PrimaLuna has introduced the EVO 400, a flagship tube integrated amplifier built around point-to-point wiring, custom-designed transformers, and the brand’s Adaptive Auto Bias circuit. The PrimaLuna EVO 400 is designed to make tube ownership approachable, automating the maintenance that traditionally keeps buyers away from valve amplification while still delivering the three-dimensional, tactile sound tube fans expect.
Craftsmanship and Protection Circuitry
Every PrimaLuna EVO 400 is hand-assembled, with a heavy-gauge, fully vented steel chassis finished in five hand-rubbed and polished coats. Inside, point-to-point wiring uses Swiss silver wire, and custom-designed toroidal and EI-frame transformers are fully encapsulated for low hum and strong isolation. PrimaLuna’s SoftStart circuit extends component life and reduces the chance of thermal shock to the tubes at power-up, while an improved output-stage protection circuit uses a relay to shield the output transformers, resistors, and high-voltage power supply in the event of a catastrophic tube failure. A PTP (Power Transformer Protection) circuit adds a thermal switch that opens the primary circuit if the transformer overheats, then automatically restores power once it cools.
PrimaLuna EVO 400 Adaptive Auto Bias and Tube Rolling
The PrimaLuna EVO 400 carries the brand’s exclusive Adaptive Auto Bias circuit, which sits outside the signal path and continuously monitors and adjusts tube bias, cutting maintenance and distortion alike. Owners who want to experiment with tube rolling can switch between EL34, KT88, KT120, and KT150 output tubes using a high/low bias switch, without the jeweler’s screwdrivers and multimeters other tube-amp makers require. In Ultra-Linear mode, the amplifier delivers 70 to 88 watts per channel depending on the tube type, or 38 to 50 watts per channel in Triode mode. An optional internal PhonoLogue moving-magnet phono stage can be fitted in its own shielded box on the bottom plate, fully isolated from the rest of the circuit.
Connectivity and Everyday Details
Around back, the PrimaLuna EVO 400 offers five pairs of stereo RCA inputs plus a dedicated home theater input, along with 4 and 8 ohm speaker taps, tape output, a stereo/mono subwoofer output, and a headphone jack. A heavy metal remote control replaces the flimsy plastic units common at this price point, and small details, like an aluminum screw marking the live side of the AC input, reflect PrimaLuna’s focus on everyday usability. Read more about accessible tube amplification in our coverage of the Lab 12 Might tube amplifier.
Pricing and availability
The PrimaLuna EVO 400 tube integrated amplifier is priced at $6,495 and is available now in black or silver finishes through PrimaLuna’s official product page and its dealer network.
Key specifications
- Model: EVO 400-1, for EL34 / KT88 / KT120 / KT150
- Power Ultra-Linear: 70 / 72 / 85 / 88 watts per channel
- Power Triode: 38 / 40 / 45 / 50 watts per channel
- Frequency response: 9 Hz to 50 kHz +/- 1 dB
- THD with AABB: less than 0.1% at 1W, less than 2% at rated power
- Signal-to-noise ratio: 90 to 98 dB A-weighted
- Inputs: 5 pairs stereo RCA, 1 home theater input
- Outputs: 4 and 8 ohm speaker taps, tape, stereo/mono sub, headphone
- Tube complement: 8x EL34, 6x 12AU7
- Weight: 31 kg net / 36 kg shipping
- Dimensions: 405 x 385 x 205 mm (L x W x H)
- Price: $6,495
