Reviewer: Jeff Day
Source: Garrard 301; Meridian 508.20 CD player as transport, Audio Logic 2400 vacuum tube DAC
Preamplifier: Tom Evans Audio Design Vibe
Integrated Amplifiers: Almarro A205A EL84 single-ended pentode; Sonic Impact Class T digital [in for review]; Shanling STP-80 Integrated Amplifier Underwood Hifi Level 2 [in for review]
Amplifiers: Fi 2A3 single-ended triode monoblocks; Yamamoto A-08 45 stereo [in for review]
Speakers: Avantgarde Duo 2.0; Omega Super 3 [in for review]
Cables: Nirvana S-X interconnects between DAC and preamplifier; Nirvana S-L interconnects between preamplifier and amplifiers; Nirvana S-L speaker cables between amplifiers and speakers; a custom Nirvana wiring harness to connect the Duos midrange and tweeter horns and woofer module; Cardas Neutral Reference digital cable; Nirvana digital cable [in for review]; Yamamoto Custom interconnect [in for review]
Stands: Atlantis Video Reference equipment rack, Billy Bags 2 shelf rack
Power line conditioning: none
Sundry accessories: none.
Room size: 15' x 25' x 8', short-wall setup
Review Component Retail: $2975/pr.

Single-ended triode (SET) amplifiers have taken the present-day American HiFi scene by storm. In case you're new to the audio hobby or the SET amplifier revolution which has gained immense popularity in recent years, a brief primer about SET history and their meteoric re-emergence on today's audio scene -- with an emphasis on Don Garber's contribution and the birth of Fi -- might be in order.

The invention of the vacuum tube is generally attributed to American inventor Thomas Edison in 1879 when he developed a vacuum-evacuated glass bulb containing a filament that emitted light when electricity was passed through it: The first light bulb. In 1883, Edison mounted a metal plate inside the glass bulb and observed that electrons flowed from the filament to the metal plate. This was later called the "Edison effect".

Edison did not continue to study the Edison effect. However, this phenomena caused the light bulb to go on for English scientist John Fleming who continued to study where Edison left off. Fleming placed a second electrode (the plate) beside the filament and in 1904, Fleming presented the result of his studies to the world: The diode. When electricity was applied to the filament, current flowed from the filament to the plate. The resulting diode is also known as a rectifier and still used in many vacuum tube amplifiers today to convert alternating current to direct current [see tube 3 and 4 below].

In 1906 another American, Lee de Forest, introduced a third electrode -- called a grid -- into the vacuum tube between the filament and the plate to create the triode. Lee de Forest found that when he applied current to the grid, he could amplify a signal passing through the tube and in so doing became the father of the single-ended triode or SET amplifier. In 1907, he patented the Audion triode tube, an event which brought vacuum tubes into mainstream American culture.

In this earliest period of amplifier design, tube circuits ran in class A. During that time, triodes were used for audio amplifiers in theaters, television sets and radios among other things. The power of those early amplifiers was low, the distortion and hum levels were high and the frequency response would be considered limited by today's standards.

A quick perusal through a 1941 Radio Engineering Handbook shows that early electronics designers responded to those limitations with new tube designs such as tetrodes (two grids between the filament and plate) and pentodes (three grids), the development of push-pull circuits and the application of negative feedback. In the late 1940s, Bell Labs developed the transistor and by the 1970s, the vacuum tube was largely replaced by these transistors in the US audio scene, with SET circuits mostly relegated to a dusty footnote in the history of electronics.

Evolution of an American Classic: Fi
Unlike in Japan and France, the glowing embers of the once strong SET fire appeared to have gone out permanently in America. Thankfully, this proved temporary as the fan of fate blew upon those darkened embers to bring a faint glow back to the ashes of the past when in the summer of 1957, a fateful meeting took place in Pennsylvania. A young college student named Don Garber had let his language requirement for graduation slip while going to school at Penn State. To make up for his oversight, Don put in four semesters of Spanish during the summer at Franklin & Marshall in Lancaster/ Pennsylvania while working a part-time job to pay the bills. Occasionally Don went to the Oregon Hotel bar to blow off a little steam and take a break from his Spanish studies. The Oregon was one of a number of backwoods Lancaster County bars known as 'hotels' because that's what most of them had been during their glory days. The Oregon was a great place for college students to hang out because it was close by, had a great bartender and the low light levels gave a cool blue tint to everything inside.

One night Don ran into John Grosh, a research engineer at the now long-defunct RCA research labs in Lancaster. John was at the bar conversing in Spanish with a couple of migrant workers that came in most evenings. Don took this as an opportunity to practice his Spanish -- ahem, among other things -- and joined in on the conversations. One night Don told John that he wanted to get into HiFi but didn't know how to go about it. John told him he should build his own and recommended that Don build a Heathkit W5-M, a 25-watt amp based on KT66 tubes. This was before stereo so the kit was a mono amplifier. When stereo became popular, Don put his new-found kit building skills to work and built another W5-M for a stereo pair. Over time, Don relegated the W5-Ms to the closet and replaced them with transistor gear "like everyone else had".

In the late 1980s or perhaps early 1990, Don realized that his solid-state gear didn't sound too good. Don got out his old W5-M amplifiers and found that they sounded better. While Don was thinking about how his transistor gear was bested by his old W5-M amplifiers, his friend John called up Don to tell him about his "new" Western Electric 91-A amps. John had just been given a pair of Western Electric 91-A 300B movie theater amplifiers by a friend who worked at Bell Labs. John said "You've got to hear this!" Don met with John to hear the Western Electric 91-As. They were "nice and scabby looking," recalls Don, "and looked like they'd been strapped onto projectors for 30 years and probably had been." When they fired up John's system with the Western Electrics, it sounded great and more importantly, played music with abandon.

Nobody was building SETs in America yet. Herb Reichert and JC Morrison -- who would later become famous for their work with SETs -- were devotees of the work of Arthur Loesch at the time. Then Noriyasu Komuru started building amps as did Gordon Rankin and Don was experimenting with 2A3 amplifiers. Once again the fires of SETs had been lit to burn in the consciousness of American audio.

News of SETs began to percolate into the American HiFi scene, nicely coinciding with the beginning of a trend of an increasingly disgruntled audio everyman who saw prices for good quality equipment spiral out of financial reach. In the 1970s, high quality audio was perceived to be generally

available to a wide economic cross section of the populace and many could share in the fun with some sense of equity. As the economic gap between consumer audio and high performance audio widened in the 1980s and 1990s, an audio high end evolved with an image of providing toys for the rich and excluding the audio everyman who wanted to join in the fun. Audio everymen wanted more access to good gear and less exclusionary pricing, more fun and camaraderie in the hobby and less snobbery and aloofness, more "sound of live music" reality and less emphasis on HiFi sound effects - and they considered cheapness an essential virtue.

In 1992, Don saw a little storefront for rent on 30 Watts Street while out for a walk through Soho in Manhattan - a little triangular space that was pretty nice [see above]. Don rented the store and fixed it up and called it Fi -- short for HiFi -- and began to resell vintage gear and the first single-ended amplifiers made in America. There was a placard in the window that read:

By that time Herb Reichert had built a 300B amp that he had in the store, and JC Morrison built a 6B4G (like a 2A3) that was in a big mahogany plinth with black powder-coated chassis that was really attractive. JC also made it available in an EL34 version. It was a beautiful amplifier but it never sold. About that time Gordon Rankin built an 845 amplifier and it sold, and if Don recollects correctly, it was Gordon's first SET sale. People drifted in and out of

Fi, with Noriyasu Komuru the only one who stayed around to actually work the store with Don for a while. The Fi store was making enough money to stay open but not really enough to make it worthwhile for all the work involved. About that time, the Sound Practices magazine was launched and Don advertised in it and sold two more amplifiers to enthusiasts on the West Coast. Don's first Sound Practices advertisement featured designs by Tim de Paravicini, Noriyasu Komuro, JC Morrison, Gordon Rankin and Herb Reichert. It proclaimed: "Triode amplifiers (45, 50, 211, 300B, 845), occasional pentodes, pipedreams, sirens, lollipops and Yoshinos" [see below].

The Birth of the Fi 2A3 Stereo Amplifier
At that time Don began to think that he might be able to do better just selling amplifiers. Don had been experimenting with 2A3 circuits and tried just about every circuit extant. He finally found one he really liked and began to make it simpler and simpler. Every time he made it simpler, it sounded better.

Once Don settled on the final circuit, he made his first product for sale in the store: The Fi 2A3 Stereo. That first amplifier sold for $1475 and was bought by a New Yorker who walked in off the street, listened to the amplifier, liked what he heard and bought it on the spot [see below]. A flyer for the original Fi 2A3 Stereo described Don's thoughts at the time:

"Fi began as a result of hearing a single-ended triode amp quite a few years ago. Much water over the dam and few regrets later, I've filtered out a few working hypotheses and a sort of direction."

"It seems to me that simplicity (often doubted and usually achieved by the most roundabout means) yields the most natural and truest results. This is what I hear and I can only guess why. This gives you a very low-power amplifier (in my case a direct-coupled 2A3). Maybe it's the fear of being taken for some kind of fool or the desire for a broader appeal, but it seems the designer's first reaction to the SE triode amp is to find some way to boost the power. I know. I've tried and I've listened to a lot of the paralleled amps, triode connected pentodes and so forth and the best I can say is 'not bad'. It seems to me that the power quest is a step backward."

"The real need is efficient speakers. I'm very pleased with my 95 dB/W/m system. What it does well it does to perfection but it won't do everything - not Mahler as if you were standing on the podium (if that's your taste). There are a

number of possibilities over 100dB available now and there will be more soon... Silver. The more the better. I've had MagneQuest's new all-silver outputs for three days as of this writing and they are opening up by the day. All descriptions come back to 'natural'. I try to build as simply, directly and as elegantly as possible and price accordingly. It seems putting the price in the stratosphere does appeal to some but I suspect it's eventually counterproductive."

As Don continued to build amplifiers, the Fi 2A3 Stereo continued to undergo refinements. The round-cornered black Fi Stereo [see below] was another step in the early evolution of the Fi 2A3. An early flyer describes this stage of the Fi 2A3 development:

"The Fi 2A3 is the result of a search for the purest, simplest and most elegant single-ended amplifier. It's direct-coupled, which is to say there are no coupling capacitors. The signal path consists of a 6SF5 single triode driver (nothing paralleled), a 2A3 directly heated triode, a MagneQuest DS025 output transformer and a few inches of silver wire. The only shared elements in the power supply are the power transformer (contract-built by Thordarson) and the 5Y3 rectifier.

Each side has its own filter network (SCR polypropylene capacitors and Dale wire-wound resistors) and each 2A3 has its own filament transformer. It's a very open, relaxed, dynamic and detailed amplifier. The price is $1475 with a two week money-back guarantee if returned in original condition. A 50% deposit is required to order, the balance payable upon delivery. Delivery in 30 days or less. 3 watts."

Don tests all the components used in his amplifiers by ear. In an amplifier, the coupling caps usually have the biggest influence on the sound. The Fi amps are direct- coupled so there are no coupling caps to affect the sound. With coupling caps not being a factor, the circuit is responsible for 95% of the sound you hear. Don continued to refine the amplifiers. The first resistors he used were Bradley film resistors. Don now uses Caddock resistors because they sound better but the basic circuit has remained unchanged. Grounding has evolved to make the amp quieter. It's a direct-heated, direct-coupled amplifier with AC on the filaments so it's a little bit noisy. Don tries to warn potential buyers ahead of time about the hum so they know what to expect. With my 103 dB/Watt/meter Avantgarde Duos, once the music is playing, you don't hear the hum but you will when the Fi is idling with music off. With the 93 dB/Watt/meter Omega Super 3s' single Fostex driver, you have to put your ear next to the driver to hear any hum at all so hum is a relative thing depending on how sensitive your loudspeakers are. Either way, it's not an issue when music is playing.