Written by Oliver Amnuayphol
Category: Full-Length Equipment Reviews
Created: 01 February 2019
When I started out in audio, hi-fi gear from Boulder Amplifiers always seemed like so much mythical unobtanium to this perennially cash-strapped, wide-eyed teen. It wasn’t just the five-figure prices that put their gear out of my reach: No dealers in my neck of the woods carried the line, thereby making auditioning impossible. Still, neither of those high hurdles kept me from salivating over Boulder’s visually arresting, no-compromise wares, including its now legendary, dual-chassis, model 2008 phono preamplifier, which, on its debut almost 20 years ago, sold for the almost unheard-of sum of $29,000 USD.
Design advancements have since resulted in Boulder creating the single-chassis 1008 phono stage, claimed to offer performance improvements over its predecessor for $16,000, or little more than half the price. And while the folks at Boulder continue to push the performance envelope with their flagship models, they’ve also recently produced a relatively affordable, solid-state phono preamplifier for mere mortals such as I: the 508.
With a retail price of $5000, the 508 is Boulder’s lowest-priced audio component yet. In fact, it looks to be the first of an all-new 500 series of more affordable models. It’s also a departure from Boulder’s cost-no-object designs in at least one other aspect: While the 1008 is outfitted with flexible cartridge loading and setup options, selectable equalization curves, and a host of other conveniences, the 508 is almost completely devoid of such features, and has a total of three user-selectable controls: a rear-mounted toggle switch to select moving-magnet or moving-coil settings for its single pair of balanced inputs (XLR), and, on the front panel, a Power toggle and a Mute button.
But oh, what beautiful switches these are. Boulder products have always been known for their unsurpassed build quality, and the 508 is no exception. Indeed, impeccable craftsmanship is evident throughout, and the beautifully machined controls feel substantially solid and smooth in movement and touch. Those familiar with and fond of Boulder’s signature satin finishes will appreciate the same gorgeously brushed, sanded, bead-blasted, and anodized process applied to the 508’s casework. Said case is also the chassis, machined at Boulder’s in-house CNC center from a solid billet of 6061-T6 aluminum. Sized to maximize efficiency and minimize the wastage of metal, its dimensions are just 11.5”W x 2.3”H x 9.5”D. The 508’s 11.5-pound weight feels surprisingly and reassuringly hefty for so small a component, and its overall shape and appearance are models of clean lines and efficient design.
A look within reveals that Boulder has put similar efforts into the 508’s internal design efficiency and construction. The self-regulating power supply is partitioned off in its own subsection, to minimize noise and potential interference with the analog section. Surface-mount components populate the tidy analog board, and the entire design makes such efficient use of PCB real estate that there are hardly any wires to be seen. This virtually eliminates any parasitic capacitances and lead inductances, and the fully balanced circuitry should help further reduce noise and maximize resolution. As such, the analog signals terminate in 100-ohm XLR connectors; XLR-to-RCA adapters are supplied for the input side. Specifications for the MM/MC switch are: MM, 47k ohms input impedance and 44dB of gain; MC, 1000 ohms impedance, 70dB of gain.
Given the 508’s sparseness of features, setup was easy-peasy: Use XLR-to-RCA adapters if required; flip the switch to MM or MC, depending on the cartridge; and toggle the power switch to On. After about 100 hours of run-in, for a test run I cued up Amy Winehouse’s Back to Black (LP, Universal Republic 0008994). With its mildly spitty midrange, slightly etched highs, and dry, heavily processed sound, this album is a great tool for revealing a component’s colorations or frequency-related deficiencies: too hot, and the record is unlistenable; too warm, and it’s entirely uninvolving. The Boulder 508 handled this LP with aplomb, sounding distinctly honest, uncolored, and musically engaging without editorializing on its sound.
The Boulder coupled this neutrality with what I consider a key but often overlooked essential ensuring the listener’s involvement in the music: It was happy being a sonic chameleon, never calling attention to itself. Instead of goosing up the highs or lows, or generating other types of whiz-bang sonic fireworks, the hi-fi gear I’m usually most fond of does its best work by letting the music speak for itself and letting me listen into the sound.
And so it went with this hefty little brick of a Boulder: I reveled in music for many fatigue-free hours on end, unworried about gross sonic aberrations or bunions because they didn’t exist. Through the 508, well-recorded albums featuring strings and a woman’s voice, such as Billie Holiday’s achingly beautiful Lady in Satin (2 45rpm LPs, Columbia/Classic CS 8048-45), sounded as natural and sonically complete as could be. Holiday’s well-worn voice came across with all its depth and complexity intact, and the strings of Ray Ellis’s orchestra sounded simply like strings, believably brilliant and highly textured with no mechanical hardness or glare. This sort of timbral naturalness is something solid-state gear often struggles to get right; the Boulder 508 nailed it.
Equally as impressive as the Boulder’s neutrality was its supreme silence: In terms of background and self-noise, the 508 is the quietest phono stage to have passed through my system. Small-scale recordings, such as a reissue of Leonid Kogan and Elisabeth Gilels’s 1964 disc of sonatas for two violins by Leclaire, Telemann, and Ysaÿe (LP, EMI SAX 2531/Electric Recording Company ERC008), let me hear how well the 508’s noiselessness allowed delicately nuanced passages to bloom from silence with greater microdynamic detail and subtlety. If you’re looking for a phono stage with which you can fully enjoy more intimate music and/or music at lower volume levels, the Boulder 508 should be right up your alley.
That’s not to say the 508 couldn’t do macrodynamics as well: Given the right source material, it was capable of blowing down the walls. In “Malletoba Spank,” from Duke Ellington’s Jazz Party in Stereo (LP, Columbia/Classic CS 8127), the Boulder deftly moved from forte to fortississimo (fff) with ease, delivering hair-raising doses of explosive impact and drama when called for. While not quite as dynamically expressive as the best phono stages I’ve heard, the 508 was still plenty satisfying in this regard, and would likely exceed the capabilities of most systems it’s likely to be paired with.
The 508 also showed itself to be fundamentally accurate in terms of rhythm and timing. During the horn section’s repeated phrase in “Just Friends,” from Amy Winehouse’s Black to Black, the 508 did a fine job of keeping the various instruments properly lined up in lockstep with the reggae-style backbeat, accentuating the song’s toe-tapping, dance-friendly groove. While the Boulder’s reproduction of this track wasn’t the most propulsive I’ve heard, it was certainly believable in this regard, and never committed any unnatural errors or left me wanting more rhythmic insistence.
With a component as evenhanded as the 508, it’s hard to point out many frequency-related characteristics, except to say that the sort of musical neutrality at which the Boulder excelled extended to its sonic qualities as well. The Boulder 508 possessed an overall top-to-bottom coherence that seemed almost perfectly judged for how fundamentally right it sounds.
Still, the 508’s sound had some highlights. At the low end of the audioband, for example, the heavily accentuated kick drum in “My Queen Is Nanny of the Maroons,” from Sons of Kemet’s Your Queen Is a Reptile (LP, Impulse! 6736432), thumped with a tactility, tautness, and definition that made its sound as clean in its retrieval of detail as it was effortless in its delivery of amplitude. Here, the 508 also clearly and articulately conveyed the tonal richness, pitch definition, and blatty growl of Theon Cross’s tuba in the ostinato line that underpins this track. The sheer amount of bass information present in “Nanny of the Maroons” makes it easy to hear when a component is overenthusiastic in the low end and turns it into a muddled, indistinct mess. Not so the Boulder 508: It did nothing to overblow the quantity of bass or diminish its quality; instead, it communicated precisely what was recorded.
With a good handle on the Boulder 508’s sound, I decided to compare it with Parasound’s Halo JC 3 Jr. phono stage ($1500). Given that the 508 costs more than three times the Halo’s price, this pairing might appear lopsided. The two products are also quite different in design: The Boulder eschews all but the most essential features, while the Parasound includes variable MC impedance, selectable gain options, and a Mono switch. Still, I was confident the JC 3 Jr. would hold its own — my experience of it had suggested that it offers exceptional sound quality for the price, and comparing it with the Boulder made for an interesting yet reaffirming exercise.
Playing Eric Dolphy’s Out to Lunch! (LP, Blue Note/Music Matters MMBST-84163) reminded me why I developed such a fondness for the Parasound in the first place: Its even spectral balance, near absence of coloration, and agnostic musicality made it easy to just kick back and enjoy tunes, regardless of recording quality or musical genre. But when I listened to the same album through the Boulder, everything that’s good about the Parasound got even better: Bass tightened up, and gained more clarity and tactile presence; middle registers sounded more lifelike and revealed more detail; and treble shimmered with greater refinement and delicacy.
In fact, it was in the highs that the Boulder 508 distanced itself from the junior-priced Jr.: It pulled more natural decay and harmonic development from the bells and vibraphone in Dolphy’s “Hat and Beard,” making these instruments sound more complete and realistic. The Sons of Kemet’s “My Queen Is Nanny of the Maroons” also sounded better through the Boulder: Cymbals rang truer, with greater realism, and the 508 reproduced more pellucid purity and retrieved more microdetail, especially in terms of attacks, sustains, and decays.
Another area in which the Boulder got the nod was through the upper bass and lower midrange. Through the 508, instruments with rich harmonic complexity, such as John Roney’s piano, or Bobby Hutcherson’s vibraphone on Out to Lunch!, sounded fuller and more harmonically developed; the Parasound’s sound here was mildly diminished in comparison, robbing these instruments of some of their realism and scale. The Boulder also conveyed more realism in the texture and touch of Richard Davis’s unique thumps on the body of his double bass, and his plucking and bowing; ditto Dolphy’s alto saxophone, which had more believable solidity and presence. While these differences weren’t large overall, the Boulder proved itself the more natural- and complete-sounding phono preamp.
The Boulder 508 also earned top marks for spatial effects. With the Sons of Kemet album, or Fritz Reiner and the Chicago Symphony Orchestra’s recording of Rimsky-Korsakov’s densely scored Scheherazade (LP, RCA Living Stereo LSC-2446/Analogue Productions AAPC-2446), both phono stages developed realistic and well-defined soundstages, but the Boulder’s bloomed into my room with greater width and depth. Its imaging was also more palpable and holographic, and thus believable, and outlines of instruments’ aural images were more vividly drawn and sharply rendered. Its reproduction of envelopes of air and space around individual instruments also seemed more realistically atmospheric.
When I’d finished all my comparisons, I was surprised at how similar the two phono stages sounded — certainly more alike than different overall. It made revisiting the inexpensive Parasound Halo JC 3 Jr. a welcome experience. Still, the Boulder 508 was the clear winner. It offered across-the-board improvements in sound quality over the Parasound Halo, and that’s as it should be. But given the Halo’s price, this comparison takes nothing away from its performance, and instead puts the onus on the Boulder to prove that it’s worth more than three times the Parasound’s price — which it did. Those looking to take a couple of big steps up the sound-quality ladder from a phono preamp costing $1000-$2000 should hear clear and worthwhile improvements in the Boulder 508.
Being primarily a tube guy, I was a bit surprised at how much I enjoyed the Boulder 508, which won me over with its well-considered design and highly refined sound. It’s undoubtedly the most neutral phono stage I’ve ever used, and its cleanly rendered coherence, fine expression of dynamics, and convincing rhythm and timing help make it a component whose overall sound quality is greater than the sum of its parts. That it’s able to deliver this level of refinement without erring on the side of sterility or blunted musicality is a testament to Boulder’s engineering expertise and excellence of execution; that Boulder can wrap it up in such a gorgeous and finely finished enclosure for $5000 only underlines that testament.
This combination of attributes makes the Boulder 508 unique among phono preamplifiers in its price range; that alone should make this little wonder a tantalizing prospect for vinyl-loving audiophiles. I’m hard-pressed to think of any caveats other than the 508’s lack of flexibility. But to those looking for a straightforward, fuss-free phono preamplifier that prioritizes sound quality, I say put the Boulder 508 at the very top of your audition list: It’s my top choice in a solid-state phono stage at or near $5000.
. . . Oliver Amnuayphol
Loudspeakers — Aperion Audio Verus II Grand, Living Voice Avatar
Integrated amplifiers — Audio Note L3 El84 with Signature upgrades and C-core transformers, modified; Marantz PM-KI Pearl
Phono preamplifier — Parasound Halo JC 3 Jr.
Step-up transformer — Custom-made Sowter Magnetics 9570 (1:10)
Sources — Rega Research RP8 turntable, Lyra Delos cartridge
Interconnects — Custom single-core, copper coaxial (RCA); Blue Jeans Cable LC-1; Wireworld Starlight 7 (USB, coaxial)
Power cords — Wireworld Aurora 5.2 and Electra 5.2
Speaker cables — Tellurium Q Ultra Black, Wireworld Oasis 6
Accessories — Music Hall WCS-3 record cleaner, Clearaudio stylus cleaner, Mobile Fidelity Sound Lab record brushes
Boulder Amplifiers 508 Phono Stage
Price: $5000 USD.
Warranty: Five years parts and labor.
255 S. Taylor Avenue
Louisville, CO 80027
Phone: (303) 449-8220