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Description of Item:
This is the premier and only Phase Linear PL14 or PL20 Universal Control Board Upgrade kit available on the web. It is a professional-class upgrade product, meticulously engineered to look and perform better than the original.  Professional grade, "UNIVERSAL" PL14A/B + PL20 main audio board Upgrade Assembly to enhance the quality of the components, circuit design and PCB on existing Phase Linear 400 and 700B amplifiers - direct drop in kit for PL14 A & B and PL20 equipped amps (the vast majority of all Phase Linear amplifiers).  Design flexibility allows you to build it out as "stock" or "enhanced" by populating the component options you desire.  Swap out the original single-sided PCB with a premium double-sided, silk screened and solder masked circuit board.  Upgrade to high quality, low noise, metal film, precision resistors and improved audio grade Wima polypropylene and Cornell Dubilier (CDE) Mica (audio path) and Nichicon MUSE electrolytic capacitors  (power supply segments only) throughout.  Improve the signal integrity of your amplifier.

Do you own a Phase Linear 400 Series 1 or 700B Amplifier (the ones with the 2 big VU meters)? They are great amplifiers but the original control board is aging and possibly not providing you the best possible sound performance anymore or has become intermittent and unreliable. Here is your opportunity to replace the original control board with a high quality, premium component equipped replacement and bring your favorite Phase Linear amp back to its original glory.   The complete kit and assembled boards use Wima Polypropylene and Cornell Dubilier Mica non-polar capacitors and Nichicon MUSE audio grade electrolytic polar capacitors to replace the original ceramic and aluminum electrolytic types and precision, low noise metal film resistors throughout to replace the original carbon film types.

This is a brand new, upgrade blank PCB kit to replace the original control board (PL14A or B or PL20) with a premium grade replacement. This kit includes the bare board and all electronic components except the 2N1304 and 2N1305 germanium transistors, which can be harvested from your existing board or purchased separately from multiple web sites.  These transistors are no longer produced and are excluded from the kit to keep the kit price reasonable.  A link to the assembly instructions and documentation is also provided. The components in the kit will be pre-formed for you.  The components you receive in the kit may differ slightly in appearance from those pictured due to parts manufacturer changes.

You will get what you see installed on the PCB in the picture above:
  •  Brand new upgrade blank PCB to replace the original PL14 or PL20 PCB
  • All 1/4 and 1/2W 1% metal film resistors
  • All 2W 5% metal film resistors
  • All potentiometers as Cermet type
  • All non-polar capacitors as Wima Polypropylene (higher value NP caps) or as Cornell Dubilier Mica (lower value NP caps)
  • All polar capacitors as Nichicon MUSE audio grade electrolytics
  • All Diodes
  • All Transistors except the 2N1304 and 2N1305 germanium transistors (harvest from your existing board or purchase new on web)
  • All voltage regulator ICs
  • All Aavid transistor heatsinks and transistor insulators
  • All hardware
  • Solid Copper Bus wire and Teflon tubing to allow tying power and ground for both channels together
Detailed photographs, assembly parts list and "crystal clear" assembly and installation instructions are located at this link below:



The printed circuit board is a high quality FR-4 based, epoxy-glass PCB with HASL tin/lead plating on the solder pad areas replacing the original single-sided PL-14 or PL-20 PCB. The replacement PCB is 0.062 inch thick double sided circuit board with plated through holes and white epoxy silkscreen legends on the component side and green solder mask on both sides. It is a direct drop in for the original board size, using the original mounting hardware to secure it in the amplifier. This replacement board includes holes to securely attach the amplifier wire connections to the PL14_20 Control board rather than the original backside only solder connection used by Phase Linear. This feature can be seen pictured in the photo. The original wire attachment points would often separate from the PCB, ruining the board.

This upgrade kit is for skilled technicians. Building and installation of this kit is more advanced than the other White Oak Audio Design kits.  The installer should be familiar and comfortable with working on electronic equipment and using a soldering station and associated tools. Ensure good control of soldering iron temperature, not exceeding 600 degrees F, so the PC Board and components are not ruined by excessive heat. If you are not familiar with working on electronic equipment or do not possess the proper equipment, it is recommended that you take your amplifier to a service technician that can perform the LED Light Board Upgrade and installation for you. Bare board only kits as well as assembled and tested versions of this LED light board are available as well on the White Oak eStore.

Photos of the finished project are shown below (installed in chassis with original PL14 PCBA component side showing for comparison, installed in chassis with original PL14 PCBA solder side showing for comparison).
This kit is sold AS-NEW with no returns (due to potential damage to the circuit board once assembly has begun).

Ship From Zip Code: 01564
Shipping Weight:16 oz. for Complete Kit or Assembly, 4 ounces for Bare Board.
White Oak Audio will pay USPS Small Flat Rate Box Priority Mail shipping charges (but not insurance) within the continental 48 US states for Complete Kits and Complete Assemblies. If you require other than this mail service, buyer will be responsible for shipping charges by method selected on the shipping weight stated above. If you do not pay for shipping insurance, delivery will be made totally at buyer's risk for loss and damage.  Bare boards will be shipped in a bubble padded mailing envelope via USPS First Class Mail.

Your purchase will be professionally and neatly packaged for shipment within the standard USPS Small Flat Rate Box. International orders are also welcome, shipping charges are not included in the cost but generally are $8.25 extra to most international destinations (contact us for a shipping quote to your destination).

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