Hamer CH-12 Wiring

Although both the B12L and CH-12 have stereo output jacks that does not mean they have a stereo output. When correctly wired, the ring of the stereo jack serves as a battery disconnect for the active electronics. Plugging your cord into the jack turns the active electronics on, and removing the cord disconnects the electronics and preserves the life of the battery. So the jack is stereo but the output is mono.

The first shipment of Korean Hamer CH-12 basses in 2000 was shipped with incorrect mono output jacks. These jacks cause the batteries to become completely drained within a very short time. This is the first page of the two-page letter that was sent to Hamer dealers by Mike Shellhammer, the National Account Manager for Kaman Music. The letter was accompanied by replacement jacks and even offered to arrange for shipping back to the customer service center in case the music store was unable to make the repair.

The second page of the letter included this diagram for how to properly install the stereo jacks. This diagram was faxed to Kaman on November 28, 2000 after the problem was recognized.

If your CH-12 is quickly draining the batteries due to it having a mono output jack, the jack must be replaced with a stereo output jack to eliminate this problem. This diagram illustrates how the new stereo jack should be wired. Unsolder the BLACK battery connector lead from the "V" volume pot and solder it to the RING lug of the stereo jack. The tip and ground lugs are wired exactly as they were with the mono jack.