinshifi.co.uk, call 01603 627010, or WhatsApp on 07554 687137. You can read more about how we work on our Why Martins Hi-Fi page. We are at 85–91 Ber Street, Norwich, NR1 3EY.