Swiss manufacturer Nagra has expanded its Series II electronics line with the AMP II-S, a stereo power amplifier designed as the natural partner to the recently introduced PREAMP II-S. The Nagra AMP II-S succeeds the Classic AMP, introduced in 2015, and carries forward its natural tonal balance and effortless dynamics while adding more than a decade of engineering gained from Nagra’s HD and Reference electronics.
What Changed Inside the Nagra AMP II-S
Nagra’s engineers revisited every stage of the amplifier for the Series II update, from the power supply and input stage through PCB layout, thermal management and mechanical construction. The Nagra AMP II-S is built around a new linear power-supply architecture with a custom 800VA potted transformer, suspended to absorb 99 percent of vibration between 50 and 100Hz and tuned separately for different mains voltages. A new input board, derived from Nagra’s Reference AMP, improves left/right channel separation for more precise imaging, while hand-wiring from input stage to power stage and new internal cabling are both aimed at greater transparency. The result builds directly on the engineering introduced with the Nagra PREAMP II-S, the preamplifier that opened the Series II line earlier this year.
Power, Topology and Build
Each channel of the Nagra AMP II-S delivers 120W RMS into 8 ohms in Class AB, with 10W running in Class A for the first watts of output. A single pair of MOSFET transistors per channel keeps the signal path simple, and increased rail voltage adds headroom for transient peaks. The amplifier sits on a massive CNC-machined heatsink chosen to minimise unwanted vibration while providing thermal inertia, and optically isolated controls on the front panel keep electrical noise away from the audio circuitry.
A Partner for the PREAMP II-S
Nagra designed the AMP II-S to pair directly with the PREAMP II-S, the preamplifier that opened the Series II line between the brand’s Compact and HD ranges. Together, the two components give Nagra a complete Series II electronics chain positioned to sit at the heart of a high-end system without stepping up to the costlier HD or Reference ranges.
Pricing and availability
The Nagra AMP II-S is listed at AUD 33,995 through Australian dealer Audio Connection, available to pre-order with an estimated lead time of 12 to 16 weeks; pricing in other markets should be confirmed with local Nagra dealers.
Key specifications
- Power output: 120W RMS per channel into 8Ω (10W Class A)
- Class: AB
- Bandwidth: <10Hz to 75kHz, +0/-3dB
- Signal-to-noise ratio: 110dB (typical, ASA A-weighted)
- Crosstalk: >90dB
- THD+N: <0.05% at 120W
- Dimensions: 461 x 280 x 174mm
- Weight: 24.5kg
