Gramophone Dreams

When I grew out of shopping with mom, I began fitting pipe with my father and making hay every June with my uncles. Before I drove cars, I drove tractors in Wisconsin. The fields with the cut hay were about a half-mile from the shed where the tractors were stored, which meant I drove on the paved road dragging an empty wood wagon behind me. In one of the upper gears, with the throttle partway open, I'd space out listening to the deep-volumed rap-rap-rap of power issuing from the tractor's exhaust stack while making my way slowly up and down the rolling hills. The tractor's mass was so large, its torque so great, its gearing so stiff that its speed never seemed to waver. This sensation of inertia produced a calming, trance-inducing effect that I'm feeling once again while playing records on the Lenco. Now I'm wondering if this tangible sense of inertia is what makes idler drives so devotion-worthy.

Alone at night, I swear I can sometimes feel the Lenco's geared-down idler exerting its forward pressure on the platter's rotation. This sensation of pressure was easiest to observe on quiet solo piano and chamber music recordings. This is something I don't remember noticing with low-torque direct drives, or generic belt drives, where each belt-platter combination affects the sound differently, depending on how heavy the platter is and how many horses are pulling its belt. When a stylus is traversing the groove and a loud passage comes, the heavier platter will slow down less, but it will always slow down a little if the torque is insufficient for a fast response.

I know the reality of these spinning-platter epiphenomena is debatable and that my experiences of them are borderline subliminal. But if you've ever driven a tractor on blacktop, you'll know what I'm talking about.

I'm sitting here watching myself falling into a rabbit hole named Lenco that feels a lot like one of those project cars of my youth, a time when I could hang over a fender for hours and break-dance on a creeper. But for geezer Herb, this L75 is the right size, shape, and weight and requires the right size tools for me to pretend I'm working on a project car—without the oil-stained garage floor, sore back, or barked knuckles. Maybe I'll try hot-rodding it with a tonearm swap next.

PrimaLuna's EVO 100 phono stage
As I experimented with cartridges on the Lenco, I was reminded how almost all commercially available phono stages use either a step-up transformer or a JFET at the input of their moving coil circuit. Almost none of the world's tubed phono stages have a tube at the moving coil input. One of those very few, PrimaLuna's new EVO 100 (footnote 3), was in a box in my hallway begging to be connected to my Lenco-Denon DL-103 setup.

As I unpacked the heavy, triple-boxed PrimaLuna, I thought how few tube phono preamps have tube rectification and how even fewer have tube-regulated power supplies.

PrimaLuna's $3695 EVO 100 features all these deluxe tube accoutrements: dual-mono 5AR4 tube rectification; dual-mono choke-input EL34-regulated power supplies; and two 12AX7 twin triodes per channel for the RIAA stage and one 6922 twin triode per channel for its moving coil input stage, which sits in its own shielded, cushioned box at the back of the preamp, just above the input jacks.

I'm always saying how everything sounds like what it's made of, and how this applies to vacuum tubes and power supplies as much as it does to transformers, resistors, capacitors, or wire. The more tubes there are in an amplifier's circuitry, the more likely it will sound liquid and radiant—like tubes. The bigger and more responsive its power supply, the more the amplifier will weigh and the more punch, liquidity, depth, and dimensionality it will deliver.

I was intrigued and excited to audition PrimaLuna's EVO 100 phono preamp because the last time I experienced a tubed input for a moving coil was in the early 1990s when I built a few Arthur Loesch phono stages that used a separate power transformer, tube rectifier, and choke-input, high-capacitance power supply for each of its six WE417A tubes.

PrimaLuna's EVO 100 takes the Loesch preamp's extremism even further. It is built on an octal-tube–rectified, power-tube–regulated power supply. I wanted to see how that combination of expensive-to-implement features would contribute to the sound of my system using low-output cartridges.

The EVO 100 looks like a narrower version of the company's $5295 EVO 400 preamplifier (11" vs 15" wide), which I reviewed in June 2019. The EVO 100 weighs 27.9lb. Together, these two components make a unique 81.9lb, 18-tube, $8999 preamp/phono stage combo that was, by virtue of these engineering choices, guaranteed to sound different than any previous phono amplification I've used since I started writing for Stereophile.

When I wrote, a few paragraphs ago, that "the more tubes there are in an amplifier's circuitry, the more it will sound liquid and radiant—like tubes," I did not mean to imply that more tubes automatically mean better sound. In fact, I was hinting that "too much of a good thing" might apply here: 18 tubes in front of a tubed power amplifier might be too many. The reason I've never favored tubes or transistors is that too many of either is like too much butter or salt. Historically, I've preferred a transistor preamp with a tube-based power amp, or vice-versa, depending on the speakers. I call this "yin-yang-ing suppleness" because I don't like my music to sound tubey or transistory.

When I first heard about it, I began wondering whether the EVO 100 could somehow become my new reference phono stage. Despite having only one input (a major defect at this price point), it has done that. Loading and gain are selectable from the front panel. Its five MC loading choices—50, 100, 200, 500, and 1000 ohms—are well-chosen. The gain choices—40dB for MM, 52, 56, and 60dB for MC—make it convenient for someone who changes cartridges often, as I do. I wish there was 10dB more gain, but that might be pushing the noise factor too far. In concert, these loading and gain choices should properly serve any moving coil cartridge with an output of 0.3mV to 0.6mV without overloading on loud transients (footnote 3).

Tube forest wonderland: The minute I got it, I connected up the EVO 100. I tried it with the Denon DL-103 on the Lenco and with EMT's JSD 6 moving coil cartridge and EMT 912 tonearm on my Dr. Feickert Blackbird turntable.

The results were disappointing. I thought the PrimaLuna made both cartridges sound off, or at least not like they sounded with my Tavish or SunValley preamps. But PrimaLuna importer Kevin Deal at Upscale Audio had already warned me that the EVO needs three days powered on to sound its best, so I reinstalled the SunValley equalizer and left the EVO 100 plugged in and turned on for seven days. After really digging the Denon DL-103 with the 50 ohm JFET load on the EQ1616D, I was curious to see how the Denon would respond to a "tube" 50 ohm load like the one on the PrimaLuna. Dang me if the fully warmed-up EVO didn't up the 103's dynamics and vividosity by at least 50%. I've loaded the DL-103 in every imaginable way, and I still prefer it with my EMIA SUT, but the EVO 100 at 50 ohms sounded surprisingly musical and engaging.

Then I played Duke Ellington's Blues in Orbit (Columbia MOVLP 443) with EMT's JSD 6 into the EVO 100, loaded at 200 ohms. I've heard that record a thousand times, on some of the world's most expensive turntables, sporting $10k+ cartridges, and I can't say it ever sounded bigger, bolder, richer, faster, or more thrilling than it did through PrimaLuna's all-tube phono stage. The PrimaLuna completely eliminated the JSD 6's tendency to sound tight and analytical, giving me instead a cartridge–phono stage combination that was both lush and heart-pounding fun.

Because the tube input EVO 100 sounds so different from generic JFET stages, I fear many audiophiles will hear it once, pass judgment, and move on. They'd be missing the cake and ice cream at the end of the party. I don't exactly know what is changing while an amp is cooking for days, but I do know that Kevin Deal was right: The EVO 100 needs to be left on 24/7 for at least three days to sound as bold and magic-mushroom wonderous as what I just experienced with the EMT JSD 6. The JSD 6–EVO 100 combo produced room-filling, big-wave power and sublime clarity. It made me feel like I could see to the bottom of a deep crater lake filled with perfectly clear water.

It's impossible to be sure, but I attribute this largely to the EVO's tube-rectified, tube-regulated power supply. It takes more than a giant power transformer and a ton of capacitance to make a responsive power supply that doesn't lose small-signal data and generalize big-signal data.

That much deep-water clarity and big-wave power production felt new to my senses. The sound character was all-tube in a way I was uncomfortable with at first. But PrimaLuna's uncompromised power supply and high-transconductance 6922 tubes at its MC input forced me to recalibrate my JFET/SUT–informed taste to accommodate a radically different, new type of sound I had not previously imagined. Like the Heretic AD614 speakers, which thrill me more with each passing day, the EVO 100 is a revelation, and, for the moment at least, my new reference phono stage. But please remember, neither of these products were designed to sound like anything we've ever heard before.

If it ain't one thing, it's the mother: To keep my tastes evolving, I try to listen with a child's mind, wherein I don't care who made the audio equipment, when it was made, how much it costs, or how it measures. I only care if it looks cool, sounds like real humans making music, and, most importantly, if I feel pleasure and contentment while it's playing my records. The Gen-X Lenco L75 with the baby boomer Denon DL-103 and PrimaLuna's brand-new, all-tube EVO 100 excelled at all these things.

My plan for next month: to compare PrimaLuna's EVO 100 to Mobile Fidelity's new MasterPhono solid state phono stage.

---

Footnote 3: PrimaLuna USA/Upscale Distribution, 1712 Corrigan Ct., La Verne, CA 91750. Tel: (909) 310-8540. Email: info@upscaleaudio.com Web: upscaledistribution.com

Footnote 4: See hifinews.com/content/primaluna-evo-100-tube-phono-preamplifier-making-headroom.