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Sony PS-B80 tonearm rewiring options

Discussion in 'Turntables' started by Harolda, Oct 31, 2017.

  1. Harolda

    Harolda Active Member

    Messages:
    450
    Location:
    Netherlands
    I am wondering what the best way is to upgrade the wiring on my Sony PS-B80 tonearm?
    The current wiring is lit in cotton and i noticed some damages in the coating giving some hum sometimes.

    The turntable has been fully restored:
    - recapped
    - all through pcb connections desoldered and resoldered
    - pcb connectors cleaned
    - pcb's cleaned
    - fully adjusted according to spec

    The tonearm is easy to rewire. The current path of the cartridge signal is:

    tonearmwire-->PCB-->relay-->RCA cable.

    The relay is not in the actual signal path but shorts the left and right signal to signal ground when engaged
    The relay is disengaged as soon as the up/down button is pressed and when the arm is located above the record.

    I have the following options:

    1) Keep the signal path as it is but only replace the tonearm wiring and use a high quality (low capacitance) phono cable. So the relay function is maintained like the original

    2) same as 1 but use rca female connectors on the back of the turntable together with a good ground binding post

    3) tonearm direct wiring to the rca connectors, not using the relay anymore

    4) tonearm direct wiring into the RCA cable like this:

    http://www.partsconnexion.com/product1011.html

    My feeling says that the last option would remove all inferences and i can shield the arm over almost the complete length to just before entering the arm.

    However option 1 and 2 maintain the original function of the relay shorting the signal when no record is played.

    What are your thoughts?

    thx for the response
     

     

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  2. Harolda

    Harolda Active Member

    Messages:
    450
    Location:
    Netherlands
    Some pictures

    Biotracer tonearm without top cover:
    IMG_2729.jpg
    Front and rear the linear motors which control to upward/downward tonearm motion

    In detail showing the signal wires and the wire to the linear motor coils
    IMG_2758.jpg

    PCB to connect the tonearm wire to the phono cable. On the back there is a signal mute relay (with shielding cover):
    IMG_2746.jpg

    and without shielding cover:
    IMG_2755.jpg

    This weekend i will check the tonearm wire again to be sure it needs to be replaced. Not a difficult job on this arm but why replace when it's not broken. the phono cable is not original. I will check that too.
     
  3. Harolda

    Harolda Active Member

    Messages:
    450
    Location:
    Netherlands
    maybe it's sufficient to add some insulators to this connection ;)

    psb80_litz_connection_original.jpg
     
  4. ebk231

    ebk231 Member

    Messages:
    71
    I am getting ready to refurb mine. I like the idea of a tonearm rewire but maintaining the mute circuit. Do you know of any particular problems I should be looking for during my refurb. I always like to replace the the VD 122x diodes on sony turntables of this era. You might want to consider doing that while working on it they are known to be troublesome.
     
  5. Harolda

    Harolda Active Member

    Messages:
    450
    Location:
    Netherlands
    I am not sure if there are any critical VD122x diodes in a PS-B80, but i will verify this. I am not keen (anymore) on replacing functional parts. I replaced certain double diodes in Sony Vfet amps, but that does not mean all double diodes need to be replaced!

    The most important for this unit are:

    0) make pictures of the complete unit into every detail, every cap, every pcb connector etc. Your unit will be different than de service manual. Look at how all connectors are attached! Read the service manual a few times and look at how the unit is assembled and try to figure out how it works

    1) Clean all switches and connector thouroughly. Check with info from step 0 and verify operation (do not yet adjust unit). Note wat is working and what not

    2) recap in a step by step approach and start with the PSU and verify the voltage rails for the Motherboard and motor. if this is not correct the electronics will go haywire and you start chasing ghosts. There are a lot of bipolars in the unit, look out for this. Also do not forget the cap at the underside of the motherboard (if there is one in your unit).

    For step 2, 3 and 4, the motherboard can easily be removed from the unit, this helps a lot in doing a proper job!

    3) Check with info from step 0 and verify operation (do not yet adjust unit). Note wat is working and what not

    4) Remove solder of through PCB connection on one side, clean and resolder. Check which solder you use and if you have to remove the flux after soldering to avoid shorts!

    5) Repeat step 4 for the other side of the PCB

    6) Check with info from step 0 and verify operation (do not yet adjust unit). Note wat is working and what not

    7) If there are any not working functions, start looking for faulty parts and replace

    8) start adjustment of the unit. Not all adjustments in the procedure are clear. I am still working on a few, especially the stylus force (offset & adjustment) and the anti skating function. Procedure: I put the unit op high with some supports under the feet of the turntable so i can check it's normal functions and also adjust the pots. I have a mirror under the unit and suffcient lighting. This works very well. I also replaced almost all adjustment pots with bourns multiturn, this helps a lot. Procedure: Take out the old pot. Measure it's resistance, adjust the new pot to the same value and solder to the PCB. This ensures that you have a good starting point fro your adjustments.

    9) Look at rewiring if you like, readjust everything, since a new tonearm wire will probably influence the forces in the arm (like anti skating) and this can adjusted with the force feedback-motion system in the arm.

    10) I verify the anti skating with a test record and oscilloscope and i would like to find out how i can set this to an optimum and how it is changing with the stylus force. But first i need a clean signal from the cartridge, hence te rewiring of the tonearm.

    Most important: take your time. Does your unit work at the moment?
     
  6. ebk231

    ebk231 Member

    Messages:
    71
    Thank you so much for that. I am no expert but I have tackled a few of these sophisticated Sony tables. I was working on my ps-x70 and stumbled onto the threads talking about the double diodes taking out v-fet amps. That is when I found a bad one in the ps-x70. I am trying to do my best to make these things last a long time as my personal table so I just change them out now. I have done so in ps-x70, ps-8750 and ps-x800. I havent even turned on my ps-b80, I got it from a reliable collector and I trust its in the state he claimed. I just finished a re-cap and service of the ps-x800 and I am working on fine tuning all the adjustments. I want to get it finished up before I open up the ps-b80. I do this just as hobbist and I only like tackling one at a time so I stay completely focused. When I do get into I will try to add info and pics to this thread so more info is out there.
     

     

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  7. Harolda

    Harolda Active Member

    Messages:
    450
    Location:
    Netherlands
    Hi ebk231,

    If you can deal with a Psx-800, then a ps-b80 is a walk in the park
    I also have a Psx-800 waiting, but the electronics in this machine is more complicated.

    I finished the rewiring on the ps-b80 and decided to have one cable from head shell connector to the rca’s.
    I also spend a few days for finalizing all adjustments using a test lp and an oscilloscope, especially to get the inside force and the azimuth angle adjusted to perfection.

    It was a huge step in sound quality after rewiring and proper adjustment of the deck. I now have a Sony xl55pro on it. Just magic.
     
  8. ebk231

    ebk231 Member

    Messages:
    71
    Hello Harolda

    I finally got started on mine and Im excited to hear it. Did you anything that need to be lubricated? Were you able to finalize your adjustments? I hope its been working great for you! 0315181938.jpg 0315181938b.jpg 0315181938c.jpg
     

    Attached Files:

  9. Harolda

    Harolda Active Member

    Messages:
    450
    Location:
    Netherlands
    No in the end nothing needed to be lubricated. The mechanism is very smooth. I also was able to adjust everything. The hardest part was the setting of the tracking force. But in the end i used a test record to give me the best setting.
    I see you have a very clean unit. I also see that you have an additional adjustment pot on the smaller PCB in the front. Does that control the drop in point on the record. I do not have this pot in my unit.
    What did you do to your unit?


    regards,
     
  10. ebk231

    ebk231 Member

    Messages:
    71
    Yes that it is the drop in adjustment. This was acting erratic and unresponsive when I got it, but it did zero balance. I did a recap on and cleaned the controls and now it wont zero balance. I havent worked on it in awhile because of time and other projects. I have been reading as many threads as possible on it and Im starting to think my main IC might be one of the issues. I had great results working on my ps-8750, ps-x70 and ps-x800 and I really hope to add this beauty to my working stable too. Im good at physically fixing an issue but diagnosis of these complex tables is whole other thing. Im persistent and wont give up even if it takes years!
     
  11. Harolda

    Harolda Active Member

    Messages:
    450
    Location:
    Netherlands
    Don’t already think it is the main IC. The mainboard has many through pcb solder pins. Al those need to be resoldered, preferably desoldered and resoldered. The main board needs to be removed (probably also for recapping) to do this. Take good pictures of the connectors, this is really important. I had some issues with the unit because one connector was not put back correct, although it seemed correct. The SM is also not exact and it will not be of help. Good luck
     

     

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  12. ebk231

    ebk231 Member

    Messages:
    71
    I did resolder the through pins, as I did on my 8750. I will double check all the connections. Thanks for chiming in Im probably gonna need more help
     
  13. Harolda

    Harolda Active Member

    Messages:
    450
    Location:
    Netherlands
    Did you make any progress? I have some issues with mine. It has been playing without issues for some months and then did not use it for one or two months. It won't drop the arm. I can't find any issues on it yet. I am going through all the measurement points in the manual at the moment.
     
  14. Harolda

    Harolda Active Member

    Messages:
    450
    Location:
    Netherlands
    Solved! the relay (RY971) controlling the signal to the tonearm drive coil passed out on me. Replaced that and now it works again like it should! It is one one those same relays that caused a lot of issues in a Sansui AU X1. I think it should be on the priority list to be replaced next to a recap! I used a Omron G5V2H 24V relay. The pinout is different so the wiring to the relay needs to be changed somewhat.
     

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