PSW1200 Volume Control

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Hello all,
I have a PSW1200 that i've owned for over 20 years. I've noticed lately that when i attempt to adjust the volume via the dial on the front, it produces a scratching sound out the speakers and does not adjust the volume in proportion to the setting. Sometimes when i stop adjusting it, there is no sub volume. Sometimes the volume is extemely high, even though the dial only shows a 4 or 5. It's gradually gotten worse over the last year or so, and is now a major problem.

I've not made an attempt to remove the volume knob or test it in any way. Just wondering if anyone else has had the same situation, and whether they were able to resolve it.

Polk support was less than helpful. No replacement available, exact or otherwise, and they said they do not have technical specs for the volume control dial (what?). They recommended i look on the Polk forum, lol....

I love the speaker, and want to fix it. Any help would be welcome and appreciated!!

Thank you in advance!

Best Answer

  • ChrisD06
    ChrisD06 Posts: 886
    Answer ✓
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    The cover of the volume knob (the plastic face with the logo and LED) is capable of coming off. Facing it, just pull it straight out towards you, not too hard or the LED cable will get yanked and can break. Inside is your potentiometer. Same design as my RT3000p.

    I believe the inside of the volume dial cover has the model on it?

Answers

  • F1nut
    F1nut Posts: 49,832
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    It appears the volume knob is under the Polk Audio logo on the front of the unit...strange. Anyway, you would need to remove the volume control knob to find the specs, which should be printed on the back. It may even have the name of the manufacturer that supplied the control. Once you have that info it should be easy to search for the proper replacement.

    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • Elsie659
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    Chris,
    Thank you so much!!! It came right out just the way you said it would. Appears to be an Alpha A250K. Looks like the connections are potted, so just need to remove that without damaging anything and should be able to get it fixed up in no time.

    THANK YOU!!
    Shawn

    lni4cgsdgpqe.jpg
    p4p3oe784csm.jpg
    p4nd1lchzy6m.jpg

  • ChrisD06
    ChrisD06 Posts: 886
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    Elsie659 wrote: »
    Chris,
    Thank you so much!!! It came right out just the way you said it would. Appears to be an Alpha A250K. Looks like the connections are potted, so just need to remove that without damaging anything and should be able to get it fixed up in no time.

    THANK YOU!!
    Shawn

    lni4cgsdgpqe.jpg
    p4p3oe784csm.jpg
    p4nd1lchzy6m.jpg

    Awesome! Glad to be of help.

    Just a suggestion, and I've not tried this but I was recommended it by a local vintage audio guy, but: maybe try DeoxIT F5? It claims to be gentle on plastic and it's designed to clean pots. Perhaps all the pot needs is a cleaning.
  • pitdogg2
    pitdogg2 Posts: 24,610
    edited December 2023
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    https://www.amazon.com/Hosa-F100L-L25C-DeoxIT-FaderLube-Dropper/dp/B0018P6DPW

    https://www.amazon.com/CAIG-LABORATORIES-D100L-25C-Contact-Cleaner/dp/B0000YH6F8

    These two are all you'll ever need.
    The deoxit chris pointed to is only a 5% solution. It's 95% other stuff that evaporates away. The needle bottles are much superior in getting it where you need it.

    Now in the past most of these type of pots have carbon wipers and they do tend to build up crud. You can also try running it back and forth full range a bunch of times to try and clear it to make better contact. Canned air is also an option.
    Use the deoxit then the next day use the fader lube and if those do not help you're out of options and need to replace.
    Both run fully back and forth a good amount is helpful.

  • F1nut
    F1nut Posts: 49,832
    edited December 2023
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    $3.48
    https://www.stewmac.com/electronics/components-and-parts/potentiometers/alpha-control-pots/

    Dab denatured alcohol onto the hot glue, wait a few minutes and it will peel right off.

    You're welcome.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk