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Big Wili
11-16-2018, 08:29 AM
Hi, I own an Altec LF-2 subwoofer system. The amplifier has a burned out resistor (R-33) in the power supply and I need a value for that part. Anybody have schematics for the amp or a working one that they'd be willing to open and photograph to get the part value? Any help would be extremely welcome, thanks.

hjames
11-16-2018, 08:07 PM
Hi, I own an Altec LF-2 subwoofer system. The amplifier has a burned out resistor (R-33) in the power supply and I need a value for that part. Anybody have schematics for the amp or a working one that they'd be willing to open and photograph to get the part value? Any help would be extremely welcome, thanks.

I (http://audiokarma.org/forums/index.php?threads/woo-hoo-altec-lf-2-karma-and-a-protective-finish-question.78357/) did find this - not much specifics tho ...

And a link to this brochure -
https://www.usahifi.com/sites/default/files/product/513/manuals/Altec%20LF1%20LF2%20Subwoofer%20Brochure.pdf

sguttag
11-17-2018, 10:10 AM
A word of caution, a burned out resistor may indicate a problem elsewhere. A resistor can act like a like a slow burning fuse. Sometimes it is just poor design, Crown, for instance, on their D150 line has a 1/4 watt resistor running at .24 watts...depending on your line voltage and the variations on other parts, it will run pretty much at its capacity and will slowly, over the course of years, burn up. When I was servicing them, I'd replace with 1/2-watt on inspection (the PCB would darken with age due to the heat too). But in most designs, if a resistor burns up, I tend to look for WHY before replacing it. You might find something shorted down wind that is causing the excessive current through the resistor.

Mr. Widget
11-17-2018, 10:29 AM
My thought too.


Widget