PrimaLuna EVO 400 Tube Power Amplifier

Overview

The PrimaLuna EVO 400 Tube Power Amplifier brings the storied warmth of vacuum tubes together with the flexibility serious listeners crave. Built around a push pull EL34 output stage, it delivers 70 watts per channel in stereo and can be switched to mono for 140 watts, giving you real room to grow your system. This is an amplifier designed to be lived with, engineered in Holland and built with a level of parts quality that punches far above its class.

What sets the EVO 400 apart is its remote controlled triode and ultralinear switching. Triode mode offers a warmer, fuller, easy to settle into sound, while ultralinear opens up extension at the top and bottom with greater dynamic swing and power. You can toggle between the two from your seat and choose what suits each recording, all without stopping the music. Adaptive AutoBias keeps the tubes running in their sweet spot automatically, and the Bad Tube Indicator makes ownership genuinely worry free.

Inside you will find point to point wiring with premium Swiss wire, Takman resistors, wide bandwidth output transformers, and a potted toroidal power transformer. The result is a quiet, textured, dimensional presentation with the kind of air and resonance that keeps you listening long into the night. At All Elite Audio we consider the EVO 400 one of the finest ways to bring tube magic to a high efficiency loudspeaker.

Key Features

• EL34 Push Pull Output. Eight EL34 tubes in a push pull configuration deliver 70 watts per channel in stereo, with the warmth and body that make EL34 designs so beloved among tube enthusiasts.
• Remote Triode / Ultralinear Switching. Toggle between the warmer, fuller triode voice and the more extended, dynamic ultralinear mode from the supplied remote, choosing the character that suits each recording without leaving your chair.
• Stereo or Mono Operation. Run the EVO 400 as a stereo amplifier at 70 watts per channel, or switch a pair to mono for 140 watts each, giving you a clear upgrade path within a single chassis design.
• Adaptive AutoBias with Bad Tube Indicator. AutoBias keeps every tube in its optimal operating range automatically. If a tube fails, the amp enters protection mode and a red LED lights in front of the tube to replace, no soldering or guesswork required.
• Point to Point Wiring and Premium Parts. Hand wired point to point with premium Swiss wire and Takman resistors, the EVO 400 uses parts you would normally pay a premium to add to a lesser amplifier.
• Custom Wound Transformers. Wide bandwidth output transformers and a potted toroidal power transformer provide low noise, deep bass authority, and the sense of space that tube lovers chase.
• Flexible Connectivity. Both RCA and XLR inputs in stereo and mono, plus 4, 8, and 16 ohm taps in stereo, make the EVO 400 easy to integrate with a wide range of preamplifiers and speakers.

How the PrimaLuna EVO 400 Tube Power Amplifier Compares

PrimaLuna EVO 400 Tube vs Parasound JC5 Stereo Power Amp

The JC5 is a high current solid state stereo amplifier with tremendous grip and control. Where it leans toward precision and effortless power into demanding loads, the EVO 400 offers the harmonic richness and dimensionality of tubes with the flexibility of triode and ultralinear voicing.

PrimaLuna EVO 400 Tube vs Parasound JCM250 Monoblock

The JCM250 monoblocks deliver dedicated single channel solid state power with a clean, dynamic character. The EVO 400 answers with a tube presentation you can shape between warm triode and lively ultralinear, and it too can move to mono when you want more headroom.

PrimaLuna EVO 400 Tube vs Advance Paris X-A600 Stereo Amplifier

The X-A600 is a muscular stereo amplifier for driving a broad range of speakers with authority. The EVO 400 takes a different path, pairing its 70 watts with the texture and air of vacuum tubes, an ideal match for efficient loudspeakers.

PrimaLuna EVO 400 Tube vs Advance Paris X-A1200 Mono Amplifier

The X-A1200 monoblocks are about raw solid state power and scale. The EVO 400 focuses instead on tone and involvement, delivering tube warmth with switchable triode and ultralinear modes and the option to run in mono itself.

PrimaLuna EVO 400 vs PrimaLuna EVO 300 (next step down)

The EVO 300 is a more compact option that keeps triode, ultralinear, and XLR inputs but uses four EL34 for 44 watts per channel in stereo instead of eight EL34 for 70.

Recommended Speakers

The EVO 400's 70 tube watts sing brightest with high efficiency loudspeakers, and Klipsch Heritage is the natural first stop for tube synergy. These picks all reward the amplifier's warmth and dynamics.

• Klipsch Forte IV: A superb match for the EVO 400. The Forte IV's high efficiency lets the amplifier's tube character shine with effortless dynamics and lifelike presence.
• Klipsch Cornwall IV: The Cornwall IV pairs big, room filling sound with easy efficiency, making the most of the EVO 400's triode and ultralinear voicing.
• Klipsch La Scala AL6: A horn loaded classic that thrives on quality tube watts. With the EVO 400 the La Scala AL6 delivers immediacy and scale in equal measure.
• Klipsch Heresy IV: Compact yet highly efficient, the Heresy IV is an ideal way to enjoy the EVO 400 in a moderately sized room with plenty of tube warmth.
• Klipsch RF-7 III: The RF-7 III's high sensitivity and dynamic horn tweeter respond beautifully to tube power, making it a lively, engaging partner for the EVO 400.

Frequently Asked Questions

How much power does the EVO 400 produce?

In stereo the EVO 400 delivers 70 watts per channel. Switched to mono, each unit produces 140 watts, so a pair gives you significantly more headroom.

What tubes does the EVO 400 use?

It uses six 12AU7 driver tubes and eight EL34 power tubes. The EL34 push pull output stage is central to its warm, musical character.

What is the difference between triode and ultralinear mode?

Triode mode is warmer, fuller, and easy to settle into, while ultralinear offers more top and bottom extension, greater power, and bigger dynamic swings. You choose based on the recording and your taste.

Can I switch between triode and ultralinear while listening?

Yes. The supplied remote lets you toggle between the two modes on the fly, so you can compare and pick what you prefer without stopping the music.

Can the EVO 400 be run as a monoblock?

Yes. The amplifier is switchable between stereo and mono operation. In mono it delivers 140 watts, and using two units gives you a full monoblock system.

What is Adaptive AutoBias?

Adaptive AutoBias continuously keeps each tube biased in its optimal operating range. It removes the need for manual biasing and helps extend tube life.

What happens if a tube fails?

If a tube fails, the amplifier enters protection mode to prevent damage, and a red LED lights in front of the tube that needs replacing. You simply swap in a new tube and continue listening.

Do I need to bias the tubes manually?

No. AutoBias handles biasing automatically, which is one of the reasons the EVO 400 is so easy to own and maintain.

What speaker impedances does it support?

In stereo the EVO 400 provides 4, 8, and 16 ohm output taps. In mono it offers 2, 4, and 8 ohm taps, so you can match it precisely to your speakers.

Does it have balanced inputs?

Yes. The EVO 400 accepts both RCA and XLR inputs in stereo and mono configurations, so it integrates easily with balanced and single ended preamplifiers.

What is the input impedance?

The input impedance is 100 kohm, which makes the EVO 400 an easy load for a wide range of preamplifiers.

What kind of speakers pair best with the EVO 400?

High efficiency loudspeakers are ideal. Klipsch Heritage models like the Forte IV, Cornwall IV, and La Scala AL6 make the most of the EVO 400's tube character and 70 watts.

How is the EVO 400 built internally?

It uses point to point wiring with premium Swiss wire, Takman resistors, wide bandwidth output transformers, and a potted toroidal power transformer for low noise and rich, dimensional sound.

What is the AC Offset Killer?

It is a PrimaLuna circuit designed to lower transformer noise regardless of the quality of your household electricity, contributing to a quieter background and greater sense of space.

What finishes are available?

The EVO 400 is offered in Silver and Black. We can help you confirm current availability at All Elite Audio.

How heavy is the EVO 400?

Each unit weighs 68.2 pounds, reflecting the substantial transformers and robust construction inside.

What are the dimensions?

The EVO 400 measures 15.2 inches wide, 8.1 inches high, and 15.9 inches deep. Allow additional clearance above for ventilation and the tube cage.

Is a tube power amp difficult to live with?

Not with the EVO 400. AutoBias, the Bad Tube Indicator, and protection circuitry make it about as easy to own as a tube amplifier can be. We are happy to walk you through the basics.

Can I roll tubes in the EVO 400?

Yes, many owners enjoy experimenting with different tubes to tailor the sound. AutoBias makes this straightforward. Our team can advise on suitable options for your goals.

Why buy from All Elite Audio?

All Elite Audio is an authorized PrimaLuna dealer in Maryland. That means genuine product, full manufacturer warranty support, and expert guidance on pairing the EVO 400 with the right speakers and preamplifier. We audition, deliver, and support what we sell so you can buy with confidence.