An A-Shopper Review


Audio Research SP-3 Tube Preamp:
Still musical after all these years


      If I may state an obvious to those who have been in audio for many years, Audio Research Corporation (ARC) started out as a tube audio equipment specialist at the inauspicious time when the transistor was beginning its reign as the dominant output device of the electronic industry. Taking a contrarian approach, ARC set the stage toward establishing an immutable truth--that there is no single path to musical enjoyment. For its success, ARC established itself as a marque of superlative excellence, much like Mercedes. For a company to have consistently produced a line of musically compelling products, one must be guided not only by a strong leadership but a visionary one at that. I have never met William Z. Johnson, but from afar I admire him for his ability to steer his company to transcend its past achievements. By the way and for the record, ARC did had one major setback. Its first venture into transistorized components right after the established SP-3 series was a phenomenal flop.

The Model SP-3 Package

      One of the first products of ARC was the model SP-3. It is of all-aluminum construction with a two color anodized front panel. The equipment under review has a gold and black face, an elegant retro look that is as fashionable today as it was then.

      The SP-3 employs eight ECC83/12AX7A tubes: three for the phono section and five for the line and tone control circuits. Unlike the preamps presently produced by ARC, the SP-3 sports more options--2 magnetic phono inputs, 2 tape inputs, tuner, 1 spare input, and 2 main outputs--and push button switches: main power, preamp outlets, tone, the tape monitors, and magnetic phono 2. There are also knobs for volume level, source, mode (mono, stereo, reverse, left, right), contour, base, treble, and balance.

      The equipment at hand has just been serviced by ARC. Because the SP-3 is about 25 years old, ARC has found that the power supply capacitors of these units are becoming weak and dried up. A unit with this malady sounds bland and lifeless. In some instances, the volume pots also need to be replaced. Anyhow, ARC does a superb job of rejuvenating the SP-3 with its inventory of replacement parts for these units. The SP-3 came back from the factory spankingly clean inside and out. I also noticed that two capacitors in the phono section have been updated to polypropylene types. The good part about having ARC service your unit is the assurance of factory quality parts and worksmanship.There was a review of the SP-3 in one of the major zines a few years back. The author found the review unit diffused and lacking in dynamics, etc. Could it simply be that the equipment needed to be serviced?

Listening Method

      The following equipment were used to evaluate the SP-3: Audible Illusions Modulus 3 preamplifier, Pink Triangle turntable with Premier MMT and Promethean Green cartridge, JVC XL-Z1050 compact disk player all connected through an Inouye power conditioner, Sound Dynamics 300Ti, Spendor SP-1, and Linn Index speakers, XLO Type 5 speaker cables and Promethean Bandpass and MIT interconnects. For amplification, I used the Classe' DR-9 and the VTL 120/50.

      With my recent purchase of an equipment rack, I have finally been able to set up the Pink Triangle Turntable. I first listened to my reference system using the Audible Illusions Modulus 3. The Modulus 3 displayed its typical strengths in soundstaging, dynamics, clarity, and tight bass lines. I needed to get accustomed to its line and phono sections. Next, I switched to the SP-3. Kindly note that this was after breaking in the SP-3 for around 50 hours of listening. (Out of the box from the factory, the SP-3 sounded bright in the highs and wobbly at the bottom. Don't worry. It will blossom.)

Phono excellence

      The SP-3 is a knockout performer for those who prefer to listen to records . It competently followed in the footsteps of the Modulus 3 in almost all aspects. It was dynamic, articulate, and alluring with its sweet portrayal of the highs. In fact, it bettered the Modulus in one critical area---soundstaging. This was a surprise since the Modulus 3 is no pushover in this regard. The SP-3 presented more depth and air. I could peer through more layers. There was a deeper illusion of the music's source. I noticed this immediately after switching the preamps and verified it by playing several records that I am very familiar with.

      Neverthess, the Modulus 3 kept a tighter reign on the bass notes. It conveyed these with solidity and authority. In comparison, the SP-3's bass was a bit bashful and softer. It's like it did not have the fervor and confidence. Moreover, the Modulus 3 presented a more accurate balance. The SP-3 has a slight midband prominence, giving it an feeling of immediacy. The SP-3 as mentioned earlier also has a slight tendency toward giving highs a slightly sweeter interpretation. Some reviewers had previously found the SP-3 both alluring and romantic. I agree and believe this to be one of its endearing qualities. I was so enthralled by its performance that for several days I did not bother to listen to compact discs.

So how's the line?

      It's a different story. I have no explanation except the deduction that the SP-3 was optimized for phono/record retrieval. With compact discs, the Modulus 3 showed its superior qualities. In contrast, this is where the SP-3 shows its age. While the SP-3 came indeed very close to the Modulus 3, this time around, it was clearly the subordinate. It lacked the clarity and articulation that it had portrayed with records. It was like there was a thin veil over the music. It was harder to peer through the soundstage and to mentally visualize the spatial imagery. The canvas upon which the music is portrayed became narrower and murky. It is not that the SP-3 is a walkover or unsatisfactory. Frankly, I enjoyed listening to compact discs via the SP-3. It's just that it's performance is not at par with its exemplary record retrieval abilities, hence my mild disappointment.

      A caveat about using the line section is its high output voltage. You only have to turn the level knob three notches and you're already at an ear-splitting level. It's like you are constrained to two listening levels--loud or soft.

Does it serve the music?

      Yes, very definitely. The SP-3 is one of a few preamps that I have come across that I believe you would want not just to own and keep but also to listen to. It is captivating, especially when playing records. You want to keep listening to music because it is such a wonderful experience.

      I have seen SP-3's in very good to excellent condition for around $500. ARC service will probably cost another $300. For a total outlay of $800, inexpensive considering the current prices of high end equipment, you can have a soon to be classic tube preamp that is a joy to own. The SP-3 deserves four clefs as a phono preamp and three as a line preamp. This is a classic buy.

by Rome Castellanes

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