Upgrades There is an on-going development program at BP in which new circuitry, materials, components, valves and treatments are evaluated. The aim is to find ways to make the amplifiers sound more natural, revealing, dynamic and more musically satisfying.
Dynamics is an overused term in audio and to most it simply means the ability to play loud and hit hard but equally if not more important is the other end of the dynamic spectrum. At the micro-dynamic end of the spectrum the systems ability to resolve and portray the smallest pieces of information provides the vital clues about instrument timbre, vocal inflections, interplay between musicians and room acoustics that can turn a recording into a living musical event. Improvements in the micro-dynamic capabilities are made by lowering the noise floor and should not be made by engineering a treble lift to give superficial air and space. It is fundamentally important that the overall substance of the music is not lost in the quest for increased information. Many systems dissect recordings in the quest for increased information retrieval and destroy the music in the process. Having all the information may be great but if it's unpleasant listen to you have a problem and after all, whilst hi-fi may satisfy the mind, it's music that stirs the soul. I will be visiting the UK two or three times a year to upgrade amplifiers. For more details and prices, please
e-mail
bp@borderpatrol.net
|  | Amplifier upgrades.
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Upgrade | Work required | Sonic | Models | | | | | EXD PACK | Complete strip down and re-build of the amplifier into copper chassis parts.
Changing the inter-stage and output transformers to cryogenically treated ones.
Re-building audio the circuit with our preferred carbon film resistors.
Any tweaks and detail changes required to bring up to the latest spec. | The amps become clearer and easier listen to with much finer dexterity and flow coupled to a much more relaxed and natural tonality. The noise floor is much lower improving resolution and clarity The copper chassis parts impart a richer, more lustrous tonality with a cleaner background and less hash and grain. The carbon film resistors are more natural and uniform sounding that the metal film/wire-wounds used previously making for a more relaxed, less edgy sound and the cryogenically treated transformers have superior resolution and micro-dynamic capability coupled to a lower noise floor. The overall effect is a much more natural and relaxed sound with much better clarity, resolution and fluidity. | SE300B, S10, P20, P21, S20 | | | | | | High sensitivity configuration to low sensitivity configuration. | Changing the CV4068/E182CC input/driver circuit to the current specification low sensitivity 6C45pi configuration. * -see below. | The 6C45pi input stage sounds cleaner and 'simpler' than the CV4068/E182CC and the lower input sensitivity allows active pre-amplifiers to be used without noise and gain issues which results in a much more alive and dynamic sound. | SE300B, S10, P20, P21, S20 | | | | | | Convert to Dual Mono Spec | The addition of a 2nd PSU and 2nd set of power supply capacitors and re-configuring the circuit to dual mono. | Adding the 2nd PSU greatly improves the dynamic capabilities of the amplifier in the same way as moving from a stereo amp to mono-blocks. When both amps feed from a common power supply dynamic events on one channel will affect the other channel even if the PSU is very stiff. This compromises stereo separation and image placement and can result in a perceived lack of headroom and security. With a separate PSU for each channel each channel can do its work unaffected by the other one and the result is a more relaxed and secured sound with greater headroom and control. | SE300B, P21 | | | | | | Re-wire audio circuit with Kondo Silver cable or other cable. | Re-wire audio circuit with Kondo Silver cable or cable of you choice. | If you have preferred interconnect or cable that is used throughout the rest of the system, re-wiring the audio circuitry with this interconnect will have a profound and beneficial effect. | SE300B, S10, P20, P21, S20 | | | | | | Western Electric 300B | | In my opinion the best 300B available. The rest are either 2nd rate imitations or not 300B's. The Western Electrics have a musicality and uniformity that cannot be defined in hi-fi terms but is instantly appreciated when experienced and they have unmatched resolution. | |
* BorderPatrol amplifiers have been made in three formats: Low sensitivity, high sensitivity and high sensitivity with volume control added.
The low sensitivity 6C45pi format is designed for use with active pre-amplifiers. It needs plenty of drive and the low sensitivity enables it to be used with a wide variety of active pre-amps without gain and noise issues. Using the low sensitivity configuration with an active pre-amplifier such as the BorderPatrol Control Unit is by far the best option.
Some users have used this format directly connected to a high output CD player with inbuilt variable volume control and while this worked as a 'get off the ground' solution they all subsequently added the BorderPatrol Control Unit. The high sensitivity amp format can be used with active pre-amps but there are often gain and noise issues, particularly when coupling with very efficient loudspeakers. Using this format with a passive pre-amp solves the gain and noise issues but in my opinion is by far the worst solution and invariably results in a slow and uninvolving lifeless sound with poor frequency extension and dynamics. The high sensitivity format fitted with a volume control has capabilities that lie between those of the active pre-amp and the passive pre-amp. It is significantly more dynamic and alive than the external passive pot solution but not as good as when using an active pre-amp. Control Unit pre-amplifier upgrades. Since the introduction of the Control Unit pre-amplifier there have been numerous detail revisions and changes that have made a much smoother, more natural and cleaner sounding pre-amp. Upgrade | Work required | Sonic | Models | | | | | Service
Pack 1 | Brings old Control Units up to the latest specification. Involves fitting different resistors and capacitors, superior volume pot, superior selector switch and numerous small tweaks and refinements. | There was a suggestion that the original Control Unit could sound etched and less than relaxed in some systems. Whilst this made for a revealing listen it could be fatiguing. The latest specification is considerably more relaxed and refined whilst being equally dynamic and revealing. | All Control Units prior to 2006 | | | | | | EXD | Adding a 2nd power transformer to PSU to create low distortion PSU topology.
Fitting custom made polypropylene PSU capacitors.
Superior selector switch and volume control.
Numerous detail teaks and refinements
Bringing Control Units up to latest spec. | Removes noise and grain therefore improving the resolution and lowering the noise floor.
Widens and deepens the sound stage.
Makes the pre-amp sound much more fluid and free, and more natural and less Hi-Fi | All Control Units | | | | | | Re-wire | Re-wiring of audio circuit.
Boutique input/output sockets - ask for details. | If you have preferred interconnect or cable that is used throughout the rest of the system, re-wiring the audio circuitry with this interconnect will have a profound and beneficial effect. | |
Power Supply upgrades Upgrade | Work required | Sonic | | | | Conversion to MB specification | Change power transformer and choke of the BorderPatrol PSU to the high performance MB specification units. | Lowers the noise floor and improves micro-dynamic resolution.
Improves the dynamics. Bass is even better defined with additional control. Greater sense of solidity and headroom. Takes the improvement brought by the standard supply to another level. |
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