Luminous Audio Technology's Remarkable Arion Phono Preamplifier

Much to the probable consternation of Luminous Audio Technology, I’ve sat on this MM/MC preamplifier review for more than six months. I probably could have literally sat on the Luminous Audio Arion too, so solidly is it constructed, but I didn’t.

Why the review delay? I wanted to be sure the $6395 Arion, from a relatively unknown, small company was reliable. Plus I was enjoying it way too much and wanted to be sure I completely understood why.

What’s Inside

The Arion is a single-ended two-stage design using cascoded/paralleled JFET topology in the input stage. The second stage is differential, optimized for the second stage’s higher signal levels. It’s also where RIAA equalization occurs.

All semi-conductors are carefully matched with JFET-based servos used only to guarantee balanced DC performance. This minimizes servo sonic “footprint”.

The unity gain based power supplies are typically used in laboratory-based electronics. Hum bucking C-core transformers feature noise-rejecting isolated primary and secondary windings. The + and – supplies use separate transformers.

Components include 1% metal film resistors and polypropylene film capacitors. Tight tolerance components are carefully selected for both signal purity and accurate RIAA tracking. Active devices include graded and carefully matched Toshiba JFETS, low-noise small signal transistors and Sanyo power transistors. Silver solder signal path connections are said to enhance sonic purity.

Luminous Audio’s designer, Mike Bettinger, brings 35 plus year’s experience to this project. He claims to have studied during that time many of the most esteemed “high end” designs in order to realize the Arion.

The critical circuit layout takes into consideration current loops and loads to control inter-stage interaction and minimize unintended feedback. Layout is at least as critical as is parts quality and matching.

The layout is on a four layer printed circuit board, with special care taken to meet the circuitry’s electrical demands. According to the company’s “white paper” the operating points of the active devices have been fine-tuned for their “electrical sweet spots” and individually fine-tuned by ear.

Single-ended or Balanced?

Here there is some controversy. Some designers claim phono cartridges are inherently “balanced” because there is no common ground, but, according to the Arion’s designer, a phono cartridge is not really “balanced”. So a balanced input, he avers, requires producing a pseudo-ground for the cartridge output and sending it through duplicate, carefully matched gain and EQ circuits to create a balanced output.

The Arion’s designer, Mike Bettinger, claims that the better (and correct) approach is to “successfully” reference the signal to the reference ground. Doing this correctly requires “maximum care in the layout and execution of the grounding circuit, which is an area of our expertise that (Luminous Audio has) thoroughly studied and researched.”

The Arion Puts “All of its Eggs in One Basket”

While separating the power supply from the signal processing circuitry has become commonplace in high performance designs, Luminous chose to put everything in one chassis, claiming that proper design and shielding results in equally low noise levels while saving the customer money. What’s more, there’s a single pair of RCA jacks, used for both MM and MC cartridges.

The quest for sonic purity and low noise does come at the expense of convenience. While a front panel mounted push button, using sub-miniature small-signal, gold alloy over silver latching relays (not subject to over time degradation), easily selects MM or MC, gain, adjusting capacitive and resistive loading requires more than the usual dip switch ease.

MC gain is factory-set, with owners able to choose from between 42dB and 67dB. Replacement of a feedback resistor by an “experienced technician” can change gain to 47,52,57,62, or 67dB. MC loading is somewhat easier to alter. The loading resistors are in sockets and so can easily be changed. MM capacitive load is even easier to adjust via internally mounted jumpers. Installed capacitors of 50pf, 100pf and 150pf allow for adjustments of between 50pf and 300pf in 50pf increments. Removing the top plate requires you to unscrew ten hex-head screws. Luminous wants you to work to tweak!

The back plate includes one set of Cardas RCA input and output jacks as well as a pair of “convenience” Neutrik XLR input jacks wired in parallel with the single ended input.

The very low five ohm output impedance guarantees minimal output cable interaction though Luminous does not recommend using unshielded twisted pair type interconnects.

The review sample was set for 62dB MC gain loaded at 100 ohms and 40dB MM. I can’t recall the capacitive loading figure but I didn’t run MM during the review because few, I think, will spend $6395 for a MM phono preamp. I feel it’s more a “convenience feature” though that probably insults some MM advocates. I apologize. However, were I going for a MM phono preamp, I’d go for a specialized one from companies like Graham Slee or Lejonklou (a review of the GAIO is upcoming).

Set Up, Use and Sound

As long as you’re willing to abide by the pre-set gain and loading (that you’ve chosen), all you have to do it plug in the inputs and outputs and flip the “on” switch adjacent to the IEC AC jack. The Arion default start-up is in “mute-MM”. Push the MM/MC button and you are ready to play.

If you listened to the second edition of Analogplanet Radio you’ve heard the Arion. Granted that’s after it’s been digitized at 96/24 and then “dumbed down” to CD resolution but what should be apparent are the Arion’s prodigious dynamic capabilities, it’s silent backdrops, it’s rhythmic authority, its deep bass capabilities and its essential sweetness and overall purity.

The Arion produces images that are superbly well-focused on a generously sized soundstage both in terms of width and depth. These terms get used and overused and I’m as guilty as anyone of using them. It would seem by now that soundstages were wide enough to fit into your next door neighbor’s house. I’m not suggesting that here.

What I’m saying is that like every truly great phono preamp the picture is not at all related to where the speakers sit. The stage develops in a space not limited by where the speakers are placed. Critical to producing this illusion is the image “edge definition”. If it’s too sharp, everything sounds “electronic”. If it’s too soft, everything turns to sap and mush.

Over time these problems become what you mostly hear and that’s obviously not good. It’s a fact of life in lesser (and less costly) gear and something designers have to carefully balance, which is why there is so much great budget gear—the good designers manage well the balancing act.

At this price point there should be little compromise though sometimes, designers attempting to extract every last bit of detail and resolution, push the envelope towards “analytical”. That is not the case with the Arion. It manages to be highly resolving on top, producing expansive high frequencies and clean, generous high frequency transients without sounding analytical or “crunchy”, though some listeners might prefer more air and slightly sharper transients.

I was satisfied with the high frequency transient response, and if the slightly soft top was the price paid to achieve the rich, velvet-gloved the midrange, it is well worth it. Female voices and strings sounded full-bodied, rich and sonorous. If you think “solid state equals thin”, the Arion (once fully broken in) should quickly change your mind.

The bottom was taut, well extended and dug deep, but not to the point where it sounded over-damped and electronic. Bass textures, whether acoustic stand-up or plug-in electric, were well developed and supple.

My reference Ypsilon VPS-100 is back in Greece after five years of heavy use for a series of updates and re-tubing. It turns out that after five years the military metal jacket tubes still meet new specs, which is amazing, but more amazing is that the Arion, while not the equal of the far more costly Ypsilon has more than adequately filled much of the void.

The Arion produced a different sound, one that’s somewhat less midrange-lush and expansive overall, but its bottom end grip and ability to unravel inner detail—as heard quite easily during the Roxy Box Set coverage—resulted in another kind of intensely pleasurable listening that was 100% free of distracting electronic artifacts.

If you like your picture holographic, you’ll love the Arion. Its ability to produce solid, full-bodied images on a three dimensional soundstage were among its most compelling qualities.

I’ve got some Electric Recording Company reviews underway including one reissue of a piano recital by Magda Tagliaferro (ERC 012) an obscure (to me) pianist born in Brazil of French parents. The album is a reissue of an original 1960 issue on the French Ducretet-Thomson label, on which she performs compositions by De Falla, Granados, Albeniz, and Villa-Lobos. The recording is spectacularly natural and dynamic. The only thing more difficult than recoding a piano well is playing it back well (not to mention playing it well!).

The Arion’s attack was slightly on the soft side compared to the far more expensive Ypsilon’s, (shipped back shortly after the audition), the sustain was somewhat less generous than the tubed unit’s as was the decay but the Arion’s stunning transparency more than made up and the overall presentation and the sense of being in the space where the artists played the piano was palpable.

I’m using the Arion to compare originals with the Simon and Garfunkel box set reissues and I feel fully confident that its resolving abilities more than capable of producing accurate comparison results.

I auditioned the Arion using, among other cartridges, the Lyra Atlas, which has a generous .45mV output, and the Ortofon Anna, which has a far lower output of .2mV. The Arion handled both equally well. Clearly it’s capable of dealing with both ultra-low and relatively high output moving coil cartridges. Interestingly, while the Anna’s 6 ohm internal impedance would suggest 100 ohm loading is too high and might produce unwanted brightness, that wasn’t the case.

Perhaps because of the Arion’s overall sweetness and lack of upper frequency etchiness, I felt comfortable with 100 ohm loading with every cartridge I tried.

Conclusion

Luminous Audio Technology’s Arion is a superbly engineered and built solid-state phono preamplifier that manages high resolution, outstanding transparency, impressive bottom end extension and grip, a velvety midrange, and an overall tonal neutrality that makes it easy to recommend. Most importantly, top to bottom, it all holds together to produce a unified sonic statement. It has no fundamental weaknesses but were I to assign any sonic personality to it that might be seen as a negative it would be that it’s perhaps a little too sweet on top and so misses that last bit of air and high frequency shimmer and “crunch”.

However, the trade-off is well-worth it to get the unusually rich (for a solid state design), but not ripe midrange. While the unit came well broken in, I felt it only improved with time, especially in terms of midrange fill. It never sounded thin and/or threadbare, but the midrange definitely filled in over time.

The Arion reminded me somewhat of the far less expensive (and not as accomplished, though still an amazing value) Liberty B2B designed by Peter Noerbaek, which also uses Toshiba JFETs. It too has a sweet yet well-detailed overall sound, though not on a scale as grand as the Arion’s.

I don’t know if Luminous offers a money back guarantee, but if you’ve got a budget for a phono preamplifier of around $6500, the Luminous Audio Arion should definitely be on your “to hear” list. I’ve enjoyed the more than eight months I’ve had it in my audio system and if you’ve listened to this week’s radio show, I’m sure you’ve enjoyed it as well.

The Specs:

COMPANY INFO
Luminous Audio Technology
1312N Parham Rd.
Richmond, VA 23229
tim@luminousaudio.com
(804) 741-5826

COMMENTS
Billf's picture

I've had one of their Axiom passive preamps that I use with my turntable and EAR preamp. It sounds terrific and is beautifully made.

Ortofan's picture

...a "cascaded/paralleled JFET topology" - or might it instead be a cascoded/paralleled JFET topology?

If you didn't even listen to the MM input, can you truly be confident in recommending that a Grahan Slee unit - or anything else - would be a better choice?

One might think that the manufacturer would be insulted that you sat on the review for six months without completely evaluating all of the product's functionality.

Michael Fremer's picture
Yes cascoded....as for MM, I think it makes more sense to buy a dedicated MM phono preamp and then later, add an SUT or "head amp" rather than spending up front for something you might not use for quite some time. The MM section here might be better than one of the dedicated MM phono preamps. I just don't think it makes sense from a cost point of view.
Ortofan's picture

...two-stage topology, it's not clear if the first stage is a head amp used only with MC/low-output cartridges. Some two-stage designs split the total gain between the two stages, regardless of cartridge type, with the first stage gain being adjustable to accommodate lower or higher output cartridges - so the output from any type of cartridge always passes through both stages. Would you happen to know which way the Arion is configured?

Michael Fremer's picture
The only way to adjust gain is by changing a feedback resistor...however, I will ask the designer...
Michael Bettinger's picture

Actually changing the gain is as simple as changing the loading. It is controlled by a single resistor in the feedback loop of the first stage and this resistor is installed in a pair of sockets. There is a chart in the owner's manual that indicates which value to use for the gain setting your cartridge requires. There is also an image to refer to.

Mike Bettinger

Michael Bettinger's picture

The first stage is simply a gain stage. The switching between MM/MC sets the gain at either 20db or 40db and is internally adjustable. The second stage has a set 22db of gain. Both MM and MC cartridges pass through both stages.

Mike

Ortofan's picture

It wasn't quite clear whether or not the MC pre-preamp was a separate gain stage that would remain unused with a MM cartridge.

The specifications shown above specify the frequency response as 20Hz-20kHz +/-0.2dB. Is there a subsonic/infrasonic filter included? If so, what is the cutoff frequency and slope? If not, what is your rationale for not providing one?

Michael Bettinger's picture

There is no low frequency roll off. Because of its price point, I assumed that the preamp would be paired with good turntables as a starting point. And, while the situations that would benefit from a low frequency roll off are many, I have determined that the grounding network that the cartridge sees has a pronounced effect on the system's susceptibility to low frequency resonances and acoustic feedback picked up by the turntable. The benefit of the extended response, especially with the resolution that the JFETS provide, is a sense of air, speed and coherency in the bass that I like.

Michael Bettinger's picture

Because the MM and MC cartridges see the same circuitry, the performance between the two is consistent. Our attention to detail in the layout and the grounding of the circuitry makes the input of the preamp less sensitive to variations in the cartridge that drives it. The performance with both is excellent.
We were not at all concerned with the length of time Michael had the preamp. Sure, we were anxious to get his thoughts, but we didn't want to rush him through the review. We're pleased he put the time and attention into it that he did - and very pleased he enjoyed it.