Uncle Paul's B-2 Rehab

Discussion in 'Yamaha' started by Uncle Paul, Mar 17, 2017.

  1. Mr. Yamaha

    Mr. Yamaha With Kenwood Subscriber

    Messages:
    546
    Location:
    Amsterdam Area, The Netherlands
    Yeah, remember, I have never overhauled an amp before, let alone a B-2 :p

    I have no experience with a dirty chassis, as mine was completely clean. Some small dust particles were removed with compressed air and the transformers were made dust free with a damp cloth.
     
  2. clinic-audio

    clinic-audio all on YAMAHA untill 1990

    Messages:
    1,634
    Location:
    France
    A really dirty chassis is easy to clean as a new !

    dirty-01-R.JPG


    Dirty-02-R.JPG

    Dirty-03-R.JPG


    now the cleaned one

    new-01-R.JPG

    new-02-R.JPG

    new-03-R.JPG

    nice no ?
     
  3. Mr. Yamaha

    Mr. Yamaha With Kenwood Subscriber

    Messages:
    546
    Location:
    Amsterdam Area, The Netherlands
    Maybe it helps when you tell Uncle Paul how you cleaned it? ;)
     
    Uncle Paul likes this.
  4. Vint Age

    Vint Age B-1 With Yamaha

    Messages:
    2,097
    Nice yes!
     
  5. Uncle Paul

    Uncle Paul AK Subscriber Subscriber

    Messages:
    1,559
    Location:
    Portland, OR
  6. clinic-audio

    clinic-audio all on YAMAHA untill 1990

    Messages:
    1,634
    Location:
    France
    this is not with a cleaner , this is chemical bath and after re-galvanized .
    It is brand new
     
    Uncle Paul likes this.
  7. Uncle Paul

    Uncle Paul AK Subscriber Subscriber

    Messages:
    1,559
    Location:
    Portland, OR
    Beeeuuuutifuuuulllll....

    Hmmmmmm......

    If I can't shine mine up I might give this a try:


    After dipping in muriatic acid to remove the old finish.
     
    Mr. Yamaha likes this.
  8. Oilmaster

    Oilmaster Ozzy Subscriber

    Messages:
    1,004
    Location:
    Paris & The Hague
    So why do you say "now the cleaned one" then ?

    When posting your results, why do you always show off but give no information/methods etc?

    And BTW, this is somebody's else thread about his B-2 project, in which you again put massive results of yourself.
    Why don't you start your own threads instead?
    Hijacking is the word.
     
    Last edited: Mar 21, 2017
    Mr. Yamaha likes this.
  9. Mr. Yamaha

    Mr. Yamaha With Kenwood Subscriber

    Messages:
    546
    Location:
    Amsterdam Area, The Netherlands
    :D
     
  10. belgianbrain

    belgianbrain AK Subscriber Subscriber

    Messages:
    1,168
    Location:
    Greater Toronto Area, Canada
    You guys are too irritable.

    Everyone go have a good Trappist and come back. I will too, just for kicks. :D
     
    Last edited: Mar 22, 2017
  11. rottalpha

    rottalpha Yamaholic Subscriber

    Messages:
    1,106
    Location:
    Middle of Crook County
    If yo
    If you have access to an ultrasonic cleaner that is large enough, you might not need to mess with acids
     
  12. Uncle Paul

    Uncle Paul AK Subscriber Subscriber

    Messages:
    1,559
    Location:
    Portland, OR
    I don't have access to a cleaner that large. If I go that route I can get an inexpensive Sterilite box at home depot that has a 2" clearance, then line with 6 mil polyethylene sheeting - I have some tacky glue that can hold it to the sides, but will also let me pull it away when needed. Then change out each sheet as I move through each step - remove plating, neutralize the acid and dispose, plate with Zinc using a car battery hooked up to a charger for the current, dispose of salt bath, swap liners again and dip in chromate solution then air dry.
     
  13. Mr. Yamaha

    Mr. Yamaha With Kenwood Subscriber

    Messages:
    546
    Location:
    Amsterdam Area, The Netherlands
    Is your chassis rusty or just dirty?
     
  14. Uncle Paul

    Uncle Paul AK Subscriber Subscriber

    Messages:
    1,559
    Location:
    Portland, OR
    It looks a lot like the "before" chassis posted by @clinic-audio. I can get it clean, but only the areas covered by the transformers look new. I could probably live with it, but am kind of intrigued by making it look "factory fresh". Obviously, I'll have to experiment on some galvanized metal before doing the chassis - IF I decide to go that route. Since I have another B-2 as well as an M-4 to rehab the cost of the chemicals per chassis won't be too bad.

    Still pondering... I'm both anal and binary about things - I'm either all the way "on" and examining everything in minute detail, or I'm "off". A B-2 is worth being "on". I even removed the old solder flux from under the bridge rectifiers left over from when they were made - something nobody will ever see but that I know would be there.

    On another note the parts I ordered from Mouser are arriving today, so I can finish out the PSB and ECB
     
    Mr. Yamaha likes this.
  15. Uncle Paul

    Uncle Paul AK Subscriber Subscriber

    Messages:
    1,559
    Location:
    Portland, OR
    Would these caps also work as replacements for C201 - C204, C217 & C218? I'd like to replace with polypropylene as in @Mr. Yamaha 's thread. Unfortunately the only 0.01uF/630V purpose pp capacitors that I can find in stock have the square plastic covers that are out of place in appearance:
    upload_2017-3-26_12-4-39.png

    From what I can find the difference between microwave (like the Panasonic ECW's) and general purpose capacitors from what I can find is that microwave capacitors have higher tolerances:

    "Microwave capacitors are used as tuning elements, or as components in simple or complex filter structures. Used as a tuning element, a high tolerance is often required on a low capacitance value. Used as a DC block or bypass, usually all that you will care about is a that your RF signal sees a low impedance."​

    https://www.microwaves101.com/encyclopedias/capacitors#background

    Am I missing something?
     
  16. Oilmaster

    Oilmaster Ozzy Subscriber

    Messages:
    1,004
    Location:
    Paris & The Hague
    The issue with those boxed capacitors is:
    1) the very short legs
    2) the small pitch (distance between legs)
    Which makes them hard to fit in, and often results in clumsy works.
    So I think you won't be able to do a nice job by using those.

    And, IMHO, aesthetically they don't belong in a vintage Japanese amp, but that's your decision.
     
  17. Uncle Paul

    Uncle Paul AK Subscriber Subscriber

    Messages:
    1,559
    Location:
    Portland, OR
    We are on the same page here regarding aesthetics and proper fit. Would the Panasonic ECW-F6103JL work for these caps - it's the same one you recommended for the diode snubbers and C251/C252?

    Thank you so much for all the valuable input you have given so far.
     
  18. Oilmaster

    Oilmaster Ozzy Subscriber

    Messages:
    1,004
    Location:
    Paris & The Hague
    yep, the same.
     
    Uncle Paul likes this.
  19. belgianbrain

    belgianbrain AK Subscriber Subscriber

    Messages:
    1,168
    Location:
    Greater Toronto Area, Canada
    Why do think you need 630V?

    I think the highest DC voltage in this amp is +/- 85VDC.

    There is a wealth of choice of 0.01uF polyproylene caps, and nearly all will take 100V. Panasonic, Wima, the list goes on...
     
  20. Uncle Paul

    Uncle Paul AK Subscriber Subscriber

    Messages:
    1,559
    Location:
    Portland, OR
    Whenever possible I meet or exceed the original part. In this case the originals are 0.01 uF/630 V mylars and I would like to replace with polypropylene. Looking at all general purpose 0.01 uF PP caps that have 10mm lead spacing there are still few non "WIMA style" caps that I can purchase singly.

    Looking more closely at the power circuit (which I should have done before I asked), these are all used as diode snubbers so I am going to go with the same ones here that @Oilmaster had recommended for the Electrolytic Capacitor board.
     

Share This Page