JBL L212 (212B) Bass Energizer Question

[script56]

hello. does anyone know the caps needed to repair a energizer from the l212 system?

[Odd]

L 212. Service manual was too large to upload. Here is the drawing.

55947

[script56]

thanks. now how do i go about finding out which caps are problematic? and how do you read that schematic?

[jbl_daddy]

Repairing that amp is opening a large can of worms, can you use an external amp?

[Onlyvintage]

I repaired both of my engergizer amps (I use 2 of the subs with the L212), wasn't really that difficult . The 4 large 2500uf and the 2 small 330uf were the only electrolytics in the entire amplifier. I used Philips axial lead electrolytics for the 330uf and Panasonic cans for the 2500uf, everything was ordered from DigiKey. If your need photos let me know, just give me a few days to snap a picture. After the capacitor replacement they both work perfect.

[script56]

wow those Panasonic cans are $15.00 a piece!!

[DHL]

Repairing that amp is opening a large can of worms, can you use an external amp?

You can but need to provide the EQ for the driver. Look at the feedback loop in the original. Was considering this route for my L212 bass unit, but considering the added complexity of summming L and R channels for mono, and the EQ requirements (which requires an active crossover in addition to a power amp), I decided to mod the original with more capacitance and replace bad caps elsewhere.

[DHL]

I am in the process of repairing/upgrading my L212 bass energizer as well. I am using 4 x 27,000 mfd Panasonic 63V THA caps on a separate PC board, and an outboard bridge rectifier. Removal of the original filter caps destroyed the traces on the orignal board (due to its age). The original caps had strange non-standard mounting dimensions as well. The added board fits nicely next to the original frame on the cover plate.

Also replaced those 330 mfd caps in the feedback loop with 820 mfd Panasonic radials. The originals were leaking and way below rated capacitance. Also am adding a time delay relay to mute the driver during turn on.

[DHL]

thanks. now how do i go about finding out which caps are problematic? and how do you read that schematic?

Pull the cover plate (two screws on the front and a number underneath) and look. The power supply caps are the four large silver cans sticking out of the board. Don't attempt to remove these without good (preferably vacuum) desoldering equipment. Even then, it may be tough to remove the caps and not destroy the traces on the PC board. The traces are prone to lifting due to age if they get hot. On mine, the heavy taps were bent over and soldered, making prying them up under heat difficult, even if most of the solder is removed. The caps are NLA, so finding replacements that fit the mounting pattern is not easy. In my case (see my other post) I mounted replacements on an outboard PC board and ran wire back to the power busses on the original amp board.

You can also use "computer grade" electrolytics that have screw terminals that you can wire directly without a pc board.