Analog Corner

The Orb flattener is easy to use. Just open, place the record over the glass plate's spindle, lower and secure the cover, and press a button. The number of times you press controls the final setting. The normal cycle takes two hours of heating and an additional two hours of cooling—all controlled and monitored via a single, square, black push button and seven blue LEDs.

Two semiconductor heater films, one on the top plate and one on the bottom plate, heat only the record's outer edge and center, thus avoiding groove damage. The system carefully controls heat-up and cool-down temperatures.

There are three heat and record size setting options (low, medium, and high heat; 7", 10", and 12" records). Medium heat is the standard setting, with Low suggested for the first try on "rare or precious" discs. High is recommended when medium doesn't work and you're willing to chance it. LEDs keep you informed about time as the heating and cooling proceeds, and an end-of-cycle alarm and flashing lights let you know it's safe to remove the record.

Some records can't be safely flattened with the Orb, either due to the shape, the vinyl formulation, or something else: Orb recommends not trying to flatten very thin records, records from Sheffield Labs, "Super Analogue" discs, and a few others. But most of your warped records will be flattened without damage by this essential accessory. It's much cheaper than some of the alternatives. Every audio club ought to have one to pass around. Every vinyl fan who can afford it should get their own.

Speed Kills
Get ready for some mind-numbing numbers.

After my OMA K3 turntable review was published, I received a text message from SAT's Marc Gomez, who objected (in a nice way) to my statement that the "K3 produced the best overall measurements." He was right to object. The OMA's mean frequency (for the 3150Hz test tone) was 3150.2Hz. The SAT's was 3149.9Hz. The low-pass measurements show the OMA's maximum relative deviation as –0.01%/+0.03% while the SAT XD-1's was –0.01%/+0.02%. The XD-1 was better by 0.01%. In absolute terms, the OMA's filtered measurement was –0.6Hz/+1.0Hz while the SAT's was –0.5Hz/+0.7Hz.

In other words, while the differences were minuscule, I erred when I wrote that the K3's measurements were better. My mathlexia is no excuse.

Shaknspin contains a 9-degrees-of-freedom sensor that measures rotational platter speed 500 times per second. The 100gm device is best placed directly adjacent to the spindle to keep the mass as close as possible to the platter center. There's now an iPhone app that (for me) makes it easy to download the collected data and present it neatly. Here are the shaknspin results for the SAT (fig.1) and OMA (fig.2) turntables. It's a near dead-heat, but the SAT's results are slightly better. Note how close the wow and flutter (W/F) measurements are: The OMA's W/F is 0.12/0.03. The SATs is 0.10/0.03. So the SAT's are slightly better. Not that you'd notice.

Now look at the jitter percentage, which is the average of the speed variations per second presented as a percentage of the average speed. It's how much correcting and adjusting the electronics have to do to maintain the correct speed. Here, the OMA's measurement—0.152—is slightly better than the SAT's measurement: 0.159. Otherwise, the SAT's measurements are slightly better overall, but I'd bet both are within the margin of measurement error (whatever that might be here). Anyway, these measurements are not likely to be sonic predictors, as the differences, even if they're real, are almost certainly too small to detect.

The shaknspin app also provides, in an Excel spreadsheet, a "speed run" that gives about 4000 individual speed measurements in an 8-second run. It'll dizzy your head!

I decided to take a fresh set of Platterspeed measurements now that both turntables have been spinning for longer than when I first measured. I was careful to use the same test record (I have a few samples of the 7" Feickert disc) and to start from the beginning of the side. I also placed the phone (with the app on it) in the same place. Both graphs show "bumpy rides"—measurements that look far worse than the ones I originally took and published. I repeated both twice and got the same results. In this series, the OMA's measurements were slightly better (absolute filtered deviation –0.6Hz/+1.0Hz) than the SAT's: –0.9Hz/+0.9Hz.

And then ...

A text message from Mr. Gomez and yet another set of measurements proved the fallibility of these Platterspeed results—that they should not be taken too seriously. I still think they're useful, but not everyone agrees: One manufacturer whose products I've given uniformly positive reviews to for more than 20 years refuses to offer any of his newest turntables because I use the Platterspeed app.

A day or so after his first text, Gomez texted again, giving me instructions on how to enter "service mode" to calibrate the XD-1's motor controller, which is similar to the one used in the Technics SP-10R. The purpose, he said, is to compensate for the optional vacuum platter's extra weight (a total weight of 33lb). Pressing and holding buttons causes the platter to spin at 100rpm for a few minutes, after which it reverts to 33 1/3 then stops. It takes about two minutes.

Before doing this, I played a few records with the Lyra Etna Lambda SL installed on the CF1-09Ti arm. The 'table sounded great, as described in the XD-1 review. Then I performed the calibration.

It was like giving the XD-1 a laxative. The improvement was not subtle: more liquidity, more transient precision, more spaciousness, and a greater sense of effortlessness. The test selection was "Stolen Moments" from the Acoustic Sounds/Verve series reissue of Oliver Nelson's The Blues and the Abstract Truth (Impulse A-5) featuring Evans, Chambers, Haynes, Dolphy, and Hubbard—no first names needed for those players.

Can this audible improvement be measured? Apparently not, because after the treatment, the SAT 'table measured somewhat worse than before (fig.3). But it sounded better. Way better.

This calibration suggestion arrived almost a year after the SAT review was published. I asked Mr. Gomez when he discovered it himself. "This morning," he said. Better late than never.

A Quick Cable Comparison
Speaking of measurements and audible improvements: Back in 2017, I posted tonearm cable files on AnalogPlanet and asked readers to choose their favorites. I ran a similar test last May. The sonic differences were obvious; they even included level changes. Some readers asked that the levels be normalized—but if the only variable is the cable swap, why would I alter the levels?

Earlier this week, I decided to do another cable test, this time with two phono cables: My Kuzma 4Point tonearm has a hard-wired connection from the cartridge pins to the RCA jacks. It also has an RCA-equipped junction box. Obviously, you can't use both simultaneously. The other cable was the RSX Beyond ($3150 for a 1m pair, footnote 4).

RSX was founded recently by XLO founder Roger Skoff. The top-of-the-line "Beyond" is fully shielded, double-grouned, and features "long crystal, ultra-pure Laboratory Grade copper," "Teflon variant-plus-air" dielectric, and ultralow-mass terminations, which are said to minimize self-inductance. The RSX line includes two other lower priced phono cables.

I played "Stolen Moments" from my newly flattened sample of the AP reissue of The Blues and the Abstract Truth, first with the hard-wired cables and then using the RSX cables via the junction box. I didn't change anything but the cables.

The result was surprising: With the Beyond cables, the music was louder—yes, louder . Significantly louder. To check that impression, I made a recording of the track with both cables and sent it to Editor Jim Austin; he looked at it in Adobe Audition (footnote 5). Then I repeated the measurement. According to Adobe Audition, the difference in volume was about 3.5 LUFS (Loudness Units Full Scale), essentially the same as 3.5dB. The difference was the same in both channels.

How can a phono cable make music louder? I consulted Jim Austin, who consulted Technical Editor John Atkinson. JA hit on the answer. The phono preamp was my CH Precision P1, and I was using it in current mode. Apparently, the RSX cable has a significantly lower resistance than the second run of Kuzma wire—and the cable resistance isn't tiny compared to the internal resistance of the phono cartridge. Less resistance, with the same electromotive force induced in the cartridge, means more current flows in the phono-cartridge loop.

More current in the phono loop means more voltage from the phono preamp.

To check this explanation, I did the same test again using the voltage-mode inputs on the phono preamp instead of the current-mode inputs. The Beyond cable still measured louder, but now the difference was very small—just 0.16 LUFS. I doubt many people could hear that.

Once I'd matched levels, I still heard a big difference. The sound was more open. Instrumental timbres remained the same.

The reverb behind the instruments was presented in greater relief, and the soundstage widened, with more air. Even the late Arnie Krueger would hear this.

One caution: The limited distance between the RCA plugs will make these cables incompatible with phono preamps with widely spaced input jacks.

I auditioned RSX's best power cords on the darTZeel amps a while back, and they produced a softer, less focused sound than the much more expensive AudioQuest Dragons. But in my system, the RSX Beyond phono cable produced a big improvement. They're well-shielded, too. This superlow-voltage link is among the most critical in an analog-centric hi-fi system.

Now that the electricity here has been optimized and the ground-hum issues are gone, I'm in a low-level cable swap mood—so expect more discussion about cables in future columns. I make no apologies.

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Footnote 4: RSX Technologies, 8211 Rochester Ave., Suite 102, Rancho Cucamonga, CA 91730. Tel: (909) 870-9292. Web: rsxtech.com

Footnote 5: I asked Mikey to record and send me the two test tracks. And then I asked him to do it again. And again. Each time, it came back the same: The recording made with the RSX cable was roughly 3.5 LUFS louder than the recording made with the hard-wired cable according to analytics in Adobe Audition. Both channels were affected equally.—Jim Austin