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 blog 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 access.
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 potential assembly problems, if any, 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 simple answer: ARC claims hand-soldered circuit 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 space is left open between the bottom of the capacitor and the surface of the circuit board. Why? You guessed it: “It sounds better…”
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, bring along lots of strong friends to help with the uncrating process).
The amp is so beefy that, during assembly, Reference 750 units are frequently mounted on (no joke) modified engine stands originally designed to hold large-displacement V8 auto engines.
A side view of the Reference 750 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.
As you might expect of a company famous for valve-based equipment, ARC uses a lot of vacuum tubes (or valves), each of which are 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 valves in an ARC component ever fail, the firm can provide replacement valves that are exact matches for the original units.