Sentec EQ11 phono preamplifier

With quiet elegance, the Sentec EQ11 phono stage and equalizer entered my expanding world of gramophone dreams. The EQ11 ($2500) is a modestly sized, tubed phono stage with the industry-standard RIAA phono equalization and five other EQ curves. These additional curves are for records pressed by companies that did not fully or promptly comply with the new, supposedly global industry standard introduced by the Recording Industry Association of America (RIAA) in 1954.

Before 1955, every record company chose and applied its own version of recording equalization; there were over 100 combinations of turnover and rolloff frequencies in use, the main ones being Columbia-78, Decca-U.S., European (various), Victor-78 (various), Associated, BBC, NAB, Orthacoustic, World, Columbia LP, Decca ffrr 78 and microgroove, and AES.

The Sentec EQ11 comes in an attractive steel chassis of hammertone gray with a gold-anodized faceplate and, sticking up through the top plate, pairs of JAN G.E. 5751 (special 12AX7) and JAN Philips 6189W tubes. A single, vintage-style black knob selects among six settings, labeled thusly:

1) NARTB, NAB old
2) 78, Decca ffrr 78
3) CCIR, Decca LP ffrr
4) RIAA, New Ortho
5) Columbia LP
6) AES, Philips, Capitol

These six equalizations reflect most of the major variations found in 78, 45, and 33 1/3rpm gramophone recordings made between 1920 and 1965. In 1948, in response to the noise and short playing times of shellac 78s, Columbia Records introduced the microgrooved long-playing vinyl 331/3rpm record, in diameters of 10" and 12". Not to be outgunned or outsold, RCA Victor, in 1949, introduced the 7", 45rpm vinyl record. The 7" 45 was not long-playing, but it was small and cheap, and most pop, "hillbilly," "race," and children's records would hereafter be issued in that format, replacing the 10" 78 as the reigning single format. The first stereo vinyl LP appeared around 1958, but stereo records did not become popular or even common until about 1965. Most 45s were pressed in mono until about 1970. At first, stereo recordings appealed mostly to adult listeners, who favored 12" LPs featuring classical, cabaret, and jazz artists.

The 15 years from 1955 to 1970 were a period of intense competition for all European and US record companies. Record stores and radio stations flourished, even in small farm towns. Finding artists, recording hit songs, and grabbing as much of the rapidly evolving market as possible were not easy tasks. Postwar artists such as Charlie Parker and Elvis Presley needed to punch their way into the public consciousness. Each record label began selling its own version of good sound as well as of good music. Good-sounding records got more play on the radio, and thus more attention from listeners. Every record producer and engineer strived to develop his own special technology—a signature sound.

During this period, the RIAA worked hard to enforce its new "universal" standards of equalization for recording and playback, as part of a larger program that included standardizing record size, groove width, and playing times per side. More often than not, the RIAA's newfangled EQ was at odds with the established agendas and sonic identities of record labels and producers. Consequently, almost a decade elapsed before all labels had gotten in line with the new strategy of RIAA pre-emphasis (footnote 1). This period was also a time of great achievement in music. Parker, Presley, James Brown, Artie Shaw, the Carter Family, Duke Ellington, Hank Williams, Johnny Cash, Ella Fitzgerald, Skip James, Edith Piaf, Bill Monroe, John Coltrane, Frank Sinatra, Bob Dylan, Little Richard, the Beatles, and a billion other musical geniuses all recorded between 1945 and 1965. The majority of these artists' original recordings were made in mono to recording specifications that did not conform to RIAA standards.

Audiophiles, home-audio DIYers, and record collectors were the first to notice the lack of compatibility of discs and playback gear, and the first to grumble and seek help. Manufacturers of popular ceramic and crystal cartridges were put on notice to tame their rising response curves, while makers of specialty preamps responded with enhanced tone controls and selectable EQ curves corresponding to the various record labels' deviations from the RIAA curve. RCA was the first to actively lobby for the RIAA standard, and the first to comply with them, in 1955.

By 1975, most audiophile amplifiers had banished tone controls, mono switches, and variable EQ selectors, considering them old-fashioned, no-longer-needed "corruptions" of the signal path's "purity." Forty years later, we have an outbreak of high-end manufacturers introducing new mono and 78rpm cartridges, and variable-EQ preamps designed to make the life of the vintage record collector more pleasurable.

I tell you all this because it's important to understand that if you start buying a lot of collectible old records pressed before 1965, you'll certainly notice that the music on some labels sounds a lot better than the music on others. The purpose of the Sentec EQ11 is to make many of those differences go away. The EQ11's selection of EQ curves is similar to those that came standard on many "audiophile" preamps made between 1955 and 1965.

Like the Miyajima Spirit Mono cartridge The Sentec EQ11 preamp-equalizer are luxury products designed for the collector of vintage vinyl who wants to hear his or her valued records sound as close to, and maybe even substantially better than, what he or she remembers from the old days. This combination of pure mono cartridge and selectable-EQ preamp can show you a lot of what you still haven't heard from your old records. This combo, and perhaps others like it, not only makes the records of the past sound good, it makes them sound the way your brain knows they're supposed to sound—the way your heart remembers them sounding.

Any time you play a record and your brain jumps up to announce, That's it, buddy! That's the way this record is supposed to sound!, that's the surest sign that you're cooking on good audio gas. This feeling is also exactly what is missing from the experience of most recordings remastered, re-equalized, and reissued on 180gm vinyl pressings.

I have this totally magic album, Dinu Lipatti Plays Bach and Mozart (Columbia Masterworks ML 4633). I often play the Bach side for my guests, just to show them what quiet authority and expressive understatement sound like. But it always sounds kind of hard and bright, a little cool and thin. Some guests blame it on my amp or speakers. When I first installed the Sentec EQ11, I thought, Okay, let me try that Dinu! When I switched from the Sentec's RIAA curve to its Columbia LP curve, I smiled and nodded my thanks. The sound wasn't radically different—just enough to make every note more relaxed, open, and distinctly colorful. Weight and body appeared as if from nowhere. The piano became a tangible, vibrating object. The effect was like the complete and sudden vanishing of a nagging low-grade headache. With each old record I tried, the result of switching EQs ranged from unnoticeable to Oh my god, I am so happy to have this thing!

Footnote 1: See Keith Howard's comprehensive discussion of the RIAA curve here.—Ed.
US distributor: Tone Imports

doak's picture

Or is he FOS?

If not someone is.

toon's picture

The article states that there were over 100 variations. What is to say that those chosen by Sentec are the correct ones? What happens if I change tubes? To further extend the comment by doak I think more than one person is FOS. Another very small niche product for the gullible.Modest appearance and wall-wart power supply for $2500? What a total POS.

jokeka's picture

So, you've listened to it? Or does its "modest appearance" preclude that and reveal what you actually care about?

Osgood Crinkly III's picture

Looks like a Heathkit.

Rick Tomaszewicz's picture

would it be a conflict of interest for you to enter a comment on this article?

toon's picture

I care about music. But I also believe we should receive good design for a very niche component that costs 2500 with a wallwart( I've built better regulated power supplies for only $60 -and that's in Canadian currency!). Would you consider a BMW M5 worth the money if it still performed as well but had an exterior that was designed by a poor designer with little imagination and was built like a box? Really, there are many priorities for the audiophile, and music lover. Is it a sin to ask for quality in the packaging as well as what's inside.Especially at the price point of the Entec?

xyzip's picture

Funny thing about the appearance/ styling of this product (since that seems to be the drift of the comments)-- when I saw the photo here I thought, immediately, wow, what a brilliant match for the gray Garrard 301 schedule one that I use!

Silvery hammerite enamel, tubes & bakelite knobs, even the plain-font lab-style black enamel faceplate badges are an exacting equivalent for the styling-- call it Coldwar Chic-- of the the Garrard 301.

{It may be surprising to think this, but penetrating blue leds + Cnc lasercut anodized AL slabs--- don't look too simpatico, next to a Garrard, an EMT, a Neumann deck.}

As to the power supply, generally the wallwart thing at this price level is a placeholder sort of thing, and the manufacturer offers another, more substantial & higher capacity outboard SE external supply as an option. In an enclosure matching the signalpath unit. So that may happen. Or not, who knows. All in all, I'd rather have a fat *external* wallwart, than a troublesome *internal* psu that is wedged-in to keep the product small.

I have nothing to do with this product, but it's worth stating some alternative viewpoints. And I would like to see a more elaborate followup to this.