Spectra 2200, Dissembling speaker

Read more on the Acoustat Spectra 2200 in our home audio section

Gary Hubbard2010-02-16 03:38

For Andy Szabo: I may have a wiring short on the back of one of my Spectras - as evidenced by a suddenly appearing black smudge 6 inches up from the interface. If there is a short there it evidently (according to my local audio Dr.) took out the rail fuses in a B&K ST202. What I am wondering is the procedure for taking the speaker apart to find the short. Since I put it together (new) 19 years ago, I don\'t remember the sequence. Help, Andy!!

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Andy Szabo2010-02-16 17:36

Is the black smudge on the grille cloth? If so, this might indicate a short in the high voltage wiring inside the panel frame. The black smudge could also be from smoke that curled up from the interface through the frame.

First, get someone to help you disassemble the speaker. After allowing the speaker to discharge for at least several hours, remove the two screws on either side of the interface box. Be careful - the panel is now disconnected from the base. Gently pull the panel forward, being careful not to scratch the wood base. Disconnect the colored wires from the interface by pulling the pins straight out from the connectors. The panel is now free and can be set aside.

If the speaker is a 2200 (with the decorative wood & brass strips along the sides), you\'ll need to pry off the wood from the sides of the speaker. Detach the grille cloth at the bottom of the speaker by removing the staples, and slide the cloth up until you can see the trouble area. If you see burnt wires, you can probably repair them by removing the burnt section and re-splicing, covering each splice with heat shrink tubing.

I will say that wiring problems inside the panel are rare, so you should first look for signs of damage inside the interface before disassembling the panel. Unfortunately, removing the decorative strips tends to be a one-way proposition. You can re-attach the wood after removing the brass strips and nails underneath, but the brass strip will be damaged in the process. If you read my piece on rehabilitating my Spectra 4400\'s, you will see I had the same problem, and I have yet to find a suitable replacement for the brass trim.
(And let the record reflect I had a big arguement with Marketing about those brass strips, knowing that they would interfere with repairs!)

You may also need to replace the grille cloth after this, since it is usually very difficult to re-staple the old cloth back into place. New factory-spec cloth is available: see the parts section.

Do write again if you have further questions, and please let me know what you find as the problem: I am curious to learn what caused your fuse-blowing and black smudge.

Gary Hubbard2010-02-28 21:57

Hello Andy: I am adding a picture of the alleged \"burn mark\" on the back of my left hand Spectra 22 (not 2200). It was the left side that did not want to play when I was having trouble with the pre-amp and amp.

Andy Szabo2010-04-16 02:41

Our webmaster sent you my address so I could look at the photo, but I haven\'t received it. Did you figure out your problem, or do you still need help?

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