Atoll IN400 Integrated Amp, $7000 (160×2)

{5.11h, 17.32w, 14.17d, 43 lbs}

Atoll’s IN400 is a true contender for state of the art integrated amp! I say that without reservation. IN400 is right there with the best of the best, regardless of price.

IN400 runs $7k in line stage configuration. Add $320 for the DA100 DAC board and $130 for the P50 MM phono preamp board. Build your own pizza, or run line stage as is for $7k.

If we were to blindfold you in your chair and do an A-B comparison with a myriad of price no object integrateds, IN400 would win in many categories of aural performance. Considering its state of the art competitors run $20-30k on up, IN400 is the best purchase option of the bunch. In fact, most integrateds at this price point are built in Chinese job houses with Euro names on them. Sheeze!

Atoll is built in Atoll’s factory in France with a three year warranty. It isn’t designed in France and built in China. Some companies that contract Chinese vendors to build for them put “France” on the back panel, which is different from “Made in France.”

Nor is Atoll a pile of Chinese parts assembled in France to try to fake you out with a label that says “Assembled in France.”

Atoll is an honest to gosh, family owned company in a day and age where most of its competitors are subsections of hedge funds. Atoll delivers a level of TLC that the other guys simply can’t.

Power Supply

The heart of IN400 is its power supply. It starts with a ginormous 1050VA transformer that Atoll has designed and has built for them in Spain. It is an internal dual mono structure. It has separate windings for each channel. It uses a second 1.6VA transformer for control logic.

The filter caps are also designed by Atoll and are custom built for them in Japan. IN400 uses almost 100,000uF in power supply caps to help deliver a rich and weighty musical character.

Chassis

IN400 is mechanically stout. Its face plate is just under one half inch of micro-blasted and anodized aluminum, with high precision engraving. The chassis is made of steel. Heat sinks are machined aluminum construction.

Matched Output Transistors

IN400 runs 8, MATCHED MOSFET output transistors per channel. This is a vital part of Atoll’s TLC. Imagine you have a tuning fork tuned to middle C. Then you add another and play them simultaneously. If they’re not precisely the same- you incur distortion artifacts.

Relay this analogy to an amplifier’s performance. If you run, in this case, 16 output transistors, all buzzing away at their own whim, you’re guaranteed to get grainy results. Atoll takes the time to hand match its transistors so you’ll achieve a more ebullient character in your music. This explains why, historically, higher powered amps sound more grungy than their lower powered siblings. The more power and transistors you run, the more harsh the amp will sound. Twas ever thus.

Atoll takes assiduous effort to be sure its more powerful amps are just as mellifluous as the rest of the family. You pay no penalty for greater horse power with Atoll. With virtually everyone else, the bigger they are, the harder they…. Sound.

Open/Airy Presentation

With this long-winded preface behind us… it is in a singer’s voice that IN400 first grabs me. Toss on a buoyant singer with acoustic guitar (Joan Armatrading “Love & Affection”) and be prepared to hear resolution and ambiance galore. Joan’s breathy delivery is a thrill to hear! Plenty of amps will play this “cleanly.” But to imbue the soundstage in front of you with so much space and air takes on ethereal beauty. It made me think of fireplace bellows of massive capacity vs flimsy ones. Run through a variety of great speakers (Bryston, Magnepan, Atohm) I know very well, they all sounded more capacious with IN400 than anything equal or less money.

IN400 delivers this lovely level of open/airy sound- without adding a hint of BRIGHTNESS up top. This weighs heavily in my recommendation of Atoll. We get the spacious soundstage without a sharp high end.

It would be absolutely fair to say IN400 will please any tube lover with its tonality. You’ll derive this warm fluidity and 3D soundstage without the heat, hassle and noise endemic to tubes.

IN400 has a muscular low end- much weightier and more convincing than any D designs. It’s more powerful and controlled than any tube amp. Its balance is hefty and impactful which will allow any speaker to reach its max level of effulgence.

While no amp is perfect, we’re always looking for the best performance we can achieve at a given price point. What makes IN400 my fave is that it curates the MOST IMPORTANT vocal region (whether humans, pianos, acoustic instruments) better than any integrated I’ve heard.

IN400 does this without a crispy top end or thin bass response. I don’t want tubes with their heat, noise, sluggish bass and poor reliability. IN400 is a ground breaking integrated at an attainable price for people (like us!) who value singers, pianos and the sound of exquisitely crafted acoustic instruments.

IN400 Deserves The Best Speakers

As I’ve gotten to know IN400 well, its strength is in bringing more air, space and weight to great speakers like Atohm GT3s, Bryston T Series and Magnepan MG 2.7i.

When you listen to speakers a notch down from these, it’s fair to say IN300 brings 95% out of them. It wouldn’t be a waste to run IN400 with this echelon of speaker. But IN400 is a step higher than what the Bryston As or Maggies (without true ribbon tweets) need.

I have a few words to say about Atoll’s implementation of its Burr Brown DACs. The DAC performance of IN400 with the DA100 board installed, is clean yet smooth. Atoll runs the Burr Browns without negative feedback. Please be aware that the latest greatest chipsets that brag up higher processing power, universally sound brighter and leaner than how BB performs within Atoll. More processing doesn’t yield a more musical sound, any more than cranking up the contrast control makes a TV look better.

IN400 earns its space with the most revealing speakers you can get. Ifp you have top tier speakers or are planning to get some down the road, IN400 is right up your alley.