It’s one thing to mess up. It’s another thing altogether to make a blunder when you’re on record with the correct take already. But such is life. In a recent episode of the SoundStage! Audiophile Podcast, host Jorden Guth and I were chatting about gear, and he mentioned how much he loved the PSB Alpha iQ active speaker system, praising it for practically everything, but expressing some skepticism about the system’s phono input. “Will it give you the best phono stage? Will it give you the best reproduction of your records? I’m going to say probably not.”
To which I replied, “Why not?” and speculated that it’s probably the same phono input as my beloved NAD C 3050 integrated amp, which is practically perfect in terms of gain and RIAA equalization.
I’ll remind you, dear reader, that in my first editorial about vinyl for SoundStage! Access, over a year before I got my first turntable, I made this confident pronouncement: “If I do fall to the Dark Side . . . you can rest assured I’ll almost certainly be bringing a separate phono pre to the party. So I suppose, at the very least, I could say something about the relative merits of the onboard and outboard solutions.”
Look, I write a lot of words. I can’t be expected to remember all of them.
But why am I bringing all of this up now? It really comes down to one particularly precious record in my collection that is audibly warped but literally irreplaceable. I won’t dig too much into the specifics, but last summer I stopped by Village Green Records here in Montgomery and asked the proprietor Travis Harvey if he could order me a copy of King Gizzard & the Lizard Wizard’s amazing Butterfly 3000. He kindly reminded me of something I already knew: the album was pressed with a gazillion different packaging options, each in a different language, and there were only 500 to 1500 of each pressed. “It looks like I don’t have any say in which versions show up, so I’ll order two and you can just pick the one you like best. Any preferences?”
“I’d really love either the Japanese or Korean,” I said, “But I’m not holding my breath.”
Two weeks later, the two copies came in, and I had my choice between a Korean and (I think) a Hindi variant. I didn’t scrutinize the latter too closely, though, because the 나비 3000 version was everything I could have hoped for. What’s more, I got the blue pressing, which is the one I would have wanted had I realized there were three different colored options for all of Butterfly 3000’s variants. In short, I felt like I’d won the lottery.
Until I dropped a needle on it and realized the vinyl was warped, resulting in an audible periodic PHWOMP all the way through “Catching Smoke,” one of the best damned songs of the past ten years, no matter the band—which is all the more meaningful when you consider that it’s only the second-best track on this album.
Travis of course offered to replace it. But, as indicated above, this one is literally irreplaceable. He couldn’t pick which variant I would get in return, and if I ordered 나비 3000 online, there’s no telling which color I would get. Which is fine, I guess, because I already own the album on Blu-ray and CD. But still, it was a bummer to realize I own a record that’s basically eye candy and nothing more.
Months later, I was chatting with my SoundStage! colleague and friend Joseph Taylor about it, and his response sort of shocked me at first. “Have you tried a different phono preamp?”
Wait, what? It’s a warped record. I could see thinking a different type of stylus or a different tonearm might matter. But the preamp? This wasn’t a gain issue. Nor an EQ issue. My LP has a visible ripple in it. What could a different preamp do to help?
But it got me curious about what differences I might hear. When I first got my U-Turn Theory turntable, I compared its built-in Pluto 2 preamp to the phono stage of my NAD C 3050 and found the differences in levels and tonality to be so inconsequential that I stuck with the NAD’s phono stage, just so my wife wouldn’t have to remember a different input name if she wanted to play records when I’m not home.
But it was easy enough to swap some cables, press the button on the back of my Theory to engage the Pluto 2 preamp again, and slap 나비 3000 on my platter mat. What I heard when I did so was—unsurprisingly to any of you who’ve been into vinyl for a while and understand what a rumble filter is—no more periodic PHWOMP.
In my defense, these are the kinds of mistakes I’m going to have to make and learn from before I can do a competent review of phono preamps, which some of my readers have asked me to start doing. I wanted to accelerate that learning process, though, so I reached out to Joe, as well as my SoundStage! Access comrade Thom Moon and SoundStage! Ultra editor Jason Thorpe, and asked them to school me about all the things I didn’t even know that I didn’t know about phono preamps—or at least the stuff that I needed to keep front of mind once I felt comfortable doing a phono preamp review.
I started the conversation by interrogating Joe, since he’d been sharing his thoughts on the differences between a Schiit Mani 2 and his own Pro-Ject Phono Box S2 in private chats, and I wanted to dig more into the specifics. What differences was he actually hearing?
“One of the things I noticed about the Mani 2 right up front is that it’s much higher output than the Pro-Ject Phono Box S2 I’ve been using for a few years,” he said in our group video chat. “Higher output, but both of them are very low noise. You can crank them both, and you don’t hear that sort of background hash you can get with some phono stages. And for about a week or so, I was enjoying the Mani 2, but there was something bugging me about it. So I did some more direct comparisons and found that the Schiit is just a little too edgy on the treble side.
“Meanwhile, comparing the Pro-Ject to the very well-regarded phono stage in my NAD C 368 integrated amp, the Pro-Ject just has better channel separation, instruments are more focused and more clearly placed in the soundstage, and vocals are better centered and more forward—to me, overall, it’s more natural sounding.”
One thing I really wanted to hear from this group of old vinyl pros was a sort of triage list, which is a framing that helps me with all of my reviews, but one that’s different for different product categories. In other words, what problems should I listen for first? What’s my priority order for meaningful differences between phono preamps?
“First thing I’m listening for is the overall balance of the tonality,” Thom replied. “Does it sound natural? I’ve had the same experience as Joe with the Schiit Mani—I think it’s a little tipped-up at the high end.
“That’s why it’s important to me that I always have a reference. The phono stage in my Apt Holman preamp is the best phono stage I’ve ever heard in my life. Like some outboard phono stages, it has a selectable capacitance load for the cartridge. I’ve found that a lot of the newer cartridges don’t take a lot—they take basically 100pF to sound their best. Some of the older cartridges, they want to see a capacitance load of 350 to 400pF. And you throw that into a modern phono stage that’s looking for 100pF capacitance—that’s going to make a difference in the sound. Having adjustability allows you to find a setting that works best for your cartridge. You turn the capacitance up too high, and they lose all their high end. You turn it too low, and the highs are overly stressed.”
Not that such tweaky features are essential for the performance of a good phono stage, though, Thom said: “I tell you, one of the phono preamps that has impressed me most recently is the one that came baked into your turntable, Dennis—the U-Turn Pluto 2. I thought it sounded almost as good as [the phono stage of] my Apt Holman. It’s quiet. It’s simply a nice piece of electronics for nearly no money, and I think the U-Turn guys did a great job, as they do with everything they do. But it’s either on or off. There’s nothing to adjust. So I don’t think it’s necessary to get too hung up on features.”
But the rumble filter built into the Pluto 2 is a feature, I replied. Why doesn’t my NAD have it? Is that less common in built-in phono stages?
“You need a rumble filter, especially if you have full-range speakers,” Jason said, “but yeah, they’re rare in built-in phono stages.”
“There are exceptions,” Thom said. “There are even some, like the Apt, that have two-stage rumble filters. But another thing to consider when you’re hearing rumble like you heard with your warped record is the resonance of the arm and cartridge. In some cases, if the cartridge doesn’t quite fit the arm, and you get subsonic input, yeah—sometimes it’s that the arm and cartridge aren’t working together well. Some cartridges are meant to be paired with a medium-mass arm, or a high-mass arm. If I’m not mistaken, Jason, moving coils tend to favor a higher-mass arm, right?”
“It depends on the compliance,” Jason said. “I have a Goldring here that needs a low-mass arm. So it’s not consistent. If you have a low-compliance cartridge, you need a high-mass arm to control it. If you’ve got a high-compliance cartridge, you need a low-mass arm that’s not going to overpower it. It’s feature matching. It’s kinda like putting the right size of tire on your car. That’s why I think it’s important to say, in the course of a review, ‘I’m using this preamp with this cartridge on this turntable,’ because cartridges, turntables, and phono stages are so wildly different from each other that you can change one of those three and it’s almost like changing your speakers.”
If the arm and the cartridge and the turntable and the preamp all effectively work in concert as one system, though, what should I be listening for when reviewing just a preamp? I aimed that question at Jason specifically and asked for his own triage list of critical considerations, ranked from most to least important.
“Noise and hiss and interference are at the top of my list, since there are a lot of listening implications related to all that. Because you have a somewhat limited dynamic range with an LP to begin with, you don’t want the lowest-level details buried in the noise created by the preamp. Do you have to turn up the volume louder to hear those little details? That can screw you up by making the peaks a little too hot. Dynamic shading is a big thing that is [largely a consequence of signal-to-noise]. Those are issues you don’t have to attend to with a DAC.
“With moving-magnet cartridges, the gain is pretty much usually fixed at around 45dB, and that’s a lot of gain we’re talking about, but with moving coil, you’re now talking about 65dB to 75dB of gain. So with MM phono stages, you don’t have as much focus on noise control as you do with MC. But it’s also important to know that, with 45dB of gain, you can still pick up a ton of noise. So, to me, one of the most important things when checking out any phono stage is how much noise comes through. With MC, the differences are dramatic.
“Tonal balance is important, but that’s more flavoring. Most things other than tonal balance flow from noise. If it’s noisy, most of the stuff we care about in terms of hi-fi starts to fall apart.”
What about phono preamps that actively reduce noise, though, including pops and clicks? I have to admit, those have some appeal for me, and I’d love to review one, but not until I feel like I understand the category a little better than the average bear. I wondered what the old guard thought about such signal manipulation, though, especially since good pop/click filters operate best in the digital domain.
“I’ve only auditioned the ones from back in the ’70s, and they were less than successful. It was a nice idea, but the technology wasn’t there,” Thom said.
“My gut level is that I don’t trust them, because of what I heard with the older pieces. But then again, I don’t like anything that doctors the sound in a way I can’t control,” was Joe’s adorably curmudgeonly response.
Jason’s response shocked me, though. “Does it bug you when you’re listening, Dennis? Do the pops and clicks matter?”
Did my ears deceive me? Did he really ask me if bursts of noise seemingly randomly—or worse, completely predictably—peppered through my music affected my listening enjoyment? It sounded like such a genuine question, too. Was Jason having a stroke? Do Canadians have 911? Could I call for a wellness check?
That’s when I noticed that Thom and Joseph were leaning into their screens, very interested in my response. Because they, too, couldn’t fathom someone being bothered by pops and clicks.
Sensing my apoplexy, Joe chimed in, “I guess we just grew up with it, so it’s fine.”
After a bit of nervous laughter all the way around, Jason reached out with this olive branch: “Regarding the digitizing and noise filters, I would think that would make a great article, a great review, and I look forward to reading your impressions of one of those things. I wouldn’t use it as a reference, because it’s not something that 99 percent of people have. But I think when it comes to what you should be listening for, it’s the same as when you’re reviewing any piece of equipment, sound-quality-wise.”
And I guess, when you get right down to it, that’s going to look different for every reviewer. For me, I’m generally focused on the measurable, objective performance metrics that translate into listener preference. So with that in mind, I asked our measurements specialist, Diego Estan, what he pays attention to when measuring a phono stage—especially given that his measurements of the phono input of my NAD C 3050 were one determining factor in my procuring it as a reference.
“First, for me, is frequency response (RIAA accuracy). Frequency-response deviations are always number one for any audio product, since it’s the first thing you will hear. Next is signal-to-noise—always important in a phono preamp.
“There’s also the issue of overload margin, the ratio in dB between the reference level (say 5mV) and input level that causes clipping. (Actually, it’s the other way around, but you get it.) Looking through some of my measurements, that seems to range between 15 and 30dB at 1kHz, so there’s some variation. Because of RIAA, you always get lower values at low frequencies. For some cheap preamps, it’s just under 0dB at 20Hz. But it looks like cheap ones are usually 15dB at 1kHz, and with pricey ones you often see up to 30dB. So I guess the frequency content of the click or pop will really determine whether there is clipping. Since I’m not actually a vinyl guy, I don’t think I can speak to whether this matters in practice, though.”
That’s definitely something to keep an ear out for, even if I’m not reviewing preamps with built-in pop/click filters. And I don’t merely mean the overload margin issue, which I didn’t even know was a thing. I mean all of it.
More than anything, though, what these conversations have taught me is that there are so many moving pieces with vinyl (and I mean that both literally and figuratively) that maybe I just need to not worry about prioritizing the variables for the time being. Maybe I just need to jump in, expose myself to more phono preamps, and start to build my own triage list of what objective measures result in more subjectively pleasing performance. That, in some sense, goes against my nature as someone who believes in science. But so be it. It’s going to be a fun journey nonetheless.
And in a weird way, this whole conversation has conditioned me to see my warped copy of 나비 3000 as something of a blessing instead of a curse, because a phono preamp that renders it without the PHWOMPs in “Catching Smoke” is logically going to earn higher marks from me than one that transforms that physical distortion into an audible distraction.
. . . Dennis Burger
dennisb@soundstagenetwork.com
