BorderPatrol Amplifiers

BorderPatrol makes a range of tube power amplifiers that use the ever-popular 300B triode in single-ended, parallel single-ended and push-pull configurations with power outputs ranging from 9 to 20W/channel. All models use inter-stage transformers to couple the driver tube to the 300B's and have no negative feedback to maximise resolution and preserve signal integrity. The audio chassis are composed of non-magnetic materials and the higher priced EXD versions use copper chassis parts and inter-stage and output transformers that have undergone deep cryogenic treatment.

Central to the BorderPatrol designs and philosophy are the large and heavy external power supply units (PSU's). The parallel single-ended S20, push-pull P20 and single-ended S10 are dual mono designs that feature two PSU's, one for each channel. Mounting the PSU's externally not only keeps the weight and size of the amplifiers manageable, it keeps the hard working iron and its electric fields away from the sensitive audio circuitry. It also allows a degree of power supply elaboration and sophistication not found in other tube amplifiers.

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. Other brands use tube rectification and choke smoothing but do so in the cheaper, smaller and easier to implement capacitor input filter configuration. A choke input filter design has far superior voltage regulation (stiffness) and noise rejection. The PSU's stiffness explains why the BorderPatrol amplifiers have bass performance and dynamics unlike any other 300B amplifiers.

In a BorderPatrol amplifier, all aspects of the design have been taken into consideration: audio circuit, power supply, tube complement, materials and component quality. The solutions have been chosen after many hours of listening. The result is the most complete sounding range of tube amplifiers available today and a rare combination of dynamics, integration, resolution and musicality.

Border Patrol S20 parallel single-ended amplifier.

The winner of a prestigious 2004 Hi-Fi+ Product of the Year Award the S20 gives 18 Class A watts per channel from the parallel pair of single-ended 300B output valves and can drive a wide variety of loudspeakers.
The combination of extended bandwidth married to excellent dynamics and a magic midrange make the S20 both capable and musically communicative whilst the twin external power supply units give monoblock-like sound staging and complete channel independence.
Clear, clean, fluid, extended, tonally rich and natural are all adjectives used to describe the performance of this fine amplifier.
Marrying finesse and sophistication to dynamics not usually found in SET amplifiers, the BorderPatrol S20
is a fine musical transportation device.
Recommended loudspeaker efficiency <89dB/watt for best performance.

The BorderPatrol S20 can be ordered with the EXD pack where copper chassis parts, cryo-treated transformers and upgraded components serve to further increase the resolution and improve the tonality of the amplifiers. It is also now also available with the EXS power supply units.

OK, so this isn't really a new product introduction, but I was so blown away by the BorderPatrol S20's performance with Volti Audio's Vittora speaker system that I just had to include it here.
Dick Olsher The Absolute Sound.

'Another atypical aspect of this amp is its response. Valves are famous for having a glorious mid-band and a tendency to emphasise this above all else. The S20 while phenomenally transparent in the mid-band has a remarkably flat response. You don’t miss out of the frequency extremes with it: This is a wide band amplifier!'

'The mid-band is proper SET stuff though, voices are superb and you can hear all the words all of the time. This is a fluid and revealing amp that combines a delicacy that lets you hear micro dynamics clearly with an ability to swing real energy when it’s required.'
Jason Kennedy HI-Fi Choice Collectors Edition Summer 2004

'At first glance it looks to be of a similar build quality to many other small brand amplifiers; in other words fine but nothing to write home about. But look a little closer and use the product for a while and you realise that this is a fully finished well thought out component that will stand the test of time as well if not better than machine made audio electronics. Look under the lid at the way components are connected up and held in place and it inspires a confidence that can sometimes be lacking in the valve world. Standard of finish is high throughout, but stops just short of slick while the paintwork is perfect and the screen printing professional. This is a solid product make no mistake.'
Jason Kennedy Hi-Fi+ issue 35.

BorderPatrol S20EXD from $17,750

BorderPatrol S10 and SE300B single-ended amplifier.

The BorderPatrol S10 and SE300B continue to redefine the capabilities of 300B single-ended amplifiers. Using a single 300B output triode for each channel, the amplifiers surprise critics not just with their resolution but with dynamics and control which are thought to be beyond single-ended designs. The poor bass and weak dynamics that are associated with designs of this type are removed by the sophisticated external power supplies and the amplifiers are models of sweetness, clarity and vibrancy with fine, extended bass and dynamics.

The S10 features a single ended output stage which is the simplest and purest circuit topology available. It is dual mono and each channel has its own an external power supply unit.

The S10 can be ordered with EXD specification where copper chassis parts, cryo-treated transformers and upgraded components serve to further increase the resolution and improve the tonality of the amplifiers. They are also now available with the EXS power supply units.

The SE300B is the stereo version of the S10 and uses a single PSU to power both channels.

'What the Border Patrol EXD/EXS combination does superbly well is to establish what may be an industry benchmark in reproducing the correct and fully developed tonal envelope for every instrument and voice played through it. It just gives music a sense of rightness in this critical aspect of realism that places it firmly in the playing field with the finest 300B SET amps of the day.'
Steve Marsh 6-Moons

2013 saw me successfully exorcise an SET obsession with the happy acquisition of the BorderPatrol S10 EXD stereo amplifier. Delightfully retro in looks and stunningly modern in its full-bandwidth linearity and deep, muscular bass response, this 300B amplifier has completely redefined what a tube amp can do and what an SET amp should be. Quite simply, I’ve never heard anything like it. Matched with the (Volti) Vittoras or the (DeVore) O/96, I found my audio happy place and I’ve been rolling around in that sound like a pig in a poke ever since.
Scot Hull
Confessions of a Part-Time Audiophile Best of 2013.

'There are no rose tinted specs, slurred and rolled off frequency extremes or over stuffed harmonics here.  In fact, for the first time in my experience, I'm listening to an amplifier with the linearity and directness that are supposed to be single-ended's great virtues.'
Roy Gregory Hi-Fi+ issue 8

'...the Border Patrol might have dipped out on the syrupy sweetness part of the single-ended deal, but it delivers the “real sense of power” with consummate ease, another area in which most of its compatriots fail to live up to their billing.  Instead of lush and overblown, the 300B SE (WE) is wonderfully (and correctly) rich.  Instruments have a natural weight and colour, and voices, especially tenors, have tremendous authority and a real sense of substance.
Roy Gregory Hi-Fi+ issue 8

'Passion, grace and fire.'  
Jason Kennedy Hi-Fi Choice Jan 99 

'Uncommonly capable single-ended design with less colouration and more grunt than any of the alternatives- resolution guaranteed.'  
Jason Kennedy Hi-Fi Choice Jan 99 EDITORS CHOICE

BorderPatrol S10 from $18,500

BorderPatrol SE300BEXD from $13375

Border Patrol P20 push-pull amplifier.

The Border Patrol P20 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, this time in a push-pull configuration giving 20W/channel, the P20 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 P20 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.

The P21 is the stereo version of the P20 and uses a single PSU to power both channels.

Recommended loudspeaker efficiency >87dB/watt 

Both P20 and P21 amplifiers can be ordered with EXD specification where copper chassis parts, cryo-treated transformers and upgraded components serve to further increase the resolution and improve the tonality of the amplifiers. The P20 is also now available with the EXS power supply units.

The P20 — a push-pull design — changed things up, as you’d expect. What it did was pure tube, but with great linearity and extraordinary bass. I think most “tube lovers” would cotton to this sound pretty much immediately as it has all the tube hallmarks. Great tone, great mids, but in a linear and resolved package.
Scot Hull Part Time

'Superb amplifier with bags of power and genuine resolution, one of the best music appreciation devices available.'

'In the right company this amp delivers transparency, fluidity of timing and grunt like few others out there...... if it's the musical essence you're after it's a tough act to follow.' 
 Jason Kennedy Hi-Fi Choice Summer 2002

'Here, the authority shape, pacing and tactile presence that the P20 brought to the nether regions of these physically modest speakers (Reference 3A and Living Voice Avatar OBx-R) imbued them with a scale and sheer unflappable stability totally at odds with expectations. Tonal colour and separation were superb, with none of the qualitative sameness that collapses the individual character and texture of instruments (and performers).'

'The P20 is a mightily impressive amplifier and one that explodes the triode myth. Once again, it proves that it's not what you use but how you use it that counts. Good engineering will win out. I've listened long and hard to the push-pull Border Patrol and still haven't got its full measure.'
Roy Gregory Hi-Fi+
Issue No 25 August/September 2003.

BorderPatrol P20 from $17.750

BorderPatrol P21EXD from $13150

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