The Norman electronics manufacturer officially unveiled its new integrated amplifier at the Festival du Son et de l’Image last October at the Pullman Paris Tour Eiffel hotel. This is the IN300, the prototype of which we were able to discover in Munich in May 2016. From its name alone, it’s easy to imagine that it stands between the IN200SE, with its many years of excellent and loyal service to audiophiles, and the IN400SE, the flagship of the Brécey workshops. A glance at the data sheet confirms this positioning in the Atoll integrated range. But beyond a very popular appearance, appreciated by Atoll’s first generation of audiophiles, there are more marked similarities with the 400 series.
The two control buttons on the front panel of the IN300 bring it functionally closer to the IN400 than to other INs. The oblong window of the central display is identical to that of the big brother. A glance at the rear also reveals the presence of digital inputs, indicating the standard installation of a DAC converter, as on the IN400. The IN300 is therefore more like a small IN400, as Stéphane Dubreuil confirmed during the presentation of the device at the Son et Image festival, a device concentrating all Atoll’s know-how at a price that places it midway between the 200 and 400. The integrated range is now completely balanced, with the 300 closing the gap that had opened up between the 200 and 400.
An accessible high-end spirit
You may have already noticed that the technical specifications of the IN 300 are quite similar to those of the 400, and you’re thinking, after all, why invest in a 400 when the 300 does basically the same thing? The nuance is in the “overall”. And we know the Atoll team and their design philosophy well enough not to have imagined for a second that they could design electronics that would outrageously overshadow another model in the range. At Atoll, there’s a precise place for every product reference, and the IN300 fits between the 200 and 400 without rendering obsolete. In terms of circuit topology, all Atoll’s technological attributes have been carried over to the IN300, which also benefits from certain advances introduced in the IN400SE. The symmetrical layout develops 150 W at 8 ohms per channel and around 260 W at 4 ohms from a triple push-pull output stage with Mos-Fet transistors. By way of comparison, the 400 with its quadruple push-pull power output reaches 160 and 300 W at 8 and 4 ohms respectively. We’re working on a similar energy basis, with class AB biasing at a sufficiently high quiescent current to deliver the first ten or so watts in class A. The circuit layout is a melting pot of what has already been done on the IN200 and IN400. The manufacturer has installed two toroidal transformers of over 440 VA each to supply the left and right channels independently. This is the best way to achieve optimum channel separation and lower crosstalk. Capacitive filtering exceeds 86,000 uF in a configuration of twelve electrochemical capacitors with very low ESR (equivalent series resistance), like that of the IN400. These models are manufactured to Atoll’s exclusive specifications. A shielded cable developed by Absolue Créations carries the mains from the IEC socket to the transformers, with a clear audible difference from lambda cable. As for the power transistors, they are mounted one by one on independent finned heatsinks, a technique derived from the IN200 that increases cooling efficiency and lowers cost compared to a traditional heatsink on which all the transistors would have been mounted.
As in all the manufacturer’s other models, the IN300 is reserved exclusively for discrete components. Two boards compete for circuit space, the main one grouping all analog audio as a power supply, and a second board attached to the back of the digital inputs, which is none other than the digital-to-analog conversion board. All stages upstream of the output stage are polarized in pure Class A, with a reduced overall negative feedback rate. Mundorf’s polypropylene-film link capacitors are concealed under metal shielding covers to preserve their total immunity to interference (these capacitors are housed in metal cylinders which act as true antennas). The two orange connectors on the card stand define the location of one of the two optional plug-in phono cards. Volume control is provided by digitally switched attenuation resistors. The operation is handled by a Texas Instruments LM1972 circuit, a CMOS-technology stereo attenuator with a variable step size of 1 dB between -78 and -48 dB, then 0.5 dB between -47.5 and 0 dB. As with the dual power supply, this pure and simple separation of the volume control of the two channels considerably improves their guaranteed electrical separation of over 100 dB, and consequently the stability of the stereo image and the focus of the sound sources. The digital-to-analog conversion strategy is orchestrated by an AK4490 chip, a new-generation Asahi Kasei DAC with very high resolution. This 32-bit chip accepts PCM sampling frequencies up to 768 kHz and DSD up to 11.2 MHz. Data first passes through data receivers, a Wolfson WM8805 for S/PDIF information and a USB33 series SMSC for the USB stream, which is then routed to an XMOS chip. No less than four quartz crystals synchronize the various signals. A Roving Networks RN52 module with integrated antenna ensures Bluetooth connectivity with compatible external media.
THE SET UP
Weighing in at over fifteen kilograms, the IN300 is a heavyweight, and a suitable stand is essential. On our Centaure L, it has found a solid foundation, conducive to reconciling its powerful power section with its subtle digital stage. As far as cabling is concerned, the choice is quite open: Absolue Créations, Esprit and Furutech provided us with excellent results. The IN300 deserves a good power cord, and a longer initial warm-up time to bring its DAC up to temperature. Finally, when it comes to loudspeakers, the field is wide open, as this amplifier boasts a more than respectable power supply and a surprising reserve of power.
Over time, Atoll’s sound has blossomed naturally, achieving an undeniable balance. To put it mildly, Atoll has mastered the seductive side of neutrality. In fact, with the IN300, the Norman brand offers an amplifier with a mature, composed sound. Here’s a machine you won’t choose just for reason, but also for passion, such is its endearing character. On first listen, the fundamentals are already clear, based on a wide range of available power that expresses itself smoothly. The IN300 doesn’t try to convince: the presence it imposes on the recording is enough to be sure. We appreciate its density, full but never overloaded timbres, singing midrange and finely chiseled treble. Its strength lies in its ability to suggest real muscle, while remaining subtle. In electronic music, for example, the tension of the bass strings and the delicacy of the spatial effects in the high midrange can be perceived with accuracy. The IN300 deciphers modulation with precision, transcribing it in the clearest light! On less crystal-clear tracks, this ability to deliver a wide frequency range without a break between registers is palpable. The bass extends the high midrange with ease, without the slightest trace of drag or rupture. At the upper end of the spectrum, the IN300 delivers a freedom of expression and articulation of the highest quality. The result is a smooth, fluid listening experience, particularly in terms of sound image, where the key word seems to be “aeration”. In terms of objective qualities, the listener can’t help but be surprised by the very fine dynamic range, which confirms the ability of the power supply and analog circuits to transcribe the liveliness of any type of message.
We’ve said it many times, but Atoll is THE French electronics manufacturer today, and its range is expanding with a very good vision of the market. The Normandy-based company certainly has many successes to its credit, but with the IN300, it offers a highly musical, hyper-complete product that titillates the references in the niche. The greatest quality of these electronics remains their naturalness and their ability to make most of the files we’ve given them to work with sound good, without ever repeating themselves, and always finding the right angle, the right proportions, the perfect lighting… With the IN300, Atoll is undoubtedly one of the most musical manufacturers in this price range, offering nuanced, expressive listening that can be enjoyed for hours on end without the slightest auditory fatigue.
440 x 100 x 320 mm
2 x 150 W at 8 ohms, 2 x 260 W at 4 ohms
4 RCA line, one of which can be converted to phono with an optional card, 1 RCA bypass, 1 XLR line, 1 RCA Tape In
4 S/PDIF (2 RCA and 2 Toslink, PCM 24/192), 1 asynchronous USB-B (PCM 32/384 and DSD 128), 1 Bluetooth receiver
2 RCA Pre-Out, 1 RCA Tape Out, 1 6.35 mm jack (headphones), 1 pair of speaker outputs