Tales of the Turntable

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  • rhomanski
    nowhere man
    • Dec 2009
    • 5157
    • U S of A

    #1

    Tales of the Turntable

    I've built a top of the line stereo system by Sansui from 1976. A BA-3000 power amp, a CA-3000 pre-amp, a TU-9900 Tuner, with 2 pair of SP-L700 speakers. To finish it off I bought two SR-717 turntables.

    The first table came with a Sansui SC-38 cartridge, the one that came with the table. It had no stylus or needle. I used a spare ortofon cartridge until I bought a stylus for it. All I could find was a generic conical needle. I was impressed with the sound none the less.

    Found another table eventually. It was in better shape when shipped than my first. Unfortunately, the seller shipped it wrapped in soft foam. At some point it was dropped the foam crushed and the full weight of the table landed on one corner of the wood side. It broke off the fake wood trim and crushed the particle board. I glued the fake wood back on and hid the damage as well as I could. Otherwise it's pretty good. It came with the original cartridge as well.

    Neither came with the lateral weight for the arm, which many say isn't necessary. I found some from other tables for sale and used them. I bought a Technics anti-skate weight for the second table. I had to cut the string to a better length but it works good. I couldn't set up the second table for now so I set it off in storage. I found an elliptical diamond for it in Denmark.

    Recently I put on a new record and it sounded like popcorn popping in the background. I finally discovered the needle had split in two like a bad tooth. So I grabbed the other cartridge and carried on. Fast forward to the next day and when the record ended I turned the player off and grabbed the record. It was still spinning in my hand.

    I had to unplug it to shut it off. So back to ebay I go. I found a guy parting one out which I have never seen before. Apparently it was a shipping problem and the arm was broken. So he refunded the money and parted it out. I got most of the parts he was selling. The arm board with the switch.
    Plus the entire motor and power supply. I'm using the back up one now while the broken one is in storage.

    Checking ebay for my parts I found another one for $200 less than all the others and supposedly working. I thought at worst it could be a parts unit since I couldn't get the wood end piece. It seems to be in good shape though. I might use it with a Sansui AU-717 integrated amp. Surprise surprise, it came with a Shure V15 TYPE IV cartridge. No stylus though so I just ordered a hyper elliptical from JICO in Japan.

    I can't wait for it to come, it's like Christmas. The V15 is supposed to be about the best Moving Magnet (MM) ever made. The Sansui cartridges I got on the others are basically a rebadged Excell ES-70 and no slouch in their own right but not as well thought of as the Shure. They're Moving Iron too (MI).

    A few pictures to help out.
    Attached Files
    sigpicThe Sky Is Falling
  • rhomanski
    nowhere man
    • Dec 2009
    • 5157
    • U S of A

    #2
    Re: Tales of the Turntable

    To continue the saga: I got the Jico in from Japan and it does make the Shure sing. Really nice sound. I'm still using it on the backup table.

    I rebuilt the boards on the motor and steel plate that I got off ebay and then started on my original table. It always took ten minutes to get to full speed and hold it. Might be a motor problem or a problem on the boards. I started to rebuild the boards to find out. I soon found out it was a newer design than the one from ebay. It has one less board and several polarized capacitors were replaced with bi-polars. Back to Mouser. I installed the bi-polars when I got them. Replaced 6 transistors which feed the coils of the motor. 3 are sensing, 3 are starting. All had the black plaque. I replaced all the diodes with new and then thought I would try it.

    To replace the tonearm board, I had to remove the arm completely. I noticed the insulation on the wires was starting to get brittle. Everybody brags on Litz wire so I ordered some. Plain copper, not silver. They wanted more than $150 for the silver. I got the tonearm rewired and reassembled the machine. I left the bottom plate hanging out so I could do the course adjustment on the speed pots on the circuit boards since I replaced the pots with Bourne single turns. I put the unit on four cans of chili to elevate it. After turning it on I found it still took 3 minutes to get up to full speed, better but not as good as my others. They only take about two seconds.

    It ran stable once warmed up. I thought I might replace the last 4 transistors though, the driver transistors. 3 of them are 2sd330e's and the fourth is a 2sb514e. They have a 50 volt rating and an hfe of 150. Looking online I found the recommended replacement is a tip32a and a tip31a, the a means they're 60 volt. Both only have an hfe of 25 though. So I looked around, I have some 2sc1173ytu's with an hfe of 231, so I put them in. They are only 30 volt but the circuit is 20v. They didn't help much at all. I have a complement, the 2sa473ytu coming from Mouser today, for the last one, we'll see.

    I found the microswitch on ebay NOS for $6 or so. Don't know what it's life span is. The old old switches usually had about a million actuations MTBF. These are a different model but look the same and from the same company.

    I had an old Pickering cartridge with a new needle laying around, I put it in a headshell and mounted it. I've been listening to it for a few days now sitting on it's cans of chili. Waiting on that last transistor. It has 6 more transistors on the board, 945's I have plenty of them in stock.

    I went looking for the op amp this morning. Found a place in California that said they have it. They only want 62 cents a piece but have a $50 minimum. I looked and saw they stocked a couple STK modules from the late eighties early nineties so I threw them in and found they have some dual transistors, the 798, so I ordered six of them. Paypal said they would be shipped from Canada. The name was Chinese, I thought oh boy they're probably all counterfeit. Shoot! Only thing to do is wait and see.

    If the problem turns out to be a worn motor, I'll just use it as it is till it dies and then put the spare motor in. Luckily my other two are working fine. Service Manuals attached.
    Attached Files
    sigpicThe Sky Is Falling

    Comment

    • rhomanski
      nowhere man
      • Dec 2009
      • 5157
      • U S of A

      #3
      Re: Tales of the Turntable

      Well nothing helped with that motor, it's about gone. I decided to put the other motor from Ebay in it. But first, I decided to replace the fake plastic wood veneer with real wood. I got some black walnut and got some tools and potions and preparations. I even ordered some grain filler. That's a saga. They shipped three cans by UPS. All three were damaged in Memphis. The first two were completely crushed, the last had been turned into a square can. It had a crack on one corner and some filler came out but it dried and sealed the crack. Too late though, I decided it was smooth enough after using 1000 grit sandpaper on it. I used some danish oil mix. Stain, linseed oil, and polyurethane all mixed together. Came out nice.

      Finally started reassembling it, got the arm on, then installed the new motor. Set it up on my chili cans and got ready to set the new speed pots on the board. It came up close to speed but didn't want to adjust. Finally it quit adjusting at all. I pulled my new pots and checked them, found no problem. They feed the dual op-amp, so I replaced it real quick. It's now working good. I listened to two records this morning and it worked flawlessly. I'll leave it on the chili cans for a while yet and if no more problems, put it all back together and start the next.
      sigpicThe Sky Is Falling

      Comment

      • goontron
        5000!
        • Dec 2011
        • 4108
        • US

        #4
        Re: Tales of the Turntable

        Gah! Phono repair... What a PITA! I would rather be trying to rebuild a frozen tuning capacitor...
        Things I've fixed: anything from semis to crappy Chinese $2 radios, and now an IoT Dildo....

        "Dude, this is Wyoming, i hopped on and sent 'er. No fucking around." -- Me

        Excuse me while i do something dangerous


        You must have a sad, sad boring life if you hate on people harmlessly enjoying life with an animal costume.

        Sometimes you need to break shit to fix it.... Thats why my lawnmower doesn't have a deadman switch or engine brake anymore

        Follow the white rabbit.

        Comment

        • rhomanski
          nowhere man
          • Dec 2009
          • 5157
          • U S of A

          #5
          Re: Tales of the Turntable

          I got one of those too, if your volunteering?
          sigpicThe Sky Is Falling

          Comment

          • kaboom
            "Oh, Grouchy!"
            • Jan 2011
            • 2507
            • USA

            #6
            Re: Tales of the Turntable

            ^- Yeah, jackass, "thanks for sharing."



            Go find another forum to use as whitespace.
            Attached Files
            "pokemon go... to hell!"

            EOL it...
            Originally posted by shango066
            All style and no substance.
            Originally posted by smashstuff30
            guilty,guilty,guilty,guilty!
            guilty of being cheap-made!

            Comment

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