Today's haul - after long break - SDA 1's

2

Comments

  • Gardenstater
    Gardenstater Posts: 2,026
    edited January 22
    1st Generation SDA 1 is supposed to have 2 SL1000 tweeters and 4 MW6501. Some early ones had a 3 pin IC connector. I think I see a hole where a 3rd pin would have been on yours.

    What model # are your MW's? Not quite good enough focus or closeup enough for me to read the #.

    If you use a pair of needle nose pliers and worry the connection slightly to break the oxidation you should then be able to pull the wire straight off. You only need to pull one off of each driver in order to get a meter reading on it. Make sure the white wires on all drivers (and tweeters) are NOT connected to the tab with the red dot.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
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    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • Mystery
    Mystery Posts: 2,543
    edited January 22
    All mid woofers (top two) on both speakers work.
    I tested with a test signal and all of them are good.

    Finally I got the wires off of the two left bass woofers and left one reads around 4.5 ohms but started at 28 ohms.
    Tested with a test signal and no sound. It's shorted.
    The right one reads open so it's also a dead one.

    So the left speaker so far has two good mid woofers and two bad bass woofers.
    Right speaker has all four good woofers.

    Will test tweeters separately with a test tone and if that doesn't work need to desolder some of the lead/s as they are soldered.
    1st Generation SDA 1 is supposed to have 2 SL1000 tweeters and 4 MW6501. Some early ones had a 3 pin IC connector. I think I see a hole where a 3rd pin would have been on yours.

    What model # are your MW's? Not quite good enough focus or closeup enough for me to read the #.
    ...
    Tweeters don't have red dot so not sure if they are wired correctly.

    Edit: MW6600X on the woofers with some hand written numbers.
    134au1ai72id.jpg

    5n492ixm92he.jpg

    Sonus Faber Concerto Grand Piano, Klipsch, B&W DM602.5, Epicure 20+, T/E 280, 100V, Polk.
    Subwoofers: Monitor Audio, B&W ASW300, Triad ProSub Bronze.
  • Gardenstater
    Gardenstater Posts: 2,026
    edited January 22
    The model # is under the word "audio" in the "polk audio" at the top of the label and it looks like they may all be MW6600X, which I believe is considered equivalent to MW6501? Weird but true.

    Whoever handwrote those dates must've had way too much coffee but I think I read 8-25-83 on one :D
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • Mystery
    Mystery Posts: 2,543
    The model # is under the word "audio" in the "polk audio" at the top of the label and it looks like they may all be MW6600X, which I believe is considered equivalent to MW6501? Weird but true.

    Whoever handwrote those dates must've had way too much coffee but I think I read 8-25-83 on one :D

    Haha... didn't even look on the printed part.
    Yes all six are MW6600X. The two that I didn't take out should be also the same.

    So basically, I epoxied two bad woofers, first for me. :smiley:

    Sonus Faber Concerto Grand Piano, Klipsch, B&W DM602.5, Epicure 20+, T/E 280, 100V, Polk.
    Subwoofers: Monitor Audio, B&W ASW300, Triad ProSub Bronze.
  • Gardenstater
    Gardenstater Posts: 2,026
    If the MW6600X is supposed to be equivalent to the MW6501 it should have a DCR of 7.75 Ohms. What reading do you get on the ones you say are good?
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • Mystery
    Mystery Posts: 2,543
    If the MW6600X is supposed to be equivalent to the MW6501 it should have a DCR of 7.75 Ohms. What reading do you get on the ones you say are good?
    The one I could pull the leads off reads 8.4 ohms.

    Sonus Faber Concerto Grand Piano, Klipsch, B&W DM602.5, Epicure 20+, T/E 280, 100V, Polk.
    Subwoofers: Monitor Audio, B&W ASW300, Triad ProSub Bronze.
  • pitdogg2
    pitdogg2 Posts: 19,502
    Pictures of problematic fast ons

    do not cut
  • Mystery
    Mystery Posts: 2,543
    pitdogg2 wrote: »
    Pictures of problematic fast ons

    do not cut
    It's just tight. I pulled one and it reads 8.4.
    Working ones are working so no need to troubleshoot.
    Top ones in this photo.
    https://us.v-cdn.net/5021930/uploads/editor/xf/zxrdptxebkpj.jpg

    Next is to check tweeters and fuses.

    Sonus Faber Concerto Grand Piano, Klipsch, B&W DM602.5, Epicure 20+, T/E 280, 100V, Polk.
    Subwoofers: Monitor Audio, B&W ASW300, Triad ProSub Bronze.
  • pitdogg2
    pitdogg2 Posts: 19,502
    Lol guess I could have scrolled up 🤦🏻‍♂️
    Tight is good. (Shut up @ken brydson )😜 In all seriousness I would remove all and hit everything with a stainless steel brush or some sort of wet/dry sandpaper just to remove any oxidation.

    I was going to recommend a awl or small flat blade to loosen. They can become stuck on by oxidation somewhat.
  • Gardenstater
    Gardenstater Posts: 2,026
    Mystery wrote: »
    pitdogg2 wrote: »
    Pictures of problematic fast ons

    do not cut
    It's just tight. I pulled one and it reads 8.4.
    Working ones are working so no need to troubleshoot.
    Top ones in this photo.
    https://us.v-cdn.net/5021930/uploads/editor/xf/zxrdptxebkpj.jpg

    Next is to check tweeters and fuses.

    It's great that you have some working and I'm sure you're happy enough with that right now. It would still be a good idea to check DCR's on all of them because the closer they are matched, the better will be your stereo center image and the closer will be the relative voicing between the two speakers.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • Mystery
    Mystery Posts: 2,543
    Checked the fuses and both stereo tweeter fuses are blown.
    Dimensional tweeter fuses are good, obviously as it was not used, so I swapped the fuses.
    If all tweeters work, I'm thinking about using SL1000 with as stereo but that means I have to switch SL2500 and make more holes. :confused:

    Sonus Faber Concerto Grand Piano, Klipsch, B&W DM602.5, Epicure 20+, T/E 280, 100V, Polk.
    Subwoofers: Monitor Audio, B&W ASW300, Triad ProSub Bronze.
  • xschop
    xschop Posts: 2,053
    Didn't someone "TL" these and make a plate to center one tweeter?
  • Gardenstater
    Gardenstater Posts: 2,026
    edited January 22
    Mystery wrote: »
    Checked the fuses and both stereo tweeter fuses are blown.
    Dimensional tweeter fuses are good, obviously as it was not used, so I swapped the fuses.
    If all tweeters work, I'm thinking about using SL1000 with as stereo but that means I have to switch SL2500 and make more holes. :confused:

    Since you don't have the IC anyway at this time, AND we know the SL2500 is NOT the correct tweeter, I wouldn't make any new (incorrectly located) holes. Before I did that I would just cut a couple pieces of aluminum plate and block off the dimensional tweeter locations until such time as I got 2 more SL1000's and an IC cable. 1/4" or even 1/8" Baltic Birch plywood may be a suitable temporary fix as well.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • Mystery
    Mystery Posts: 2,543
    ...Before I did that I would just cut a couple pieces of aluminum plate and block off the dimensional tweeter locations until such time as I got 2 more SL1000's and an IC cable. 1/4" or even 1/8" Baltic Birch plywood may be a suitable temporary fix as well.
    Yes that is an option but too much work.
    I'd rather wire the SL1000 with stereo wires at the same outside location.
    More than IC cable, I need to source two woofers as these are not usable without those.
    So what woofers will work?
    6600, 6501, what else? Anything 8 ohm Polk of that era?

    Sonus Faber Concerto Grand Piano, Klipsch, B&W DM602.5, Epicure 20+, T/E 280, 100V, Polk.
    Subwoofers: Monitor Audio, B&W ASW300, Triad ProSub Bronze.
  • Gardenstater
    Gardenstater Posts: 2,026
    I think those are your only 2 options. I suggest putting "Polk MW6501 MW6600X" in as a search term on ebay and make it a saved search. I see 3 avail. right at this moment.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • BlueBirdMusic
    BlueBirdMusic Registered User Posts: 1,564
    xschop wrote: »

    I have never seen that thread. I have some nice SDA 1A's. If I every run out of stuff to do, it could be a project.
    You Can't Resist Propaganda if You Can't Recognize It
    If the telephone doesn't ring ......... it's me
    Harry / Marietta Georgia

  • pitdogg2
    pitdogg2 Posts: 19,502
    It is not a true TL mod but its a very nice thread and well done.
  • Mystery
    Mystery Posts: 2,543
    edited January 23
    After putting good fuse for the 2500 tweeters, they work great.
    Even with bass from only one speaker, it sounds good.
    Yes, not correct tweeter but it's not an audiophile setup anyways.
    For crying out loud, I used my phone to play music.

    Need to decide if I want to make them complete or sell as is or part out.
    It's quite bit of money to get two mids and two tweeters plus IC cable.
    And as if I need more speakers than what I already have.
    Time will tell...

    Sonus Faber Concerto Grand Piano, Klipsch, B&W DM602.5, Epicure 20+, T/E 280, 100V, Polk.
    Subwoofers: Monitor Audio, B&W ASW300, Triad ProSub Bronze.
  • xschop
    xschop Posts: 2,053
    pitdogg2 wrote: »
    It is not a true TL mod but its a very nice thread and well done.

    How would the tweeter circuit need to be modded to accept the factory RD0198?
  • pitdogg2
    pitdogg2 Posts: 19,502
    Well I'm not real sure. My SDA1 signatures do have a 5.8uf cap across a resistor. I have to wonder if they also need a different inductor as well in the tweeter circuit.

    The 5.8uf cap across the resistor creates a contour circuit for the tweeter.

    Dave or Trey are much smarter than I maybe they have a better answer.
  • F1nut
    F1nut Posts: 46,296
    xschop wrote: »

    That's not even a TL mod as he was installing the RD0194.
    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

  • Mystery
    Mystery Posts: 2,543
    Quick question, how are the IC pins connected? Left to left, right to right?
    Can I use some wires with spade ends to connect pins together to make a hill billy IC cable?

    Sonus Faber Concerto Grand Piano, Klipsch, B&W DM602.5, Epicure 20+, T/E 280, 100V, Polk.
    Subwoofers: Monitor Audio, B&W ASW300, Triad ProSub Bronze.
  • xschop
    xschop Posts: 2,053
    pitdogg2 wrote: »
    Well I'm not real sure. My SDA1 signatures do have a 5.8uf cap across a resistor. I have to wonder if they also need a different inductor as well in the tweeter circuit.

    The 5.8uf cap across the resistor creates a contour circuit for the tweeter.

    Dave or Trey are much smarter than I maybe they have a better answer.

    Thanks for confirming, WMG has explained it before in good detail. IIRC, it attenuates the output as frequencies increase.
    F1nut wrote: »
    xschop wrote: »

    That's not even a TL mod as he was installing the RD0194.

    Leave it to F1.....ya just ruined the guy's last 13 yrs of "TL" pride!
  • pitdogg2
    pitdogg2 Posts: 19,502
    Mystery wrote: »
    Quick question, how are the IC pins connected? Left to left, right to right?
    Can I use some wires with spade ends to connect pins together to make a hill billy IC cable?

    Not sure I understand the question but I'll give it a try. The cable itself is straight through. What I mean is one wire is big blade and one is small. So if you think of it as positive and negative. Remember once upon a time most speaker cable had a transparent jacket? On the outside of jacket one side had a line and one side had postive symbols. Hook positive side to big blade and negative to line side or small blade.
    As I said previously the switch is in the cabinet on the plug jack. Making a cable is stupid simple. Call polk the used to sell ends or complete cable with aftermarket ends. The complete cable was 65.00 at one time.


    https://www.ebay.com/itm/Interconnect-Cable-Polk-Audio-SDA-2-and-other-SDA-Series-w-2-flat-pins-20ft-NEW/383825726469?hash=item595dcbcc05:g:0tUAAOSwpLNYB435
  • Mystery
    Mystery Posts: 2,543
    edited January 24
    pitdogg2 wrote: »
    Not sure I understand the question but I'll give it a try. The cable itself is straight through. What I mean is one wire is big blade and one is small. So if you think of it as positive and negative. Remember once upon a time most speaker cable had a transparent jacket? On the outside of jacket one side had a line and one side had postive symbols. Hook positive side to big blade and negative to line side or small blade...

    This one doesn't have pin and blade.
    Both are same size pin and there's a big hole below them.
    It looks like that hole isn't connected to anything (maybe) and it's just to orient the IC cable.
    So the question is how should those two pins be connected together?
    Outside pin on left speaker, looking from the back, connects to outside pin of right speaker or outside to inside!

    Another question is what happens if the IC leads are connected the wrong way?
    Will it damage the speaker or just the SDA side won't work correctly?

    Sonus Faber Concerto Grand Piano, Klipsch, B&W DM602.5, Epicure 20+, T/E 280, 100V, Polk.
    Subwoofers: Monitor Audio, B&W ASW300, Triad ProSub Bronze.
  • Gardenstater
    Gardenstater Posts: 2,026
    edited January 24
    Your SDA 1 is one of the earlier ones that doesn't have the large blade and the small blade. Normally the large blade would be Pin #1 and small blade would be Pin#2. Others can correct me if I'm wrong but I believe the SDA IC cable should have 2 wires and both wires carry a signal. Pin #1 on one end should connect to Pin #1 on the other end and same for Pin #2. I would identify and label Pin #1 and Pin #2 on your Left and Right speakers by using your meter and doing the following checks:

    919icbfoyrc3.jpg

    wsm9xomsr1yf.jpg

    y4cv4hkbzlnp.jpg

    z72da1gy8kwf.jpg

    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • dkfreebird
    dkfreebird Posts: 1,139
    edited January 24
    If hooked up wrong it can take out your amp or Preamp or both.

    https://forum.polkaudio.com/discussion/159532/polk-sda1-with-ports-below-tweeters#latest
    2 Channel
    Polk 1.2tl's Fully modded with dreadnought

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    Backups 2.3tl, 3.1tl, Crs+ pin/blade with stands.Monitor 5 peerless,Monitor 4 peerless,McCormack Dna 0.5 Deluxe McCormack Dna 1,Dared Sl 2000A,Dayens Ampino Rogue Magnum 66 pre
  • Mystery
    Mystery Posts: 2,543
    dkfreebird wrote: »
    If hooked up wrong it can take out your amp or Preamp or both.

    https://forum.polkaudio.com/discussion/159532/polk-sda1-with-ports-below-tweeters#latest
    That's messed up.
    It would've been so easy if they marked the pins like 1,2,3 as in xlr connections.

    Sonus Faber Concerto Grand Piano, Klipsch, B&W DM602.5, Epicure 20+, T/E 280, 100V, Polk.
    Subwoofers: Monitor Audio, B&W ASW300, Triad ProSub Bronze.
  • pitdogg2
    pitdogg2 Posts: 19,502
    edited January 24
    Dude inside you should have numbers or HNG or something close to discern. Either way you're going to have two different color wires if the green wire is on + or #1 then green wire on other side needs to be on - or #2 then wire two would be the same.
    Now I just made up the green color it could have been any color wire I'm not quite sure which color they used at this point in time cuz I rewired mine so I can't look. but I will say I just used binding post on mine and just used speaker cable and basically the switch in the connection is on the inside so that's an old RTA type socket and there should be two different wires there and you should be able to discern which one needs to go to which pin whether it be a neutrik connector or a binding post.

    Yes you can let the magic smoke out if done wrong. But seriously it's not hard to figure out.