2BTL Issue

normac

I performed the tl mod on a pair of 2Bs about two years ago. A subsequent static/buzzing noise seemed to have been solved with a repaired solder joint. Now, after two years, I am noticing that static/buzzing noise when deep, loud bass is played on the LH inner mid driver. I have switched drivers and speaker cables to confirm the issue is not with the driver or the amp and must be with the crossover. All solder joints have checked good. Could one of the Sonicaps be defective? Any ideas on tracing down this problem? Thanks for the help.

westmassguy

In the 2B's lo-pass stereo circuit, you have a #20 gauge, 2.5mH inductor in series with the woofer, and a 20uf Cap after the Inductor, shunting to ground. Check all the solder points for each component. Pay particular attention to where the Inductor is soldered to the circuit board, as the coil wire can fracture over time due to vibration. Make sure both Inductors are secured properly with wire ties. Check the Mate'N'Lock connectors for the woofer harness, and make sure all the internal contacts (Sockets and Pins) are clean and making good contact. You might want to apply some DeoxIT gold to the plug and socket.