Step 6 — Wire the Q Filter

Resonant boost — replaces the tone pot
CTS 50K rev-log as a rheostat · mode cap to ground
No Greasebucket, no tone control
BLEND Bourns 250K MN dual-gang VOLUME CTS 500K log push-pull DPDT 2 WPR Q CTS 50K rev-log · rheostat 1 COLD 2 WPR 3 IN GROUND BUS SIGNAL NODE tip · buffer · Q DPDT SWITCH (on volume pot shaft) POLE 1 POLE 2 1 PAR GND 2 NCK GND 3 SER BRG 4 6.8nF 5 Q WPR 6 22nF 6.8nF parallel 22nF series Vol wiper → node → tip (passive) & buffer IN 6.1: Q1 ↔ Q2 jumper (rheostat) 6.2: SIGNAL node → Q Lug 3 6.3: Q wiper → SW5 (Pole 2 common) SW4 → 6.8nF SW6 → 22nF 6.8nF → GND 22nF → GND ⚠ NO TONE POT, NO GREASEBUCKET The Q is a resonant BOOST to ground, not a treble bleed. No 22nF+4.7k+100nF stack, no 250K no-load pot anywhere. Q-FILTER (replaces the tone control) 50K rev-log as a 2-terminal rheostat → mode cap → ground. Parallel + 6.8nF: +6.9 dB @ 1165 Hz (centred) growl peak. Series + 22nF: dark, treble rolloff, no boost. A dial, not a switch: flat at 50K, full boost toward 2K. ⚡ CONTINUITY CHECK Q full (50K) = flat. Wiper→SW5→cap→GND must read the cap, not 0Ω. SIGNAL NODE → Q Lug 3 → track → wiper (Lug 2) → SW5 → mode cap (6.8nF / 22nF) → GROUND
Signal node feed (→ Q Lug 3)
Q-filter cap wiring
Rheostat jumper (Q1↔Q2)
Ground connections
Ground bus
DPDT coil pole (faded)

Step 6 Instructions

6.1 — Q Lug 1 (COLD) → Q Lug 2 (WIPER) jumper. Solder a short link between Lug 1 and Lug 2. This turns the CTS 50K reverse-log pot into a two-terminal rheostat (a variable series resistor). Reverse-log taper spreads the useful boost across the sweep.
6.2 — Signal node → Q Lug 3 (IN). Tap the signal node (the Volume wiper) and run it to Q Lug 3. The Q filter hangs off the node in parallel with the jack tip and the buffer — it does not sit in series with the main signal path.
6.3 — Q wiper (Lug 2) → DPDT SW5 (Pole 2 common). From SW5 the signal reaches ground through whichever mode cap the push-pull selects: 6.8nF (parallel / down) via SW4, or 22nF (series / up) via SW6. The pot resistance plus that cap form the resonant filter. No direct short to ground.
Result: one knob walks the bass from the J's scooped voice (flat) into P-bass bark (boost) — a passive resonant boost in place of a tone pot.