Meet Your Maker: Hi-Fi+ Visits Audio Research Corporation

Reviews of products from the US-based firm Audio Research Corporation have frequently graced the pages of Hi-Fi+, so that I was pleased to have the opportunity to visit the ARC factory in Plymouth, Minnesota (a suburb of the greater Minneapolis metropolitan area) to see how the firm’s components are made. What follows is a photo journal of my factory tour.

All ARC components are precision assembled by hand as you can see in this image of a technician installing individual electronic components on a circuit board. At each step along the way, technicians have at hand a “reference” assembly component that they can use as a means of double-checking their work (the “reference” circuit board is here shown to the technician’s left).

Leads from individual components (resistors, capacitors, inductors, semiconductors, etc.) are hand formed and trimmed.

Larger circuit boards, such as the one shown in the images, are fitted in tip-up frames for greater ease of assembly.

Here a set of partially completed circuit boards awaits the next step in assembly. In typical ARC fashion, each assembly step is followed by a careful inspection step, so that any assembly problems are caught and corrected as early as possible in the process.

Interestingly, this meticulous “build-inspect-build-inspect” procedure is followed for every single ARC product, regardless of price. While various ARC components –offer differing levels of performance in an absolute sense, the company takes great pride in the fact that all products bearing the Audio Research logo are manufactured to one uniformly high build quality standard.

All soldering on ARC component is done strictly by hand (no automated “wave soldering” is used at any time). Why? The answer: ARC claims that hand-soldered boards simply sound better. In fact, the “it sounds better” explanation lies behind virtually all of the manufacturing decisions implemented in the ARC factory.

Here a technician installs exotic and costly capacitors on a circuit board. On some models, ARC even goes to the extreme of positioning capacitors so that a precise gap is left open between the bottom of the capacitor and the top surface of the circuit board. Why? You guessed it: “It sounds better…”

As you might expect of a company famous for valve-based equipment, ARC uses a lot of vacuum tubes (or valves), each of which is thoroughly tested on tube testers like these and then hand-graded and matched.

This image shows a portion of ARC’s valve stock on hand. The hand-marked numbers on the sides of the cartons denote specific test values for the valves within. Should the valves in an ARC component ever fail, the firm can provide valves that are an exact match for the originals.

Here we see a close-up image of a TUNG-SOL KT120 valve, which is ARC’s power output valve of choice for use in many of its amplifiers.

This image shows an ARC VSi75 valve-type integrated amplifier that is well along in the assembly process. Pale blue protective tape is used on surface that might otherwise be prone to marring during assembly.

The rear panel of the VSi75 shows ARC’s typically clean layout. Every single ARC product undergoes thorough burn-in and then a full functional test, which leads up to the final hurdle each ARC component must pass prior to shipment; namely, an in-depth listening test. Absolutely nothing leaves the factory without first passing a listening test. Period. This particular VSi75 is nearing the stage in the process where it will be ready for burn-in.

ARC’s head of sales David Gordon proudly stands behind the mammoth chassis of a partially completed ARC Reference 750 monoblock amplifier. When finished, the giant amp will put out a staggering 750 watts with ultra-wide bandwidth and vanishingly low distortion. What is more, the amp will weigh a whopping 170 lbs. (77kg) once removed from its shipping crate, or about 270 lbs. (122kg) within its crate. (If you purchase a pair, be sure to invite several strong friends to help with the uncrating process).

The amp is so beefy that, during assembly, Reference 750 units are mounted on (no joke) modified engine stands originally designed to hold large-displacement V8 auto engines.

A side view of the Reference 750 monoblock amplifier under construction reveals its multi-story architecture. With 16 (!) output tubes, it is said the Reference 750 makes a fine audiophile-grade “space heater” for those living in colder climates.

The aforementioned engine, er, amplifier stands as used during construction of ARCs largest power amplifiers. According to ARC, the stands make it much easier to flip the behemoth amps upside down, as is occasionally necessary during assembly. Beefy casters also make it easier to roll the amps from one assembly station to the next.

This massive, ceiling-mounted engine hoist is used to lift and then lower ARC’s biggest power amplifiers into their shipping crates.

One of the joys of owning ARC equipment is that the products last a long time and can be repaired or rebuilt almost indefinitely. This image, for example, shows the interior of a special stockroom reserved specifically for parts used in ARC products that are no longer in production. Obviously, ARC takes its long-term commitment to its customers very seriously.

Treasures from the past: David Gordon holds an NOS (new old stock) faceplate for the firm’s classic D-79 power amplifier. ARC not only stocks functional parts for classic models, but cosmetic parts as well.

Here, a sample of the firm’s flagship, two-chassis Reference 10 preamplifier awaits final packing and shipment. I asked whether the ventilated Perspex (Plexiglas) top covers were standard or just for show and learned they are offered as standard on the Reference 10. Why Perspex covers? Once again, “They sound better…”

Audio Research is now part of the Fine Sounds S.p.A. group and accordingly ARC does some assembly and test work for select Wadia Digital components.

Teamwork: A portion of ARC’s assembly space is reserved specifically for construction and testing of select components from Fine Sounds S.p.A. sister brand Wadia Digital. Here, a nearly completed set of Wadia components awaits voltage assignments prior to burn-in and testing.

 A beautiful Wadia Digital disc player nears completion on the assembly line.

A bevy of Wadia Digital Model 121 Decoding Computers undergo burn-in in the ARC factory prior to final testing.