
When talking ideals in amplification, or any piece of hifi for that matter, my pinnacle is well balanced.
Standing somewhere above well balanced is beauty, a kind of beauty in reproduction that makes it unavoidably clear that the sounds that comprise music can be things of beauty that touch us well beyond ears and brain, transforming sounds and music into exciters of heartstrings, vibrating our core, connecting us to something bigger than just us. We become one with the music in that magic moment.
During my nearly 2 month time with the BorderPatrol S20EXD, in a couple different system settings on both sides of the Barn, it consistently delighted with this kind of beauty beyond well balanced, connecting me to my music well beyond some sober intellectual exercise right into the heart of the matter.
And let’s put a stake through the heart of that decades old tired ‘300Bs sound soft and warm and bloated’ myth—the BorderPatrol S20EXD does power, control, scale, and dynamics without any need to talk about tubes or solid state. Heck, I’ve heard less convincing power, control, scale, and dynamics from some solid state amps. Of course we need to be mindful of the speakers we pair with our amplifiers but this reality applies universally. Or to put it another way, there’s no such thing as The Perfect Amp for any and every speaker. Or another way still, I’m generally not a fan of speakers that demand more current to bring them to life than Frankenstein’s monster.
The dual mono, point-to-point wired BorderPatrol S20EXD employs interstage transformers to couple the 2x NOS Sylvania 6DR7 double triode input tubes to the Western Electric 300B output tubes, which run in parallel single-ended mode, 2 per channel, outputting 18 Class A Watts. Rarely used today, interstage transformers have significant technical and sonic benefits compared to the much more common capacitor coupling, according to BorderPatrol. The ins and outs on the S20EXD reside behind the tubes and transformers mounted to the top plate and include 4 and 8 Ohm speaker outputs and a pair of single-ended RCA inputs. The review unit came with an optional volume control, perfect for a one source system. There are two captive cords coming out the back of the S20 that attach to the included external power supplies.
BorderPatrol recommends mating the S20 with “loudspeakers of >90dB efficiency with an impedance characteristic that is relatively uniform and does not drop below 4 Ohms”. Frankenstein’s monster need not apply.
BorderPatrol has been building tube amplifiers and power supplies since the mid 1990s and their first product, the Border Patrol PSU, was designed to be used with tube amplifiers so it should come as no surprise that the S20EXD comes with a pair, one per channel, of massive external power supplies, weighing 35lbs a piece.
Each PSU contains:
1x Mullard GZ37/CV378 full wave rectifier in the 300B high voltage supply
1x EZ80 full wave rectifier in the input driver stage high voltage supply
1x EZ80 full wave rectifier in the 300B negative bias supply.
From BorderPatrol:
Each PSU contains three independent tube rectified, choke input filter high voltage supplies to independently feed the 300B’s, the input/driver tubes and the negative bias supply, together with filament supplies for the 300B’s and small signal tubes. The use of choke input filtering is a critical difference and is unique to BorderPatrol power amplifiers.
Gary Dews, Mr. BorderPatrol, delivered the review sample and performed the initial tube biasing for the 300Bs. This relatively simple procedure is described in detail in the included manual and requires a DC Voltmeter, a screwdriver, and a few minutes of your time. The Bias adjustment screws are located on the S20’s underside along with a pair of Hum Cancelling Screws used to dial out any hum from the 300Bs. The review units [footnote 1] were silent running even with my ear next the drivers.
The amp proper weighs in at 55 lbs. so we’re looking at 125 lbs. of amp + power supplies all in. The S20’s chassis, a combination of wood, black powder coated metal, and exposed transformers looked right at home in the Barn and put on quite the light show into the wee hours.
I paired the BorderPatrol with the review Living Voice R80 OBX (more info) that offer a 92dB (2.83v @1m) sensitivity with a 6 Ohm nominal and 4.5 Ohm minimum impedance, and the Barn resident DeVore Fidelity O/96 (review) and their 96 dB/W/M sensitivity and 10 Ohm impedance. Digital duties were handled by the Mola Mola Tambaqui (review) on the Barn’s B-Side and the Barn resident Grimm MU1 (review)/totaldac d1-unity (review) super combo on the A-Side. All cabling in the Barn is from AudioQuest including their ThunderBird and FireBird ICs and ThunderBird Zero and Robin Hood Speaker Cables (see full Barn and system details).
I know you know I know the DeVore O/96 as well as anyone can know a pair of speakers, having lived with my pair for years and run them with too many partners to count. When an amp lights them up in a special way, as a few have done over the years, I know it with the same kind of certainty that leads me to the sink for a glass of water. And the BorderPatrol S20EXD lit up the O/96 with a very special magic, the kind of music reproduction that transcends sounds and notions of sound quality and goes right to the heart of the music.
LEYA’s Eyeline features guest spots by claire rousay, Eartheater, Julie Byrne, and more plus a “Dankworld Remix” by Actress on top of violinist and vocalist Adam Markiewicz and harpist Marilu Donovan’s ethereal wanderings. I’ve been listening to LEYA a lot of late for its escapist sonic dream-state and this system, Grimm>totaldac>BorderPatrol>DeVore created a billowing energy-rich cloud of living sound in Barn that offered some of the most convincing reproduction of people making music in my space as I’ve had the pleasure of soaking in in Barn. The S20 has the uncanny, and uncommon in my experience, ability to sound at once completely natural, effortless, and graceful while creating life-like physical forms in space that are richly textured, fully voiced, and beguiling in their immediacy without even a whisper of force. It’s kind of like falling into a cloud that turns out to be the ground. Rich, billowy, yet solid. Uncanny.
Eyeline is rich in sounds layered and woven into a dense fabric and this system gave full voice, scale, and form to every last stitch without sounding overly anything. When reproduction reaches this level of tactile rightness, I find myself physically involved in the musical proceedings as if my body is listening and reacting on its own. This level of reproduction is the kind of thing you just know without having to intellectualize.
Mandy, Indiana is Simon Catling (synthesizer), Valentine Caulfield (vocals), Scott Fair (guitar, mix engineering, production), and Alex Macdougall (drums) and I’ve Seen a Way is their debut, released on Fire Talk last year.
From the liner notes:
i’ve seen a way is a manifesto for these moments of openness and disruption, with sessions in more controlled studio environments spliced with spontaneously captured lo-fi phone recordings, including a field of Swiss cows captured by McDougall while hiking: Fair elaborates that “these locations offered something acoustically, but would traditionally be thought of as having the ‘wrong’ characteristics for producing a ‘good’ recording. These spaces imprint on the sound: It’s not about a lack of access to more traditional recording spaces – it’s about us capturing things happening in a specific place at that moment.”
The S20EXD proved to be a master of reproducing time and place and space, and I ran this wonder of a time and place and space record through the O/96 (A-Side) as well as the review Living Voice R80 OBX (B-Side) with the BorderPatrol in charge and its qualities of supreme naturalness, effortless control, and the ability to project a sound image detached from the speakers and unrestrained by the confines of the space around them felt more akin to a drive-in movie than passive couch sitting.
While the BorderPatrol does not offer the stunning dimensional purity of the Riviera Labs Levante (review), it does create a completely believable sound world to explore as in-depth as you care to dig. And I’ve certainly heard more silky resolving fluidity from the recently reviewed Vinnie Rossi BRAMA (review) and more energized refined precision from the Soulution 330 (review), but the BorderPatrol has its own completely realized sound that is entirely captivating in its own terms.
While I suppose you could call I’ve Seen a Way challenging music, the S20 through the Living Voice and DeVores drew me in to its openness and disruption by recreating its mass of sounds—natural, electronic, and enhanced—with delicate rich reach out and touch it precision. Stunning.
Still House Plants is Finlay Clark on guitar, Jess Hickie-Kallenbach on vocals, and David Kennedy on drums and If I don’t make it, I love u was released back in April on bison. Angular, jarring, and fractured, this record lives and dies by the band’s uncanny sense of time/timing, like a beautifully broken music box or a punch drunk organ grinder with an axe to grind. And the BorderPatrol hung onto every note with dynamics that were more than up to this task, never sounding anything but right on the ever elusive beat. What’s more, Finlay Clark’s guitar rang out as true as I’ve heard with resolution, timbre, and texture describing his chops and hardware choices, as did Kennedy’s machine gun percussion, and Hickie-Kallenbach’s strange and beautiful free jazz classical vocal stylings.
Checking boxes, the BorderPatrol S20EXD does all the things you need an amp to do and adds its own kind of magic, a kind of magic that transforms reproduced sounds into living breathing music presence that cannot be taken lightly. It’s a mind/body kinda ride.
As is my routine, I ran a whole bunch of ‘test tracks’ through the BorderPatrol amp but there was no testing only enjoying happening here. The S20’s voice compliments music, not any particular kind, which is as it should be. Whenever I read how an amp, or speaker or whatever, is good at reproducing a certain kind of music I can’t help but think it must be either broken or just plain bad. A hifi should never act as a filter limiting the music we want to listen to. A hifi should invite us to listen to anything and everything and delight us no matter what. After giving the BorderPatrol S20EXD a very thorough workout of old and new, borrowed and blue music of more genres than yogurt choices in a grocery store, I can tell you with certainty it is voiced to play any music you send its way.
All Life Long is a 1 hour+ suite of pieces for for pipe organ, brass ensemble, and chamber choir by composer and organist Kali Malone, released on Ideologic Organ in February of 2024.
From the liner notes:
All Life Long simmers in an ever-shifting tension between repetition and variation. The pieces for brass, organ, and voice are alternated asymmetrically, providing nearly continuous timbral fluctuation across its 78-minute runtime even as thematic material reiterates. Each composition’s internal framework of fractal pattern permutations has the paradoxical effect of creating anticipated keystone moments of dramatic reverie and lulling the listener into believing in an illusory endlessness. On an even more granular level, the historical meantone tuning systems of each organ used, and the variable intonation of brass and voice, provide further points of emotional excavation within the harmony.
The church organs used date from the 15th to 17th centuries and when we can listen to this music without distraction, whether that distraction is caused by our own lack of focus or the kind of questions poor quality reproduction can raise to interrupt the flow, illusory endlessness doesn’t sound overblown in the least. When a hifi gets things right, all the way down to a church organ’s lowest registers and adds a touch of magic, at least that’s my favorite word for the quality of reproduction I heard from the BorderPatrol, the present evaporates into the kind of temporal timelessness only music can offer. Bravo.
In an ideal world, our hifi should give us everything and more. Everything encompassing the rudimentary check box items that any hifi worth its weight needs to reproduce, while more is where things get interesting, where things get personal. To my way of hearing, the BorderPatrol S20EXD adds more than a touch of delight and beauty to reproduced music that resulted in an uninterrupted flow of magical music moments. Bravo!
1. After I moved the first review unit from the Barn’s B-Side to the A-Side, both channels went silent. No noise, no hum, no sign of anything wrong, just no sound. I went through some basic troubleshooting, checking connections and ensuring the tubes were seated properly alas with no luck. I notified Gary via email and he arrived the following day with a replacement amp. That said, Gary tested the first sample and it measured perfectly and worked fine after re-inserting it into my system so I can only guess that an impossible to repeat combination of an improperly seating tube(s), cables, or gremlins were to blame. I blame gremlins.
BorderPatrol S20EXD Parallel Single-Ended Amplifier
Price: starts at $22,500 without 300B tubes | optional volume control +$500
Recommended Power Tubes:
Western Electric 300B tubes: $3100/matched quad
Genelex PX-300B: $775/matched quad
Emission Labs 300B (solid plate): $1600/two matched pairs
Takatsuki 300B: Market price (typically $1600-2000/pair)
Company Website: BorderPatrol