Note that this is a discontinued product. You may want to visit the brand's page here to browse their newer products.
What reviewers think
Bloggers and YouTubers have tried this product—so we've summarized their strongest opinions below. Links to full reviews follow.
Product Strengths
- The BorderPatrol S20EXD consistently delighted with a kind of beauty beyond well-balanced, connecting the reviewer to the music well beyond some sober intellectual exercise—right into the heart of the matter
- The S20EXD delivers power, control, scale, and dynamics without any need to talk about tubes or solid state
- The S20EXD proved to be a master of reproducing time, place, and space
- The S20's voice compliments music, not any particular kind, which is as it should be
- 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
Product Considerations
- BorderPatrol recommends mating the S20EXD with loudspeakers of >90dB efficiency with an impedance characteristic that is relatively uniform and does not drop below 4 Ohms
- Initial tube biasing for the 300Bs requires a DC Voltmeter, a screwdriver, and a few minutes of your time
- One review unit experienced a channel failure that was resolved by reseating the tubes, suggesting potential sensitivity to tube placement
Comparisons (according to reviewers)
- Vs Riviera Labs Levante: The BorderPatrol S20EXD does not offer the stunning dimensional purity of the Riviera Labs Levante
- Vs Vinnie Rossi BRAMA: The BorderPatrol S20EXD offers less silky resolving fluidity than the Vinnie Rossi BRAMA
- Vs soulution 330: The BorderPatrol S20EXD offers less energized refined precision than the soulution 330
Takeaway: The BorderPatrol S20EXD is an amplifier that brings beauty and magic to music reproduction, making it a captivating listening experience regardless of the genre. It offers power, control, and scale, creating a completely believable sound world.
All
S20EXD
reviews

Manufacturer details
- Power Output: 18W per channel
- Configuration: Parallel single-ended
- Output Tubes: 300B (two per channel)
- Recommended Speaker Efficiency: >90dB/watt
- Construction: Chassis made from copper and wood
- Features: Inter-stage transformer coupling, twin external power supply units, hard wiring, cryogenic treatments to amp and PSU
Brand highlights
Taking a step back to look at reviewers' thoughts of the brand's entire lineup—not just this product—what stands out most is the following:
- Border Patrol amplifiers utilize tube rectification and choke input filtering in their power supplies, a design choice they consider critical to their sound and not commonly found in other amplifiers.
- Border Patrol's DACs use vintage R2R DAC chips like the Philips TDA1543, intentionally avoiding oversampling, upsampling, and digital filtering to achieve a more natural sound.
- Border Patrol products emphasize their hybrid tube/solid-state design to blend strengths of both technologies.
Select products
BorderPatrol DAC SE
- Positioning: A mid-range digital-to-analog converter designed for natural sound reproduction.
- Description: Features a copper chassis and a unique combination of solid-state and tube rectification. Uses a discontinued converter chip, which contributes to its distinctive sound signature. This makes it ideal for users seeking a natural and less digital sound.
BorderPatrol S20EXD Amplifier
- Positioning: A high-end parallel single-ended amplifier known for its power and control.
- Description: Uses interstage transformers, which provide significant technical and sonic benefits over capacitor coupling. It offers superior power, control, and dynamics compared to other amplifiers in the lineup. Its dual mono design and external power supplies enhance its performance.
BorderPatrol P20 EXD EXS Amplifier
- Positioning: A flagship push-pull amplifier offering exceptional musical authority and dynamic response.
- Description: Features dual-mono external power supplies and oversized transformers, providing strong voltage regulation and noise rejection. It delivers a solid and planted musical presence, outperforming other models in the lineup in terms of dynamic integrity and speaker control.
Our take on the brand
Look inside the brand
Our interview with the brand
What are two key technological innovations or strong opinions that differ you from other brands?
Not sure about technological innovations, as my products unashamedly use old-school tech (valves and R-2R DAC chips), but strong opinions would be:
- I prefer electronics that have minimal signal processing, i.e., DACs without oversampling and digital reconstruction filters, and amplifiers that do not use negative feedback.
- I believe that power supply quality is very, very important and can often define the product’s sound.
What's your approach to customer support?
Direct contact with me. Fast reply, advice on how to get the best from my products or solve technical issues. Quick turnaround with updates on progress of any repair or service issues. I have been in the audio industry for over 35 years as a dealer, manufacturer, designer, service engineer, and just about everything else. Clients get the benefit of that experience when they buy from me.
What are your favorite tracks for showcasing the strength of your products?
This one is hard, as it changes a lot and I listen to lots of different things:
- Wagon Wheels – Sonny Rollins, Way Out West
- Five Feet Tall – Lady Blackbird, Black Acid Soul
- Symphonic Dances – Rachmaninov, Eiji Oue, Minnesota Orchestra
What other products pair best with yours?
Living Voice Loudspeakers
Used
Border Patrol
What if you spend more?
The Border Patrol P20EXD has carved a solid reputation for fine sound quality, serious musical enjoyment and ability to drive loudspeakers that were thought to be beyond the capability of 20W valve amplifiers. Featuring two 300B output triodes per channel in push-pull configuration giving 20W/channel, the P20EXD handles all music with finesse and aplomb and injects a serious dose of energy and excitement.
The natural timbres of instruments are superbly portrayed with fine resolution and detail retrieval whilst floor-shaking bass can be delivered should the music demand it. The dual external power supply units are once again in evidence providing a super quiet, black background and a solid bass foundation.
Single-ended all the way up to the inter-stage transformer the P20EXD takes advantage of this supposedly antiquated technology to split the phase in a more accurate and time consistent way than the much more common active phase splitters resulting in a purer sound with better resolution and leading edge definition. Described by one hi-fi reviewer as 'one of the finest musical enjoyment devices available' the Border Patrol is sure to illuminate and extract maximum enjoyment from any music collection.
Product Strengths
- The BorderPatrol P20 is able to drive a wide range of speakers with authority
- The P20 offers 'sheer presence, immediacy, and musical impact'
- The P20 gives each instrument and singer its own identifiable voice
- The BorderPatrol P20 offers stability and control, dynamic grip, and a soundstage that stays put
- The P20 is about the fundamental—be that in terms of pitch, structure, or dynamic discrimination
Product Considerations
- The P20 has a low power rating of 20Wpc
- The P20 only has a single pair of RCAs, no balanced-input option
- The P20EXD power supplies are heavy
Comparisons (according to reviewers)
- Vs LAMM ML2.1 monoblocks: The LAMM offers a broader tonal palette with richer instrumental hues and a more obviously transparent and spacious stage, but it can't match the absolute authority of the P20, or its ability to really grip a speaker
- Vs BorderPatrol S20: The P20 is bettered by the LAMMs when it comes to tonal color, and if that's the priority, then the S20 is the amp to consider
- Vs Berning Quadrature Z: Like the Berning Quadrature Z, it is gloriously defiant of sonic categorization, offering its own compelling and penetrating perspective on the musical performance
Takeaway: The BorderPatrol P20 delivers music with pace and intent, and is able to drive a wide range of speakers. It gives music a voice and lets it speak.
Video review
Our take on the brand
Our summary
Product Strengths
- Powerful, able to drive any speaker at any level with ease
- Delivers a new dimension in realism at any volume level, exposing the timbre of bass instruments unlike ever heard before
- Reveals harmonic quality of instruments and voices
Product Considerations
- Heavy, weighing 140lb (63.5kg), requiring assistance for moving and unboxing
- High running temperature (55-65oC across the chassis) and draws 500W from the wall when idle
- When speaker cables are terminated with spade lugs, caution is advised as the posts are close together
- Output is floating—it should not be connected to any loudspeaker with a grounded 'black' terminal
- BAT components take a long time to "break in" (400-500 hours of use)
Takeaway: The BAT REX 500 is a very powerful amplifier that drives speakers with ease and reveals new levels of realism in familiar recordings. It is a must-audition for those seeking reference-level power amplification.
Video review
Our take on the brand
Our summary
Product Strengths
- Delivers 350 watts into 2-ohm, 4-ohm, or 8-ohm loads
- The design has a purity that is quite amazing
- Effortless power
- Soundstage is big
- Transparent
Product Considerations
- Not necessarily suitable for pairing with extremely cold sounding, sterile or bright speakers
Comparisons (according to reviewers)
- MC3500 is more open and airy, with base not as hard fisted, compared to Krell KSA 250
- It compares with brands like soulution, big Audio Research, and CH Precision, but at a lower cost
Takeaway: The MC3500 is an impressive amplifier that delivers a natural and pure sound, able to drive almost any speaker. If you're in the market for a McIntosh amp, this is the one that makes music sound pure, simple and unadulterated.
Video review
Our take on the brand
Our summary
Product Strengths
- Prodigious bass output and rich tonality, especially for a solid-state design
- Great presence, a black background, and strong resolution playing effortlessly at very high volume levels
- Offers a wide, well-defined soundstage
- Beautifully designed with a luxurious appearance, relatively compact dimensions, and attention to detail in its internal layout
- Reserves of power will comfortably drive a wide range of speakers to high levels
Product Considerations
- Attacks can be slightly soft on some material
- The soundstage, while wide and well-defined, may lack the pinpoint accuracy and layered depth of some reference amplifiers
- Requires support beneath it on carpeted floors to allow sufficient airflow
Comparisons (according to reviewers)
- Vs soulution 511, the soulution 511 was faster and more accurately conveyed bass notes, threw an image with greater accuracy, and was more open on top
Takeaway: The Electrocompaniet AW 300 M is a gutsy and poised monoblock amplifier that delivers lots of power and handles a variety of speakers, giving an excellent listening experience. Its solid build and high performance make it a great choice for those seeking high-end audio quality.
Video review
Our take on the brand
What competes at this price?
Our Summary
Product Strengths
- Offers a remarkably smooth, unforced, and natural presentation with a touch of warmth
- Excels in detail retrieval and textured presentation of instruments and vocals, making the music feel alive
- Presents a wide and holographic soundstage, especially when paired with speakers that are already strong in this area
- Demonstrates agility, precision, and clarity, combined with a naturalness that eluded earlier generations of Chord amplifiers
- Scales dynamically and has the ability to punch hard when required
Product Considerations
- Has a minimalist design with just four line-level inputs, lacking features like phono stages, tone controls, headphone outputs, or DAC modules
- Some may find its sonic signature prioritizes articulation over qualities such as richness and authority, potentially sounding thin if partnered poorly
- Balance control has no center indent or marked position
- The polychromatic lighting may be an issue for the color-blind
- Remote operation can be affected by direct sunlight
Comparisons (according to reviewers)
- Vs Rega Elex-R Mk3, the Chord Ultima Integrated delivers undeniably elevated sound in all respects, with greater dimensionality and smoother vocals
- Vs Bryston 7B 3 monoblocks, the Chord Ultima Integrated offers a weightier and more thunderous delivery, especially in the midrange and vocals, with more inner warmth in tone
- Vs Benchmark AHB2, the Chord Ultima Integrated provides a more energetic and fun listening experience, with Thor-like bass impact and overall superior dynamics
- Vs Accuphase E-270, the Chord Ultima Integrated is warmer, rounder, more powerful, and refined, with a more fluid and emotionally engaging performance
Takeaway: The Chord Ultima Integrated is a unique and well-built amplifier that combines a visually pleasing design with a captivating sound, full of detail and dynamic precision. It brings music to life with an engaging and immersive experience, making it a worthy addition to any audiophile's setup.
Video review
Our take on the brand
Our Summary
Product Strengths
- Compact size, lightweight, and runs cool compared to traditional high-end amplifiers
- Exceptionally quiet operation, with reviewers noting a complete absence of hum or buzz
- Delivers a clean, crisp, and neutral sound signature without added coloration
- Upgradeable design, allowing users to update the amplifier with new GaN modules as technology evolves
- Produces a Single Ended Triode-like midrange and top end
Product Considerations
- The polished finish is a fingerprint magnet, requiring the use of gloves for handling
Comparisons (according to reviewers)
- Vs AGD Audion MKIII: The Duets offer a cleaner and more refined sound with improved bass and greater immediacy and snap compared to the Audion MKIII
- Vs Daniel Hertz Maria: The AGD Duets seem to have a little more inner resolution
- Vs Pass Labs X250.8: The AGD Duets performed to a higher level
- Vs Peachtree GaN 1/VTV GaN amps: AGD amps seem to be on another level in regards to design, and the sound is more refined and beautiful
- Vs Aavik U-150, Luxman 595, Yamaha A-S 3200, Axxess Forte 1, Line Magnetic 219ia: The AGD Duets performed to a higher level
Takeaway: The AGD Duet amplifiers offer a blend of cutting-edge technology, exceptional sound quality, and user-friendly design. They are a great option for those seeking a high-end audio experience in a compact and energy-efficient package.
Video review
Our take on the brand
Our Summary
Product Strengths
- Known for combining the musicality of tube amplifiers with the precision and power of solid-state amplifiers.
- It provides a transparent sound with steel control, without the electronic 'shine' associated with transistor amplifiers.
- Exceptional bass performance, described as deep, explosive, and completely controlled.
- Homogeneous frequency range, offering a very high degree of transparency and control.
- Offers an ability to resolve even the finest musically significant details.
Product Considerations
- Requires a substantial amount of space due to its multi-component design.
- The sound offered might be 'too beautiful' for some listeners, as it is not 'brutal' or 'terse' enough.
- Requires care in using its switches to avoid shutdowns.
- Some reviewers note it was 'dark sounding' on the highs, though it did not lack information.
Comparisons (according to reviewers)
- Compared to Quad ESL loudspeakers, it surpasses the musicality and clarity achieved with many tube amps, rivaling even high-end options like Lamm Industries ML2.2 and Miyajima Laboratory 2010.
- The ASR has better bass and is more transparent than MBL, however, it lacks the grace that MBL offers.
- Compared to Rogue 180W monoblocks, the ASR Emitter II delivers better bass.
- The ASR Emitter II has slightly better bass control than Manley Neoclassic 500, but the Neoclassic 500 has a more marvelous style of fiddling.
- Compared to Edge and Audio Research, the ASR is darker sounding.
Takeaway: The ASR Emitter II Exclusive offers a combination of tube-like warmth and solid-state precision, making the listening experience a very involving one. It provides exceptional control and detail across the entire frequency range, making it a great choice for audiophiles.
Video review
Our take on the brand
Our Summary
Product Strengths
- Delivers power while handling subtlety and fine detail with aplomb
- Presents an engaging and naturally organic soundstage
- Offers switchable Ultralinear and Triode tube configurations
- Hand-wired, hand-soldered, and hand-assembled
- The top end is silky, resolved, and decent, resulting in no listening fatigue
Product Considerations
- The bass is not that punchy as with the best high-end amplifiers
- The amplifier can be demanding towards the acoustics of the room due to its heavy-on-bottom balance
- Limited power handling that does not allow for playing too loud
- The 80S sounds more homogenous, although the listening is rewarding and entertaining
- Ensure existing speakers will work with the Reference 80S to satisfaction before purchase
Comparisons (according to reviewers)
- Vs Simaudio Moon 860A v2 power amplifier, the voice of Hana was warmer and velvetier through the Audio Research—a bit more human for my ears—although the sound was slightly less transparent and less controlled
Takeaway: The Audio Research Reference 80S is a tube power amplifier that delivers precision and subtlety. If high-end audio is desired and a lot of power is not necessary, the Reference 80S could be a good fit for a listening space.
Video review
Our take on the brand
Our Summary
Product Strengths
- Uses Moon's new distortion-canceling amplifier circuit, which is incredibly precise.
- Runs as efficiently as possible, yet as close as possible to class A.
- Capable of playing at any volume level, from a whisper to a scream.
- Delivers 200 watts per channel.
- Delivers good stereo, with very powerful dynamic range.
Product Considerations
- Only available in a two-tone 'panda' color scheme (silver sides with a black front panel) at the moment, though this may change with demand.
- Existing Moon aluminum bridges for stacking components are not compatible with this model.
- Moving the 35kg power amp can be a bit of a struggle.
- Although it has a lot of heat sinking, and it does get warm, it's not pulling a huge amount of energy out of the wall at any given volume level.
Comparisons (according to reviewers)
- Vs Hegel H20—the 761 has additional refinement, additional resolution, and is much smoother, but doesn't lose any detail in the music.
Takeaway: The 761 is a very capable amplifier that gives the potential to drive at any level and has the power to play precise, fine-sounding music. It can be used in bridged mode and works in balanced and single-ended configurations.
Video review
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