Polk 7A crossovers seem odd

Anyone seen crossovers like these in 7As? I'm thinking about recapping them, but not sure yet because they sound pretty darn good as is. Just wondering if there's anything odd with these because I've not seen any pics similar to these anywhere. Thanks

x3mjxs2u5rtq.jpg

Comments

  • K_M
    K_M Posts: 1,627
    Those appear Home made. If they are not, Yikes!
  • pitdogg2
    pitdogg2 Posts: 24,477
    we really need to see more pictures to determine whether or not they are home made. Maybe some VERY early Polk monitor 7's did in fact have this set up. What does the binding cup look like? What are the drivers numbers?
    We all know there was some strange stuff in the early days at Polk Audio.
  • FestYboy
    FestYboy Posts: 3,861
    If need be, I could crack open one of my MODEL 7s to compare (very early production).
  • dkfreebird
    dkfreebird Posts: 1,180
    This is a pic of some early 10 boards I had so anything is possible. :)
    ka1ys3tbg7ft.jpg
    2 Channel
    Polk 1.2tl's Modded with dreadnought
    Musical Fidelity M6Si
    North Star Intenso Dac
    Auralic Aries Mini Streamer
    Oppo 103
    Pangea PC
    Wireworld Equinox 7 interconnects
    Wireworld Equinox 7 Speaker Cables and Jumpers

    Backups 2.3tl, Crs+ pin/blade with stands.Monitor 5 peerless,Monitor 4 peerless,Polk R200,McCormack Dna 0.5 Deluxe McCormack Dna 1,Dared Sl 2000A,Dayens Ampino Rogue Magnum 66 pre
  • Viking64
    Viking64 Posts: 6,646
    Why do I suddenly have a craving for graham crackers?

    86bgnruuqfde.jpg
  • pitdogg2
    pitdogg2 Posts: 24,477
    dkfreebird wrote: »
    This is a pic of some early 10 boards I had so anything is possible. :)
    ka1ys3tbg7ft.jpg

    Then they are legit! Same cap and bobbin spool inductor.
  • tjw141
    tjw141 Posts: 9
    I've already recapped them, just used Dayton capacitors since parts express is right down the road. Once I took the old ones out, the 33 read around 40 on my capacitor meter, and the 12 read around 14.

    No cup in the back, have to remove the passive to get to it. Appears to look a lot like dkFreebird's, with the little piece of plywood under the board. These are 7As with serial numbers of 03093 and 03049 so I'm guessing pretty low. One of the midwoofers rubber surround split, so I found a good deal on 2 6500s and put those in, keeping the original 2 for backups, but I'd have to refoam one of them.

    uncropped pic below, you can see where the connectors come in from the posts on the back. Some mortite around the wires. Things are sealed tight, too.

    tio06v7g2hg3.jpg
  • tjw141
    tjw141 Posts: 9
    Here's the back:

    rmnbwkqdtvi3.jpg
  • K_M
    K_M Posts: 1,627
    wow, literally a scrap of particle board stapled to the back.
    You might have almost pre-production speakers!
  • pitdogg2
    pitdogg2 Posts: 24,477
    K_M wrote: »
    wow, literally a scrap of particle board stapled to the back.
    You might have almost pre-production speakers!

    Doubt it they had a hole size for something. pre-production I would think would have holes drilled through the back just for the binding post and fuse.

    At least that is my take on it...
  • heiney9
    heiney9 Posts: 25,053
    edited May 2018
    Many of the early Model Polk's were DIY, so to speak. Sandy and Matt probably did most of the x-overs by hand in the early days. A) pc x-over boards weren't that popular in the 1970's B.) They were expensive for a start-up like Polk. Much cheaper to grab a piece of particle board and do point to point. Plus it allowed them to experiment more easily.

    Also Polk had a history of "going with what's on hand". So you will see some variation is parts/values used across generations of speakers sometimes.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
  • txcoastal1
    txcoastal1 Posts: 13,124
    Those crossovers are probably worth more since Matt and Sandy’s hands actually touch them
    2-channel: Modwright KWI-200 Integrated, Dynaudio C1-II Signatures
    Desktop rig: LSi7, Polk 110sub, Dayens Ampino amp, W4S DAC/pre, Sonos, JRiver
    Gear on standby: Melody 101 tube pre, Unison Research Simply Italy Integrated
    Gone to new homes: (Matt Polk's)Threshold Stasis SA12e monoblocks, Pass XA30.5 amp, Usher MD2 speakers, Dynaudio C4 platinum speakers, Modwright LS100 (voltz), Simaudio 780D DAC

    erat interfectorem cesar et **** dictatorem dicere a