POSITIVE FEEDBACK ONLINE - ISSUE 27
3i EL-34 integrated
as reviewed by Francisco Duran
There is a lot to be said about an integrated amplifier—plug and play is an apt description. This was the case at my house last summer, when the complications of running a passive line stage into a pair of monoblocks gave way to the Audio Space AS-3i integrated tube amp, a compact, 30-pound chunk of high grade steel with a gleaming mirror polished finish and glowing glass. The AS-3i is equipped to handle three sources and a pair of headphones. The headphone jack is mounted on the front panel, not on the back, which is good if you are one of those extremely clumsy audio folks. I am not a "phones" kind of guy, so did not use the headphone amp very much, but when I did, I heard a clean and open signal.
The front panel of the AS-3i sports a toggle switch labeled NF MODE, which switches the feedback in and out, and another toggle labeled MODE to switch between ultralinear and triode operation. There are no "correct" settings for these switches, so I changed the settings to suit my mood or the sonics of the disc I was playing. Experiment for maximum pleasure. The AS-3i's volume and input selector knobs have a solid feel. Biasing the output tubes is easy, as there are bias pots on the top of the chassis. The job will be painless unless you are a total klutz. The only thing missing from the AS-3i is a remote volume control. It would have been handy to change volume from the comfort of my well-worn leather couch.
Another nice feature of the AS-3i is that it can be run as a power amp only, bypassing the internal preamplifier. I did run it that way (with my Reference Line Passive line stage) from time to time, but kept coming back to the integrated version for its simplicity and ease of use. The question of whether simpler is better is as old as the debate about tubes versus solid state or digital versus analog. Because a single chassis containing an amp and a preamp has a shorter signal path and eliminates one set of interconnects, it should in theory sound better than a multitude of boxes, wires, and internal components, but this is not always the case. I love to switch boxes (especially amps) in and out of my system. If I went the integrated amp route, I would probably not be satisfied with one, and would be switching at least two or three in and out at regular intervals. A tube integrated, a solid-state design, and a hybrid would be good for starters, but one of those amps would have to be as flexible as the Audio Space, so that I could use a preamp if I felt the need. So much for simplicity.
I rounded up the usual subjects for this review, meaning that the Audio Space amp was used to run everything sitting on my rack, from the TV cable box to the FM tuner to the CD player to my lovely Kuzma turntable. I did experiment with tube rolling. I left the stock EL34 output tubes alone, but changed the two 12AU7s and single 12AX7 labeled "Audio Space" for two NOS RCAs and one NOS Sylvania. The stock tubes were much noisier than the NOS versions. The NOS tubes also sounded cleaner, more holographic, and more dimensional. I also tried substitutes from J&J Electronic with great success, and these may appeal to owners who are less adventurous, or less willing to spend money on NOS tubes.
The real fun with the AS-3i was the way it handled musical pace and timing. In other words, this amp boogies! I put on Joe Satriani's Surfing With the Alien CD, and this great recording had my head bopping and feet tapping. Satriani's fingers on the title track and "Crushing Day" were lightning fast. I must emphasize that pace or rhythm never sounded exaggerated, but provided a level of involvement that was very inviting. This, plus its slight warm character, made the AS-3i a vehicle for sweeping me into the music.
The AS-3i did pretty well in terms of its tonal accuracy. The vocals of Paul Cotton and Rusty Young on Poco's Legend album were a case in point. I have a Mobile Fidelity pressing, and while Mo Fi did their best, this album is not at the pinnacle of the recording arts. Still, vocals had a tonal accuracy that transcended the limitations of the recording. The same thing happened with Box of Frogs' self-titled album. John Fiddler's rough, bluesy, tenor voice was appropriately textured and lifelike, and the tonality was as good as the recording could make it sound. Continuing to search for an audiophile-grade recording in my collection proved fruitless. Avoiding Steely Dan's Greatest Hits, I put on Ian Dury, Neil Young and the Shocking Pinks, and a Mike Pinder solo album. These albums proved that the AS-3i possessed harmonic correctness in the midrange. The sound was clean, detailed, and holographic, with good tonality. It was only when I compared the Audio Space amp to my more expensive Margules Audio U280SC that the AS-3i's weaknesses in the midrange were exposed. At that point, I could hear a slight amount of grain in the mids. On the "Baby Let me In" track of Still Feels Good, Tom Johnson's solo effort away from the Doobie Brothers, his voice was slightly congealed and not as clean as it should have been, and this made it a little more difficult to hear into the recording. The Margules had a more effortless and slightly cooler presentation.
The AS-3i also did well in the top range. On Surfing With the Alien, the tracks "Ice 9" and "Crushing Day" sailed through this amp like greased lighting. The treble performance was nicely controlled and extended. There was no splashiness or brightness. Neither was there a lack of air. There was a slight rounding and warmth, but only enough to pull me into the music. Boogie factor was evident in the way Satriani's fingers effortlessly picked through the above-mentioned songs. While not as open-sounding as my reference amp, the soundstage on most recordings extended slightly past the outside edges of my speakers, and slightly above. The AS-3i is not the last word in detail retrieval, but it is good enough. It does not obscure the musical performance or mask too much detail.
As usual. I played quite a few movies through the AS-3i. Watching action movies like Congo, No Escape, and Soldier proved helpful in showcasing the amplifier's dynamic capabilities. The explosions and gunshots sounded rock solid and powerfully deep. I was slack jawed! Hearing movies through this amp was a lot of fun. Of course, I didn't have surround sound with this two-channel amp, but the tube circuitry provided a holographic experience.
Playing some of my favorite orchestral passages from guys like Stravinsky, Respighi, and Copland proved equally rewarding. When an orchestra hits bottom, you know it with this amp. The bass lines on the song "Little Darling" (again from Poco's Legend) sounded powerful, full, and fast. Boom and bloom were kept to a minimum. Of course, this was with my Dali Euphonia MS-4 loudspeakers, which are an easy load. You could easily overdo it with less amplifier-friendly speakers, but why would you partner this cute little amp with less-than-friendly speakers in the first place? The AS-3i drove my Dalis with ease, in either triode or ultralinear mode.
The last comparison I made with the Audio Space AS-3i was with the Jasmine Audio Piano integrated amp. The Piano's price is comparable, as is its power rating (43 push/pull watts), and its use of four EL34 output tubes. There were no Marquis of Queensbury rules of engagement for these two amps. They took the gloves off, spit out their mouthpieces, and came out scrapping! At the end of the bout, it wasn't as good a day for the Jasmine amp as it was for the AS-3i. The Jasmine did not sound bad, but when the nits began to get picked, its treble had a slight chalkiness. Its bass was nice, but not as dramatic, powerful, or deep as the AS3i's. Its pace was only fair, and it was not as rhythmically inviting as the Audio Space. The Piano amp sounded more matter-of-fact, which made it harder to get involved with the music. Inner detail was good, and micro details were noticeably smooth. The Piano is more of a minimalist design, and it has far less flexibility than the AS3i. Both amps were quiet in operation, but the volume control on the Piano was very noisy, while the controls on the Audio Space were quiet. To be fair, the Piano amp is nicely built, and looks beautiful, and I much preferred its speaker binding posts to the ones on the Audio Space.
The Dali Euphonia MS4s are very musical, yet at the same time very revealing. They will show you what is up with whatever components you hook up to them. Aside from some minor shortcomings, the Audio Space AS-3i delivered the musical goods every time. In fact, I didn't realize it until later, but night after night I looked forward to coming home, turning on the AS-3i, and listening to music. With its musical, inviting character and its compact functionality, the Audio Space AS-3i makes a strong argument in favor of the simpler-is-better approach to high-end audio. Highly recommended! Francisco Duran