Polk Monitor 7A barn find

Hi!

Not actually a barn find, but I pulled these out of my garage where they had been gathering dust for about 15 years.

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From what I've learned here, they are a later model 7A with a single fuse and the peerless tweeter.

I have them hooked up to another gem that I rescued from myself- this one needed a full service and I was hoping the 7As would sound good with it.

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Right now one side has no sound from the tweeter and the quick fixes (fuse replacement and cleaning) didn't help. I've read some very helpful threads here and am contemplating my next move- swap tweeters? Check for corrosion at fuses (they were stored poorly)? Any thoughts/suggestions much appreciated,



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Comments

  • boston1450
    boston1450 Posts: 7,636
    edited January 2019
  • boston1450
    boston1450 Posts: 7,636
    edited January 2019
  • VSAT88
    VSAT88 Posts: 1,257
    edited January 2019
    Try moving the tweets side for side and check for DC offset of that Marantz while you are in there. Oh, and I would not even look at those speakers hard let alone move them around until both of those mid woofers were taken out and epoxied.
  • Use a piece of wire where the fuse is at in case the fuse is blown.

    If you end up removing the Tweeter from the cabinet notice that the wires are directly soldered to the tabs on the tweeters. Do not try to desolder them because the heat will make the tab fall off and ruin the Tweeter. Ask me how I know. Instead cut the wire a few inches away from tweeter.
    SDA SRS 2.3TL's
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  • Thanks for the suggestions.

    I pulled the tweeter this morning and touched the speaker wires directly to the tweeter terminals, turned bass and volume all the way down and slowly raised the volume- no sound. There was audio coming from the mid though as I left the tweeter wired. Would this invalidate the test?

    Put the multi-meter on and measured 3.9 ohms.

  • I don't think so. Unfortunately it sounds like the tweeter is blown.
    SDA SRS 2.3TL's
    Silk Audio MS-90-BT integrated tube amp
    Yaqin MS-20L integrated tube amp
    SDA 2B TL's
  • After more coffee the brain kicked in- fully removed the tweeter and meter said it was open across the terminals.

    I guess I am looking for a new tweeter. Any thoughts on the many copies out there?
  • Tony M
    Tony M Posts: 11,151
    edited January 2019
    Great speakers you have there!

    Many people here on the forum sell those tweeters now and again.

    Also eBay sells the vintage Peerless tweeters too quite often. Be patient and get an original working one.

    You might have to post more to gain trust here first though.
    Most people just listen to music and watch movies. I EXPERIENCE them.
  • tonyp063
    tonyp063 Posts: 1,083
    I own that exact version of M7s, fully refreshed per the many threads in this forum.
    You will pry them from my cold, dead, and lifeless fingers.*

    I, personally, would suggest you look for an original on the auction site.

    I heard a "replacement" version of the Peerless in some M5s & I did not care for it. Too forward, for *my* ears.

    YMMV



    *
    As you will pry my Oxford comma.
  • VSAT88
    VSAT88 Posts: 1,257
    After more coffee the brain kicked in- fully removed the tweeter and meter said it was open across the terminals.

    I guess I am looking for a new tweeter. Any thoughts on the many copies out there?

    How crafty are you with a soldering Iron ? Check the solder joints at the terminals.
  • VSAT88 wrote: »
    After more coffee the brain kicked in- fully removed the tweeter and meter said it was open across the terminals.

    I guess I am looking for a new tweeter. Any thoughts on the many copies out there?

    How crafty are you with a soldering Iron ? Check the solder joints at the terminals.

    After opening it up I quickly noticed that one of the very small wires going to the dome had broken. Soldering that gauge is well beyond my craftiness.
  • VSAT88 wrote: »
    .....until both of those mid woofers were taken out and epoxied.

    Is this to prevent the magnet slip issue?

    What are the symptoms when this happens?
  • delkal
    delkal Posts: 764
    VSAT88 wrote: »
    After more coffee the brain kicked in- fully removed the tweeter and meter said it was open across the terminals.

    I guess I am looking for a new tweeter. Any thoughts on the many copies out there?

    How crafty are you with a soldering Iron ? Check the solder joints at the terminals.

    After opening it up I quickly noticed that one of the very small wires going to the dome had broken. Soldering that gauge is well beyond my craftiness.

    Go for it................what do you have to lose? Just make sure your soldering iron is very hot and put a drop of solder on it. Touch it to the wire for one second.

    Sometimes it takes three hands to hold everything in place so try and find someone to help.
  • FestYboy
    FestYboy Posts: 3,861
    VSAT88 wrote: »
    After more coffee the brain kicked in- fully removed the tweeter and meter said it was open across the terminals.

    I guess I am looking for a new tweeter. Any thoughts on the many copies out there?

    How crafty are you with a soldering Iron ? Check the solder joints at the terminals.

    After opening it up I quickly noticed that one of the very small wires going to the dome had broken. Soldering that gauge is well beyond my craftiness.

    Balderdash, you just need to be quick about the heat with high quality solder and flux. I've done it many times with wire as small and PCB leads even smaller.
    VSAT88 wrote: »
    .....until both of those mid woofers were taken out and epoxied.

    Is this to prevent the magnet slip issue?

    What are the symptoms when this happens?

    It is. The symptom is a locked driver, little to no sound and no motion when accted upon by the PR.
  • tonyp063
    tonyp063 Posts: 1,083
    edited January 2019
    Do it. What is the worst that could happen?
    And what would the best be?
    Be careful, be quick, be sober.

    Gluing the mids to prevent magnet shift is probably the very first thing to be done with working vintage Polks.

    Many, many threads on how to do it & exactly where.
    This one has some very good visuals.

    https://forum.polkaudio.com/discussion/184312/magnet-shift-preventing-adhesive-take-a-look


  • audioluvr
    audioluvr Posts: 5,582
    Where are you located? I'd be happy to help. Send pics of your woes. People here love to help (and spend your money)
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    There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January. by Dr. Sardonicus
  • audioluvr wrote: »
    Where are you located? I'd be happy to help. Send pics of your woes. People here love to help (and spend your money)

    I'm in British Columbia.

    This seems like a very helpful place, if I attempt this repair I'll be here for advice first.

  • So I have not yet attempted a repair, but I did find an interesting option from a speaker shop in Canada. They have new old stock for $100 as well as a few used (with some dome creases) for $25 each. (all prices in CDN$, so that is $18.79/$75 in USD).

    From my understanding there will be some high frequency loss with the creased dome. Does anyone have first hand experience with this?
  • VSAT88
    VSAT88 Posts: 1,257
    Put one in and see. If they are selling Peerless at those prices, buy em all. And some would say yes, the creases in the domes will simply ruin the sound. Personally, I think not. If they are badly creased then I would avoid them though. Just my 2 pennys anyway.
  • My monitor 11 with the peerless have a crease in one tweeter, I cant tell a difference in sound side by side.
    Monitor 4.6, 5jr, 5, 7, 10, 11. RTA 8TL. RTA 11T. SDA 2B.
  • So I got one of the used tweeters and right away noticed it does not have the dimple in the dome, so I guess it did not come out of a Polk speaker. Otherwise it is in great shape (the crease is barely noticeable) and 10 minutes later it was installed and sounding great.

    I believe there are more where this came from, including NOS so if anyone is interested just send me a message.

    Next step is to epoxy the magnets. After that I might refresh the crossovers though I'm not convinced that this will make a dramatic difference to these untrained ears.
  • F1nut
    F1nut Posts: 50,543
    I've seen vintage Polk Peerless tweeters without the hole in the dome.

    You don't need trained ears to hear the difference, it's that obvious.
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    President of Club Polk

  • I believe there were some with the little hole and some without depending where they were manufactured.
    Monitor 4.6, 5jr, 5, 7, 10, 11. RTA 8TL. RTA 11T. SDA 2B.
  • F1nut wrote: »

    You don't need trained ears to hear the difference, it's that obvious.

    Thanks, that encourages me to go ahead and do it.
  • I believe there were some with the little hole and some without depending where they were manufactured.

    I was always under the impression Polk made those holes not the manu.
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  • K_M
    K_M Posts: 1,629
    edited February 2019
    VSAT88 wrote: »
    .....until both of those mid woofers were taken out and epoxied.

    Is this to prevent the magnet slip issue?

    What are the symptoms when this happens?

    If you lightly push with several fingers, around the dust cap of woofer, you will hear a very slight "shhh" scuffing sound,(Voice coil slightly rubbing on magnet) if minor, or it will be slighly hard to move and have a scraping sound if shifted more.
  • K_M
    K_M Posts: 1,629
    F1nut wrote: »
    I've seen vintage Polk Peerless tweeters without the hole in the dome.

    You don't need trained ears to hear the difference, it's that obvious.

    Having never owned the really old Polks, what is this hole for exactly?
  • delkal
    delkal Posts: 764
    K_M wrote: »
    F1nut wrote: »
    I've seen vintage Polk Peerless tweeters without the hole in the dome.

    You don't need trained ears to hear the difference, it's that obvious.

    Having never owned the really old Polks, what is this hole for exactly?

    According to Polk lore they burned to hole in the tweeter with a soldering iron to get rid of an unwanted resonance.
  • xschop
    xschop Posts: 5,000
    delkal wrote: »
    K_M wrote: »
    F1nut wrote: »
    I've seen vintage Polk Peerless tweeters without the hole in the dome.

    You don't need trained ears to hear the difference, it's that obvious.

    Having never owned the really old Polks, what is this hole for exactly?

    According to Polk lore they burned to hole in the tweeter with a soldering iron to get rid of an unwanted resonance.

    Wonder if that would help the RD0194's?
    Don't take experimental gene therapies from known eugenicists.
  • FestYboy
    FestYboy Posts: 3,861
    xschop wrote: »
    delkal wrote: »
    K_M wrote: »
    F1nut wrote: »
    I've seen vintage Polk Peerless tweeters without the hole in the dome.

    You don't need trained ears to hear the difference, it's that obvious.

    Having never owned the really old Polks, what is this hole for exactly?

    According to Polk lore they burned to hole in the tweeter with a soldering iron to get rid of an unwanted resonance.

    Wonder if that would help the RD0194's?

    No.