We are proud to offer the much requested upgrade to the Warm Audio WA-CX24 stereo microphone.  Following in the footsteps of the upgrade we developed for the CX-12, and even subtley improving on that process; this upgrade brings out the fullest potential to the WA-CX24, making an already good value microphone an even much more exceptional value for the money.
 
Power Supply:
we full recap the PSU with both Panasonic long-life electrolytic caps for the filament section and custom made ultra-long life high-temp electrolytic caps for the B+ section.  All capacitors are then bypassed with high quality film capacitors.  The generic IC regulator for filament voltage is replaced with a custom made Sparkos Laboratories 6.2v discrete regulator.  Additional modifications are performed on the PSU's high voltage rail architecture to allow for trim calibration of the B+ and pattern voltages to get the microphone at exact +116v B+ voltage and correct rear diaphragm pattern voltage for both capsules.  The specimen we evaluated was pretty severely underpowered (about 65v B+ and 30v P+ in cardioid... almosst half of what it should be) due to the overly cautious fixed voltage design of the original PSU board.  Bringing the circuit to full power truly brings the microphone to life as it was meant to be.  All components are solder reflowed and all wiring is checked, resoldered, etc.  Board is cleaned.  Using a dremel tool to remove some internal paint and adding the correct M3 screws to the multi-pin connector along with a ring terminal and grounding wire, the connector shell is properly grounded to the interior of the PSU chassis.  
 
Cable:
The cable is inspected and rebuilt on each end, and a grounding wire/modification is done to ground the connector shell to the shield of the cable for complete grounding and to bring the connector up to BBC shielding standards.  A dedicated ground wire is also added to both the PSU chassis and mic chassis, to complete this process and eliminate buzz/hum/handling noise to the extent that's possible.  
 
Microphone:
 
The tube is replaced with a low noise, microphone grade 12AY7 and tube damper rings as well as silicon sheeting on the board beneath the tube to acoustically dampen the tube to the highest degree possible.  A Cu foil shield and drain wire added to both transformers to reduce EMI/RFI.  A dedicated ground wire is added to the chassis to reduce buzz/hum/handling noise.  A Faraday cloth shield layer is added to the inside of the mic chassis to help shield the polystyrene capacitors.  RF suppressor ferrites are added to 3 key areas of the high-z section to reduce RFI/EMI.  the WIMA output capacitors are replaced with selected, tested new oldstock paper-in-oil military surplus capacitors for an enhanced smoothness and 3D quality to the sound.  
 
The microphone is burned in for 24 hours and then given a final PSU calibration before packing up for return shipping.  Return shipping is covered in the USA with the purchase price.