Step 4 — Wire the Volume Pot

WIRING SIDE (back of control plate)
CTS 500K log · push-pull DPDT · wiper = SIGNAL NODE
Hover any wire group to isolate
GROUND BUS BLEND 250K MN dual-gang BLEND OUT from step 3 Q 50K rev-log rheostat 3 IN RING-HOT BUFFER 2N5457 → 2N3904 · phantom powered IN GND RING OUTPUT Switchcraft 12B TRS TIP passive RING SLV VOLUME CTS 500K log · push-pull DPDT 1 GND 2 WPR 3 IN SIGNAL NODE fans to Q · buffer · jack tip 4.1 V1→GND bus 4.2 BLEND OUT → V3 (step 3) 4.3  V2 wiper → SIGNAL node 4.4 SIG → Q IN 4.5 SIG → buffer IN 4.6 SIG → Jack TIP (passive, always) VOLUME — CONNECTIONS 4.1 V1 → ground bus 4.2 BLEND OUT → V3 (step 3) 4.3 V2 wiper = SIGNAL NODE 4.4 node → Q IN 4.5 node → buffer IN   4.6 → tip THE SIGNAL NODE (no tone pot) The volume wiper IS the one signal node. It fans to three: • Jack TIP — passive direct, always (plain TS cable = stock bass) • Buffer IN — phantom-powered, feeds the ring • Q-filter IN — the resonant boost that replaces tone All three sit on one node — the loads run in parallel off the wiper.
Ground (to bus)
Signal path / node fan-out
Context from step 3
Buffered ring (phantom)
Ground bus (faded context)
4.1 Volume Lug 1 → solder a short wire to the ground bus (pot casing / bus wire)
4.2 Blend out → Volume Lug 3 — already done in step 3 (shown faded as context)
4.3 Volume Lug 2 (wiper) = the SIGNAL NODE. From here, fan out to three loads:
    4.4 node → Q-filter input (Q Lug 3)
    4.5 node → buffer IN pad
    4.6 node → jack TIP (passive direct, always)
SIGNAL NODE — fans to Q, buffer, jack tip. There is no tone pot in this harness. The volume wiper is the single signal node: the jack TIP gets it straight (a plain TS cable plays the bass as a stock passive instrument), the buffer IN takes it for the phantom-powered ring, and the Q-filter input taps it for the resonant boost that replaces tone. All three are parallel loads on one node — no series components between them.
✓ CHECK: V1 to ground bus = continuity. Wiper (Lug 2) reads resistance to both Lug 1 and Lug 3 at mid-rotation. From the wiper you should have continuity to all three: Q Lug 3, buffer IN pad, and jack TIP. No shorts between Lug 1 and Lug 2. Tip and ring of the jack must NOT be shorted together.