RTA12B Crossover: Fuse... or Fuses?

guscjr
guscjr Posts: 10
edited July 2011 in Vintage Speakers
Hi. Just joined this forum today. Have had numerous Polk models over the years. Recently sold some Monitor 10B's to get these RTA12B's...nice, very nice indeed!!

I've wondered if any of the crossover parts could or should be replaced since they've aged, but my real question is this: I noticed today that there are slots for 2 fuses on the crossover, but only 1 in each. Do they come like that from the factory or did the seller leave them out and something might be wrong....? They sound fine and I'm going to post a second thread about that and the amp I'm using a bit later. Just curious as to whether I'm getting the full performance from them or not. The crossover serial numbers are just 3 digits apart ending in 453 and 457.
Post edited by guscjr on
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  • guscjr
    guscjr Posts: 10
    edited July 2011
    Sorry guys.... I realize I'm in the wrong section, but can't yet delete this to repost it.
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  • guscjr
    guscjr Posts: 10
    edited July 2011
    Thanks for moving it to the correct forum...
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  • Outfitter03
    Outfitter03 Posts: 563
    edited July 2011
    If you look at the schematic for the original RTA 12B shown at this link:

    http://www.polkaudio.com/forums/showthread.php?t=38755

    it looks like there is on 3/4A fast blow fuse in the circuit.

    I believe there may be some threads in this section on updating these speakers. With 7 capacitors per speaker if I counted correctly and some of those being of larger value it will have some cost to the project.
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  • guscjr
    guscjr Posts: 10
    edited July 2011
    Cool. Thanks for the help. These are really great speakers.
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  • drumminman
    drumminman Posts: 3,396
    edited July 2011
    0.75 amp fuse. Though Polk has been known to have somewhat of a parts been mentality (use whatever's on hand) to build some of its speakers, that looks like something done after they left the factory.

    Your speakers would absolutely benefit from a crossover upgrade, both the uppers you've photographed and the ones attached to the binding post cups.

    I did my 12C's and the new components, once they burned in, totally transformed the speakers.

    If you like them now you'll love them with a little tweaking!

    Geoff727 did a fantastic tutorial of upgrading a pair with lots of pics. You can find it with a search.
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
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  • guscjr
    guscjr Posts: 10
    edited July 2011
    Great. I'm really restraining myself to ask another question here but think I'll post it separately. I'll look for the upgrade thread.
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