Yamaha B-2 restoration journey

Discussion in 'Yamaha' started by Mr. Yamaha, Nov 16, 2016.

  1. Uncle Paul

    Uncle Paul AK Subscriber Subscriber

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    I did that for all the boards I'm working on (without reversing the components) and marked the values as I removed the components. It's the only way I can keep this 100% straight and no or no room for mistakes on these. I'm somewhat lysdexic so i can read backwards just as well as forwards (or mirror, or upside down, etc.). Nice job and a lot of work!
     
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  2. Mr. Yamaha

    Mr. Yamaha Yamaha Junkie Subscriber

    Messages:
    408
    Location:
    Haarlem, The Netherlands
    A small update here. Less time to spend on the B-2 as the girlfriend returned home after a 6 months lasting internship abroad. You know how it goes when the boss returns home :biggrin:

    I had some time to re-mount the VFET's the proper way, with silicone (non conducting) thermal grease.

    [​IMG] [​IMG]

    Also found a 'new' power switch, I actually stole it from my CT-600. I combined it with the well known Triac switch solution.

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    I also had to replace two components on the power board due to new insights. Replaced C222 with a PP film cap and TR216 with a new Zetex transistor.

    [​IMG]

    And I installed some new CMC RCA sockets with new shielded wires for direct input in the driver boards. Again, the changes made are reversible.

    [​IMG]

    Next up: reinstall the driver boards as is and fire the B-2 op. Exciting :naughty:
     
  3. Bert 1100

    Bert 1100 Well-Known Member

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    Planquiri !
    Nice!...VERY nice !
     
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  4. belgianbrain

    belgianbrain AK Subscriber Subscriber

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    Nice. Can we see a picture of the input jack board and how you managed that?
     
  5. rottalpha

    rottalpha Yamaholic Subscriber

    Messages:
    898
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    Great work!

    I am using similar RCA's. Love the style and sturdiness.
     
  6. rottalpha

    rottalpha Yamaholic Subscriber

    Messages:
    898
    Location:
    Middle of Crook County
    let's hope not like these:
    IMG_20170309_113005406.jpg IMG_20170309_112940652.jpg

    :D:D
     
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  7. belgianbrain

    belgianbrain AK Subscriber Subscriber

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    Yeah, that is why I just drilled holes and installed new ones. I would be impressed to see a pretty way of handling that task.
     
  8. Vint Age

    Vint Age B-1 With Yamaha

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    2,058
    YIKES!
     
  9. rottalpha

    rottalpha Yamaholic Subscriber

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    898
    Location:
    Middle of Crook County
    :biggrin:
     
  10. Mr. Yamaha

    Mr. Yamaha Yamaha Junkie Subscriber

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    408
    Location:
    Haarlem, The Netherlands
    I can't take a good pic, because the back panel is reinstalled already. But, my solution was really simple and did not involve any mutilations.

    Because I went for the direct input and I will only use DC mode, I bypassed the input board completely, except for the meter section. So, I desoldered the small black board with the original RCA sockets and mounted the pcb in it's original place. I cut off and crimped the original wires, so they can be reinstated in the future.

    Also due to the bypass option, I lost input selection (would never use that anyway). Hence the RCA's of Input 2 are not connected and act as dummies to fill up those chassis gaps. So the RCA's of Input 1 are directly wired with new screened wires to the driver boards.

    I made these choices, because in my opinion it was the only way to combine these 'tweaks' with the reversibility of it.

    Yes they are great, I really like the construction of it. Especially the nut that goes on it from the back (input side). Tip: when you buy the CMC sockets, buy the $10 fasten tool with it. I bought these at HFC and they didn't mention the tool. Ended up scratching the nuts with pliers, even though I used cloth. So I ordered the tool and got 4 new nuts for free directly from CMC. Great customer service :thumbsup:
     
  11. rottalpha

    rottalpha Yamaholic Subscriber

    Messages:
    898
    Location:
    Middle of Crook County

    I meant to tell you...it looks like you have the inputs reversed. Left is usually White and Right is usually Red. It'll work either-way, just a matter of preference I guess.
     
  12. Mr. Yamaha

    Mr. Yamaha Yamaha Junkie Subscriber

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    408
    Location:
    Haarlem, The Netherlands
    Yes I know, but I'm a bit of an autist / perfectionist. See this pic, maybe you can guess why I put the red RCA's on top :p

    IMG_3711.JPG
     
  13. rottalpha

    rottalpha Yamaholic Subscriber

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    898
    Location:
    Middle of Crook County
    yeah, can't blame you...dunnit myself once too for the same reason, but ended up regretting it 'cause later I was mixing the inputs. besides, your tops match but what abt the bottoms :rolleyes:
     
  14. rottalpha

    rottalpha Yamaholic Subscriber

    Messages:
    898
    Location:
    Middle of Crook County
    could you please tell me the distance between the back of the PSU board and the underside of the cover...I guess measuring to the back plate lip....that is if your unit is still with the hood off.
    I ended up moving bunch of those power resistors to the back of the board...same for the trimmers..I guess I should have worried about the distance before :biggrin:
    or I could measure the distance from another unit, but I am just lazy...crap, it looks like is gonna be close.
     
  15. Mr. Yamaha

    Mr. Yamaha Yamaha Junkie Subscriber

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    408
    Location:
    Haarlem, The Netherlands
    Black and white are equal to me, but those redheads aren't :p

    I'll measure when I'm back at it!
     
  16. Mr. Yamaha

    Mr. Yamaha Yamaha Junkie Subscriber

    Messages:
    408
    Location:
    Haarlem, The Netherlands
    The back was off today, so I made some pictures:

    IMG_3774.JPG IMG_3775.JPG
     
  17. Mr. Yamaha

    Mr. Yamaha Yamaha Junkie Subscriber

    Messages:
    408
    Location:
    Haarlem, The Netherlands
    An (for me major) update here. I installed the driver boards as-is, wired the RCA's straight to them.

    IMG_3700.JPG IMG_3701.JPG IMG_3702.JPG IMG_3703.JPG

    After that I triple checked everything and went for the first power-up.

    I was a bit nervous obviously.

    IMG_3778.JPG

    Dialed the bias pots fully CCW, hooked the meter on the +85 rail and fired it up....

    Clang!

    That was the relay, nice. +85 and -85 were 0,5 V off, adjusted them to +85.

    IMG_3779.JPG IMG_3780.JPG

    After that I dialed in the bias pots without a hassle to 50 mV and the DC offset to 0 mV.

    Re-checked the same values and it was still OK.

    So I hooked the B-2 to my C-4 and went for a listen session.

    Man, what can I say, Steely Dan in the room :music:

    IMG_3781.JPG

    Next up: the driver boards and the meter board.
     
  18. Uncle Paul

    Uncle Paul AK Subscriber Subscriber

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    Location:
    Portland, OR
    Outstanding!!! :beerchug:
     
  19. rottalpha

    rottalpha Yamaholic Subscriber

    Messages:
    898
    Location:
    Middle of Crook County
    Great job :bigok:
     
  20. amr2

    amr2 Active Member

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    Great job!!!!
     

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