Electronics
Border Patrol
Border Patrol manufacturers the finest sounding vacuum tube electronics we have encountered. Their designs feature elegant, minimalist circuit paths constructed from the finest components. All Border Patrol products are hand-wired point to point, and are built to order. There is a certain pride of ownership that comes along with a product manufactured in such small volumes, with such care and thoughtfulness.
Border Patrol components are perhaps best know for their total lack of coloration or distortion. Sure, they satisfy all the audiophile criteria with aplomb - they soundstage marvelously, imaging is pristine, the midrange is liquid, bass is full, rich and extended, and high frequencies go on forever without ever sounding harsh or etched. But it's more than that. There is something that just sound inexplicably "right" about a Border Patrol amplifier driven by their preamplifier. Audiophiles search for buzzwords, but frequently we find that the best explanation is offered by those less familiar with the industry jargon. Customers often remark that when they hear Border Patrol electronics played through Wilson Benesch loudspeakers for the first time, it is as if a group of musicians sat down and started play right in front of them. There is no sense that one is litening to reproduced music through a "stack" of components, and a pair of loudspeakers. That level of transparency and musicality can only be obtained with Border Patrol's superlative components.
Pre-Amplifier
The Control Unit is equally at home playing classical, rock, jazz, ethnic, technology or any other music genre and we are sure that it's musical capabilities will more than exceed your expectations.
The Control Unit uses a single 5687 triode valve for each channel configured as an anode follower. This valve is chosen for it's low gain, low output impedance, low microphony and low noise. Hovland Musicap capacitors are used for signal coupling. No negative feedback is employed and the circuit is hard wired into un-printed boards. A double section choke input filter, EZ80 valve rectified H.T. supply with Black Gate capacitors provides the high voltages for the circuit and unusually, and perhaps uniquely, a similar choke input filter supply is used for the filament supply, though this time Hexfred diodes are used as rectifiers. Input and output sockets are mounted on a copper ground plane. The chassis is made from 2mm copper plate. A phono version is available featuring a 2 stage hard wired triode phono stage that uses a ECC83 and 6922 double triode.
Inputs: 5 x line level inputs marked as Phono, CD, Tuner, Line and Tape but any line-level component such as a DVD player or VCR can be used.
Gain: 12dB
Power Amplifiers
It is often commented, correctly, that though most valve amplifiers have
wonderfully communicative midrange and sound tonally rich and warm, they
have poor bass performance and dynamics and are incapable of capturing the
drama and tension in music. Our intensive research into power supply design
has overcome these dynamic problems. With a Border Patrol amplifier you can enjoy the sweetness, clarity and tonal realism that valve amplifiers are renowned for without the usual weaknesses of poor bass and dynamics. All the drama and tension is effortlessly portrayed.
All Border Patrol amplifiers feature triode valves, the simplest and
most accurate amplification devices of them all. The triode circuits are
employed without negative feedback, an engineer’s tool that may give wider
frequency response and reduce harmonic distortion on the test bench but
ruins the sonic’s by obscuring low level details and smearing the timbres of
instruments and the leading edges of the sounds. Border Patrol
amplifiers also share other common features.
Each circuit is designed to be
as simple as
possible to maintain signal integrity and each component is critically
evaluated to make sure it blends into the whole. All the amplifiers are point
to point hard wired and constructed from non-magnetic materials to minimize
the deleterious effects of electric fields on the audio signal. Inter-stage transformer
are used to couple the small
signal valves to the large output triodes. Something of a lost technology,
inter-stage transformers were abandoned decades ago by amplifier
manufacturers for reasons of cost and size despite their technical and sonic
benefits.
And, all Border Patrol amplifiers feature heavy duty external power supply
units, either one for the SE300B and P21 stereo amplifiers, or two, one for
each channel, for the P20 and S20 dual mono designs. Each power supply unit
contains three independent valve rectified choke input filter high voltage
power supplies that feed different parts of the amplifier circuit with clean
filtered voltage. These heavy-duty external power supply units are central
to Border Patrol philosophy and performance. The power supply units use
valve rectifiers,
and chokes, again, something of a lost technology, and they are mounted
externally to keep the electric fields of the power transformers and chokes
well away from the sensitive audio circuitry.
More than anything the power supplies are responsible for the combination of
dynamics, bass performance, clarity and resolution that set Border Patrol
triode amplifiers apart from other valve amplifier brands.
The 1st
Border Patrol amplifier, the SE300B was introduced in 1995 and quickly redefined
expectations about what a 9watt/channel amplifier was capable of. Using a single
300B output triode for each channel, the amplifier surprised critics, not just
with its resolution but with dynamics and control which were thought to be
beyond the capabilities of low powered single-ended amplifiers. The poor bass and weak dynamics that had been associated with designs
of this type were removed by the sophisticated external
power supply unit and the amplifier is a model of sweetness, clarity and
vibrancy with fine, extended bass and dynamics.
The SE300B features a single
ended output stage, which is the simplest and purest circuit topology
available, and fully maintains the integrity of the signal. Here the signal
travels through the amplifier in one piece unlike a push-pull circuit where
it is split into two equal but out of phase halves before being ‘put back
together’ at the end. A single external power supply unit feeds both
channels and each power supply unit contains three independent valve
rectified high voltage supplies that feed different parts of the amplifier
together with additional supplies for the valve heaters. The inside is
something of a an audiophiles component gallery. Different brands of 300B
output valves are also offered which subtly tailor the sound of the
amplifier. Clarity, resolution and tonality are outstanding and the
amplifier excels on all types of music.
The
SE300B is often seen at hi-fi shows driving large horn-loaded loudspeaker
systems but the amplifier is equally comfortable driving more real world
designs, though the recommended efficiency for partnering loudspeakers to
extract the maximum performance needs to be greater than 90dB/watt. One
reviewer was staggered to find the SE300B driving a loudspeaker that had
defeated everything but his 400W channel transistor amplifier.
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.'
'Uncommonly capable single-ended design with less colouration and more grunt than any of the alternatives- resolution guaranteed.' Jason Kennedy
' ....., I went back to my transistors.....there was a congested quality, as though the system had picked up sinusitis.' Paul Messenger
BorderPatrol
S10.
Audiophiles are rarely satisfied and BorderPatrol
SE300B owners began to demand upgrades to their amplifiers. Following the
success of the dual mono S20 and P20 models the S10 was conceived. Take the BorderPatrol SE300B, fit an extra
power supply and reconfigure the circuit to dual mono (right back to the
needing two mains leads) and you have the BorderPatrol S10. Stereo
separation, dynamics, stability and control are all improved compared to the
SE300B. Any owner of a high efficiency loudspeaker system should strongly
consider this amplifier.
The Border Patrol
S20.
'Another atypical
aspect of this amp is its response. Valves are famous for having a
glorious midband 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
midband 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
'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
The subject of two recent reviews in the hi-fi press, both of them
unequivocally complimentary, 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 effortlessly portrayed
with fine resolution and detail retrieval whilst floor-shaking bass can be
delivered should the music demand it. Once again, the external power supply
units are 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 much 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.
'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
'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
BorderPatrol P21
The
BorderPatrol P21 is a BorderPatrol P20 reconfigured to stereo with one power
supply unit. It has all the trademark Border Patrol sound
qualities; clarity, dynamics, bass and tone in abundance and with capability almost matching the P20 but at a lower price, this amplifier offers excellent value. The P21 can be upgraded to dual mono P20 specification.
The Control Unit pre-amplifier is the result of a long and protracted design process during which many circuit topologies and components were rigorously evaluated and selected on a purely musical basis. Many manufacturers simply prescribe a collection of 'audiophile' components and assume that incorporating them into their product will automatically ensure good sound. This is usually far from the case. Each component has to be evaluated, regardless of reputation, and selected only if it blends into the whole. The operating conditions of the valves need to be carefully tuned in, and the qualities of each part of the circuit need to be harmonically in sympathy with each other. The aim, like in all BorderPatrol products, is not to produce an amplifier that excels in one particular audiophile area but one which has balanced and integrated musical qualities.
Specifications
Outputs: 2 x outputs to facilitate bi-amping or connection to an active subwoofer. 1 x tape out. This output can also be connected to 5 channel processor.
Output Impedance: 2kOhm
Frequency response: -3dB 7Hz-200kHz.
Input voltages: 0-220-230-240V or 0-110-115-120V
Recommended Interconnect length: < 3m. Low capacitance interconnects are recommended.
Dimensions: 450mm x 350mm 120mm
Weight: 12kg
Valve Complement: Line 1 x 5687, 1 x EZ80; Phono 1 x ECC83, 1 x 6922
Power Consumption: 24 Watts
Border
Patrol valve amplifiers combine superb sound quality with
clean retro visuals. The elegant hardwood plinths house modern, state of the
art triode valve circuitry that use the latest high performance modern
components. Valves are used, not because of nostalgia, but because they are
still the most linear amplification devices and so have tonal and resolution
capabilities that continue to elude the solid-state alternatives.
Border Patrol SE300B
'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.'
Hi-Fi Choice Jan 99
EDITORS CHOICE
Hi-Fi Choice Jan 98
Originally conceived as a double power SE300B, the S20 has shown it has
far more to offer than just that and is now the most popular Border Patrol
power amplifier.
The winner of a 2004 Hi-Fi+ Product of the Year Award the
S20 gives 20 Class A watts per channel from the parallel single-ended 300B
output valves and can drive a wide variety of loudspeakers. The
combination of clean extended sound married to
excellent dynamics and a
magic midrange make the S20 both capable and communicative. With the
improved sound staging, headroom and tonal body that come from having double
the power and a separate power supply for each channel the S20 is a fine
musical transportation device. Clear, clean, fluid, extended, tonally
rich and natural are all adjectives are used to describe the performance
of this fine amplifier.
HI-Fi Choice
Collectors Edition Summer 2004
Hi-Fi+ issue 35.
The Border Patrol P20.
Hi-Fi Choice Summer 2002
EDITORS CHOICE
Hi-Fi+ Issue No 25
August/September 2003.
