WA-CX24 full upgrade
We are proud to add the CX-24 full upgrade to our roster. This modification is a thoroughly comprehensive rebuild of the WA-CX24, rebuilt to be more reliable last forever, and sound amazing.
The power supply is fully rebuilt from end to end with all new capacitors of the highest grade, including high quality film and multilayer ceramic cap bypassing of all capacitor locations. Every solder joint is re-flowed and every wire is re-installed and tidied up. The regulator voltage is corrected and the regulator re-installed with thermal paste added to the heatsink and bypassing of the 'corrective' diode in the regulator circuit (replacing the 6.7v heater over-voltage with a more stable 6.1v, slight under-heating for longer tube life. The B+ voltage rail is modified to include a trimmer potentiometer for precisely dialing in the B+ voltage of +120v and capsule voltages of 0-120v, opposed to the much lower 'starved' voltages often measured on these units. The heater voltage, capsule voltage, B+ voltage, and bias voltage are all checked and recalibrated again after burn-in time. A dedicated chassis ground wire is added to the panel-mount multi-pin connector housing to ground the shell of the multi-pin connector and shell housing.
The tube is replaced with a 12AY7 that is third-party graded for low noise/low microphonics, with the tube pins lubricated and 2 silicon damper rings added, as well as resting the tube on a silicon adhesive pad between the tube and board. RF suppressor diodes are added to both tube grid inputs, and the polystyrene capacitors are partially shielded with a kapton tape/copper tape-tied-to-ground/kapton tape barrier. The windings of both output transformers are shielded with a copper foil tape layer, also tied to ground, between two layers of additional kapton tape. A dedicated chassis ground wire is added to the frame to ensure grounding of the microphone body and multi-pin connector housing and shell. The output capacitors are replaced with high performance custom made JB audiophile film capacitors, which are wrapped in kapton tape and held in place with adhesive. additional adhesive is added to the polystyrene capacitors. The two channels of microphone output wire pairs are shorted and twisted at a high ratio for better CMMR and isolated from the other wires.
The microphone is then burned in for at least 12 hours, re-checked, re-calibrated, and packed back up for return shipping.
NOS PIO (paper in oil, from the cold war era) capacitors available on request as an alternate to JB film capacitors, for a slightly more warm/forgiving sound.
