Air Tight ATC-1 Preamplifier and ATM-4 Amplifier
by Michel Bérard
Le Magazine Son et Image, Volume 12 Number 2, January 2011
The reputation of Air Tight equipment could hardly get any better. These are products with a heritage whose roots extend as far back as 1925. Some people remember the Luxman-branded products made by the Lux Corporation, founded by M.T. Hayakawa and his brother K. Yoshikawa. Luxman's reputation was to be built mainly on the quality of its transformers. It was especially in the 70s and 80s that Luxman came into the high fidelity fold, thanks this time to the quality of its amplifier tubes. Luxman gear in this era became the dream of an international community of audiophiles.
In the mid-eighties, a serious marketing error forced the creation of Air Tight. Luxman had joined the Alpine Electronics group. To compete with Yamaha, the company was henceforth to make less expensive products and distribute them through chains like Costco. This move created confusion in the specialized market. Fortunately, at this time, in 1984 to be precise, M. Astushi Miura left Alpine Electronics to create Air Tight, save the existing high end equity and pursue the original mission. Design of the first Air Tight amplifier, the ATM-1, was begun in 1985.
Now it's twenty-five years later and I'm happy to comment on two products born of Mr. Miura's determination to produce equipment of exceptional quality.
The ATC-1 Preamplifier
This is the most affordable preamplifier in the Air Tight line (the next models up being the ATC-2, the ATC-3 and the ATE-2001 Reference). It uses five 12AX7 tubes. It has three stereo RCA inputs plus a "monitor/record" input/output pair and a phono input rated for 1.8mV, suitable for a moving magnet or a high output moving coil cartridge. There is no low-level MC input. The unit's classic design is not ostentatious. There are two sets of output terminals.
The ATM-4 Amplifier
The amplifier uses four 6L6GC (5881) output tubes. The small-signal tubes are two 6FQ7 and one 12AT7. Speakers can be connected to either the 4-ohm or the 8-ohm terminals. Rated power is 24 watts per channel at 8 ohms. The ATM-4 is equipped with two inputs which can be selected at the touch of a button on the front panel. The level of input attenuation can be selected, so as to suit a preamplifier or a directly connected source like a CD player. All connections are easy to make. The only point to keep in mind is that the input terminal pairs are aligned horizontally, not vertically.
I was lent a pair of Air Tight Bonsai mini-speakers and a REL T5 subwoofer for these sessions. However I did all the tests with my Verity Audio Parsifals. The Bonsai minis with the REL sub would not have done justice to the electronics in the test, even though you might suppose that 24 watts of output would not be enough to drive the power-hungry Parsifals without straining. The Bonsais at $1,300 and the REL T5 at $535 could still be a good choice for a small listening space. The Air Tight Bonsai minispeakers are known for their sound quality in the mid and high frequencies, and when accompanied by a sub like the REL T5 with an 8-inch woofer, well, there's a compact team with a lot to offer.
While trying out my setup with the test gear, I noticed that the system was especially sensitive and that best results were obtained when the equipment was isolated with antivibration feet. Recall too that tubes are sensitive to mechanical vibration and that isolating them from the support reduces the microphonic effect. Power cables also make a difference. Properly chosen, they make a noticeable improvement in the performance of the two units.
I began with my familiar references. As a first general impression, what comes from the ATC-1 and ATM-4 pair is marked by resolution and finesse. There is an intelligent blend of the qualities of tubes and of transistors and none of the extra warmth that sometimes accompanies tube amplifiers. And as I expected, there was power to spare in spite of the 24 watt per channel limit. The music is articulate, the soundstage airy and open.
I listened in detail to Shirley Horn's "If You Go" from the album You Won't Forget Me. Shirley's voice was properly placed in space, right in front of the listener, subtle and warm. Then the piano came in with finely reproduced harmonics. Cymbals followed without fuss and everything came together. You don't get the authority and deep bass of a high-powered amp but the whole is coherent.
Now it was the turn of the score from the film Les Choristes. It was interesting to hear the children's choir so well articulated and the soloists' voices emanating from space. Liveliness, articulation. It was easy to perceive the singers in rows and all the surrounding space. Rich and vast.
A change of style now, "Night Sweats" from Larry Carlton's Sapphire Blue album. Air Tight makes you tap your feet. You give yourself up to the rhythm. I had absolutely no desire to zap to the next track.
For a study in subtlety, next came "Night on the Champs Élysées" (Take 1) by Miles Davis, from the film Ascenseur pour l'Échafaud. Bewitching. Miles' suave trumpet, the double bass keeping time and the brushes clearly defined on the snare. The whole piece full of finesse, you could practically feel the atmosphere of a smoky bar of the time.
My new reference for medieval music is Convivencia by La Mandragore. Cooked up by the Air Tights, you'd take a second helping. An exotic dish in which the voice blends with recorder, oud and percussion on darbuka, cajon, bendir and bells. An audiophile delight.
Now to listen to something new. Recently I've added a music server to my arsenal: a laptop computer which is connected to my converter and can play high-resolution digital files. This is useful in evaluating high-resolution gear and that's how it turned out with the Air Tights. I had on hand a 24-bit/96 kHz file of Holst's The Planets played by the Buzz Brass. I had a good memory of the sound of my reference system. The Air Tight pair succeeded wonderfully in restituting the information down to the slightest details. That confirmed again my decision to test them with speakers at the same level. With a quarter of the power of my reference amp, there was a difference detectable in the low bass, but the results were still impressive.
Next came Deserts by La Nef. As with the track by La Mandragore, I was well served by the mix of flutes, oriental percussion, tambourine and mouth harp. The Air Tights rendered the piece with brio, my ear was alert for the tiniest shadings of the music.
All in all, the Air Tight ATC-1 and ATM-4 make an impressive pair, and I know I didn't explore all they had to offer. There would have been even more had they been matched with a slightly more efficient pair of speakers. This is a seriously good pairing which can go to the top of the list in its price range.
Magazine Son & Image January 2011