Analog Corner #311: Dynamic Sounds Associates Phono III phono preamplifier Page 2

The third and fourth toggle switches, located in a box labeled "Equalization," let you choose the desired EQ curve. The left-hand, three-position switch labeled "G2-RIAA-G1" selects RIAA in its center position and either G1 (pre-RIAA) or G2 (pre-RIAA 78) in the two other positions. Once in either G1 or G2 position, the rightmost toggle switch lets you choose between EQ1 (Columbia) and EQ2 (Decca/ffrr).

That's five equalization choices (RIAA and four additional ones). DSA should include a handy card describing all this that can be kept under the unit.

The instruction manual includes a 10-page appendix that discusses in great detail both the history and implementation of EQ curves in 78 and 33 1/3 rpm records and how the curves used in the Phono III were designed, implemented, and measured.

The blue "up/down" pushbuttons adjust either the resistive or the capacitive loading, depending on the setting of the first toggle. MC resistive loading can be set from 0 to 2550 ohms in 10 ohm steps. MM capacitive loading can be set from 120pF to 1400pF in 10pF steps. As already mentioned, MM resistive loading can also be set—to either 47k ohms or 100k ohms. The Phono III will remember the gain and loading settings for each input.

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Input A is special: Its first toggle switch has three positions, not two. The center one is for a custom resistive or capacitive load (resistive for MC, capacitive for MM). Under a small removable chassis top plate, you can access a set of sockets and insert your choice of resistors or capacitors. When the switch is in that center position, the large LED screen reads "- - -." This custom-loading option is laudable, but the available pushbutton settings will be sufficient for all but the most obsessed.

A nice feature: Normally, changes made to loading and gain using the remote control don't change the memorized settings. Thus, you can "play" with loading while listening in order to optimize a given recording (using loading as a "tone control") and then, if you hear a load setting you especially like, you change the memorized setting by getting up, walking over to the chassis, and pushing a blue button. You can also make gain changes permanent from the remote by making the adjustments when the Phono III is in Mute or Standby mode.

I ran the Lyra Atlas Lambda SL phono cartridge mounted on the SAT CF1-09 arm/XD-1 turntable into input A, the Miyajima Labs Infinity Mono mounted on the Kuzma 4 Point (on the XD-1's rear arm pod) into input B, and on the OMA K3 turntable, the Thales X-quisite ST cartridge mounted on its proprietary Schröder arm went to input C.

Ghost in the machine
I began listening through the SAT/Atlas combo with the loading set to 100 ohms via the blue buttons. About a minute in, the sound changed. What was happening? I looked at the Phono III's display and found that the loading had risen to 740 ohms. Regardless of where I set it (I tried 200 and 400 ohms), it would quickly rise by 640 ohms. I called Dr. Hurlburt, who was surprised and at first perplexed; this unit had undergone a great deal of break in before shipping and had performed perfectly. What changed?

Hurlburt sent a second Phono III, also tested and broken in, and guess what? Same thing!

Hurlburt did not put on his thinking cap, because he never takes it off. He suspected a static electricity buildup and suggested grounding the SAT turntable, which I did—it has a ground lug for that purpose—but that didn't solve the problem. He then suggested that I try a mono cartridge—finally the impedance did not change!

His diagnosis? A static electricity buildup was zapping the memory/logic board (or something), which caused the loading to change. With the mono cartridge, the dual differential circuit "nulled out" the static before it could reach the logic board.

I also tried the X-quisite stereo cartridge, and its impedance setting didn't change. Why? Its one-piece ceramic cantilever/coil former could not conduct a static charge into the Phono III.

Why didn't Hurlburt experience this problem in his own workshop? Because he lives in high-humidity Florida, where static electricity isn't an issue.

A short-term fix was to use the supplied RCA-to-XLR adapters on the SAT arm (thus running it "balanced/dual differential"). I then had three properly functioning inputs.

The long-term fix involved a circuit change to run the preamp balanced-only (originally, it ran single-ended into the single-ended inputs) and to make another small circuit change. Once this static electricity issue had been solved, the Phono III performed flawlessly.

621acorn.remThe sonic overview
If you are looking for a phono preamp with a timbral "personality," the Phono III might not be for you. It hasn't got one, not that I could identify. But if you want a phono preamp that gets out of the way and lets your cartridge or cartridges express their timbral personalities—all transducers have them to one degree or another—the Phono III could be for you.

Was it the sonic equal of the more-than-twice-the-cost CH Precision P1/X1? No. The sonic picture, though generously sized, was not as grand in scope nor as enveloping. The attack was a bit harder and less nuanced, the sustain not quite as generous. But because of the Phono III's jet-black background and quiet, its decay was the P1/X1's equal.

The just-released remix of John Lennon's first and most consequential solo album, John Lennon/Plastic Ono Band (0602507354541), is among the most accomplished and useful of classic rock remixes. (See My Back Pages in this issue.) Lennon didn't like his voice, and at his direction, the original mix puts it in the distance. The reissue's goal was to move it forward in the mix and add the vocal body that's on the multitrack but left behind in the mix.

The production is relatively simple, so there's not much room to mess things up. The remix packs vocal thrills, replacing Lennon's hollow, distant, tape-delayed-and-doubled original vocals with ones that duplicate the tape delay effect but put raw glottal textures almost in your lap as he screams his primal Janov pain. The remix also adds more bottom-end weight; in the wrong phono preamp's hands, that could produce dullness and unwanted lower- and midbass mud. Not here.

The Phono III's rendering of this exciting hi-rez digital remix seemed to me just what the producers and engineers wanted listeners to experience: more bottom-end weight and greater rhythmic insistence to Ringo's drums and Klaus Voormann's bass, and greater vocal expressiveness and (especially) natural texture from Lennon's vocals.

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For last fall's "Black Friday" Record Store Day, Zev Feldman's Resonance Records released a previously unreleased 1982 set by the underappreciated (although not in my home) Jamaican-born pianist Monty Alexander. Criteria Studio owner and Alexander fan Mack Emerman recorded Monty Alexander Love You Madly: Live at Bubba's (Resonance RLP 9047) to 24-track tape and then, after the concert, out of love and fan devotion, handed a surprised Alexander the 24-track tape.

It has now been mixed to analog two-track tape and mastered, both by Bernie Grundman. The release was limited to 2000 copies of the double LP. A few are still around, so grab it while you can.

The Phono III brought the stage forward and emphasized the attack, which with the Alexander is pleasingly aggressive. The CH provided a more nuanced attack and more sounding-board sustain on a set-back stage. Bassist Paul Berner and percussionist Robert Thomas Jr. appeared to sit well behind Alexander. But while the staging and attack differed, the two preamps' timbral presentations were quite similar. If you are a tube guy or gal, you probably wouldn't go for either presentation.

Playing with curves
As Hurlburt's excellent appendix points out, only older mono records require non-RIAA compensation, so I didn't try the Columbia curve on an original, mono Kind of Blue, but I did try it on a really old Columbia Masterworks LP of Tchaikovsky's Concerto in D Major with violinist Nathan Milstein and the CSO, conducted by Frederick Stock (ML 4053) and released on vinyl in 1948. Applying the Columbia post-78rpm curve made Milstein's violin spring to life, though I wouldn't call it "high fidelity."

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By 1954, RCA was issuing from tape "New Orthophonic" recordings like the famous, one-mike Also Sprach Zarathustra (LM-1806); the same recording was released six years later in stereo (LSC-1806). The curve was pretty much what a few years later became the RIAA curve, minus the 50Hz "turnover." Playback of that classic was best with the RIAA curve—no great surprise.

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Much "curve abuse" is still going on, with claims that these older curves were used by some labels into the '70s and beyond. It's bullshit. As one veteran Columbia Records mastering engineer asked me over the phone, "What are they smoking, crack?" Those extra curves are nice to have for people who own and play really old mono records, but for most of us, it's unnecessary.

Conclusion
Just as I was about to hand in this column, a new Electric Recording Company release arrived: A Debussy Recital (ERC069/[UK] Columbia SAX 2469), performed by Samson François. Limited to 300 copies, it was already sold out when it arrived. (Why doesn't someone relicense these great titles and reissue them at lower cost?) On Discogs, five people were listed as owning the original, and 181 wanted a copy. No copies were for sale (footnote 2). I can't imagine what an original might cost.

This solo, stereo piano recording from 1962 is a sonic spectacular, timbrally, texturally, dynamically, and however else you wish to gauge a great recording. The sensation of a live piano recital delivered through the DSA Phono III stared me in the ear. The sonic picture was absolutely spectacular. It left me aquiver. So, earlier in the month, did recordings by The Clash; Peter, Paul and Mary; Floating Points with Pharoah Sanders, and many others. So, forget about comparisons. There's much to like about DSA's Phono III. I can't guarantee you'll love it, but they guarantee that if you don't, you can return it.


Footnote 2: Already though—I'm writing this a day after promos were received—seven "mint" copies of the ERC issue are on Discogs, priced at $579 and up.

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COMMENTS
T-NYC's picture

.. however, he shared it with you. Fabulous! Despite that and the lack of a lab report, I suspect this is a fine product.

Jack L's picture

Hi

Surely constant-current source topology is unique to ensure constant current feeding the active solid state devices irrespective of the loading resistance change due to overheating etc. This is crucial for power amp devices to prevent 'thermal run-away".

It has been a pretty popular circuit design for seasoned DIYers way over a decade or more now. No rocket science.

Yet it is rarely used in commercial amp design/builds!! Too complicated ??? IMO, Nelson Pass is the first guy employed in his amps, e.g. First Watt, used EVEN in his Class A output power stage designs many years back.

Now it is also employed in this phono-preamp. Surely such simple topology does not need a PH.D. electric engineering design at all.

Jack L

Arvo Palm-Leis's picture

Thanks again, Michael, for the heads up about a cool record. The story behind Monty Alexander's Live at Bubba's is fascinating, and the outstanding and accomplished people involved in getting the music to tape and then to LP were doing it for love more than anything. I was very pleased to find it for $46 at Amazon; alas, there are no local record stores around these parts. The music and sound are very good.

https://www.amazon.com/gp/product/B08L3Q6GJH

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