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Sansui 3000a Recap question

Discussion in 'Exclusively Sansui' started by dirtman, Sep 13, 2010.

  1. dirtman

    dirtman The Dirtman Subscriber

    Messages:
    185
    Location:
    Richmond VA
    I am about to embark on a recap of my 3000A and am in the process of compiling a parts list. I have read many threads on recapping and I know Sam Cogley did one just like this but I still have a couple quick questions. I do not want to get involved in the tuner section if I can help it. The tuner works great and seems to be aligned almost perfectly. Here is a list of the other boards on the service manual that I am looking at. The big caps are obvious targets. There are 5 of them. Which boards should I concentrate on?

    1. EQ Board
    2. Control Amp
    3. Driver Board
    4. Pre Power Board
    5. Ripple Filter Board

    There is also an axial cap near the transformer that is 1000uF 10wv. Should that go as well? I have a pic of it attached. I also noticed a very small cap(1uF 25V) located on the selector switch. Has to go to?

    One last question. On the Pre power board, there does not appear to be any elec caps, only the flat green ones. Is it safe to assume these are ok?

    Thanks for any insight!
     

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  2. dirtman

    dirtman The Dirtman Subscriber

    Messages:
    185
    Location:
    Richmond VA
    Well I have gone ahead and made a list of every cap on all the boards I listed above and found the closest values I could get on Newark and PE. I will post the list(spreadsheet) as a PDF once I know it's accurate for future reference. Still hoping for some advice before I place the order.
     
  3. KlausDK

    KlausDK Active Member

    Hi

    Do you have the servicemanual and the later service bulletins on the output section? If not PM me for a copy.

    I would leave the green ones and concentrate on the electtrolytic caps. For the bigger caps you mention, I would try to find a physical size (diameter) match, in order to use the old mounting brackets, this would probably mean that you would have to increase capacity around 50 %, which is OK for those caps.

    BRgds Klaus
     
  4. Sam Cogley

    Sam Cogley Last of the Time Lords Subscriber

    Messages:
    30,672
    Location:
    SW Missouri
    I used some rubber weatherstrip tape as a "filler" to get the PS caps to fit in the old brackets. Sansui used some very weird cap values in there, you'll just have to get as close as possible on modern retail stock caps.

    If memory serves there are a handful of axial electrolytic caps hiding on the underside of the boards, possibly in the power supply.

    As Klaus said, make sure you do the amplifier output modification, or you'll risk setting speakers on fire. It requires replacement diodes and some caps, the information on the parts needed should be in one of my old threads.
     
  5. dirtman

    dirtman The Dirtman Subscriber

    Messages:
    185
    Location:
    Richmond VA
    Thanks for the reply. Yes.. The output coupling was the first thing I looked for when I opened it up. It was done and done well from what I can see. The available PS caps are smaller in diameter by about 1/2". I was able to find the correct uF value for the 1000uF cap but the voltage is 100v vs. 50V. That should be fine from what I have read. The other 4 caps I found are 3300uF 63V as opposed to the original 3000uF 50V. The balance of the replacements are all within 10-20% of original value. Most are from PE(xicon) and the PS are from Newark(UNITED CHEMI-CON). I will only have to combine two sets of parallel caps. I checked the back side of the board and I think I can fit the additional caps there.

    Klaus - Thanks for the SM offer. I have the manual for the 3000 and, from what i can see with my untrained eye, it seems to match up fairly well. I found a couple differences in it and am not sure if its a 3000 vs 3000a problem or just a mistake in the SM. Cap count on the ripple filter board was off by one cap. No biggie tho since I compaired values as I went and most were spot on. If you think I would benifit from having the 3000a sm, please let me know. Greatly appreciated.

    Sam - I read all your threads about your 3000a overhaul and I am glad you checked in. I have a set of Rectilinear Mini III's I just recapped and was gonna sell them since they are 4ohm. Then I discovered the ohm switch on the back of this receiver. I'm hoping they will become best friends. By the way... I found two small oil caps on the control board. Did you replace them on yours? I'm not having much luck finding these. Anything you wish you had done on yours or would have done differently?

    I will post my list. I'm gonna order tomorrow. Any suggestions on how to make this 3000a the best it can be would be greatly appreciated!

    Thanks!

    *List disclaimer* This is my first recap and I did check this list for errors(several times) but a few may have slipped through. I will post an "as bulit" list when I am complete and have everything working.
     

    Attached Files:

  6. KlausDK

    KlausDK Active Member

    This is entirely up to you, but I guess if Sansui bothered to make a new SM for the 3000A, I would think that there is more than one cap that differs.

    Klaus
     

     

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  7. dirtman

    dirtman The Dirtman Subscriber

    Messages:
    185
    Location:
    Richmond VA
    I have already found a couple errors on the list that are limited to the control board. It seems the parts list for the 3000 are a little different from the as built 3000a. I found two differences today as I was going through it for the 10th time.

    1) C708 & C727 oil caps are 400wv as opposed to the 250v listed in the 3000 SM.
    2) C716 & C735 caps are 10uF 15wv as opposed to 30uF 15wv as listed in the SM.

    Like I said earlier, I will post a better list when I know I have it worked out. I put this one up in case someone here may have any suggestions on how to make this project better.
     
  8. kevzep

    kevzep Its all about the Music

    I did mine a few months back, I just hand wrote a list, yeah the values are strange, like 30uf but now they only do 33uf for example.
    I did the caps in the tuner section too, didnt seem to affect it at all. But I had to replace a couple of transistors in the IF section as mine had problems there with the transistors breaking down under load. Tuners in these things sound really good!!

    I have to go back and look at the driver section, I need to re-transistor it, its throwing about 2VDC from the output at the moment......:yikes:

    I will get to it one day..........
     
  9. dirtman

    dirtman The Dirtman Subscriber

    Messages:
    185
    Location:
    Richmond VA
    It's my first recap and I plan to keep it for a long time so I'm probably a little over zealous and perhaps a bit nervous I might screw it up. So far I think I'm on the right track.
    I played it steady for a couple weeks and it plays well but I have to boost the highs and lows to get it to sound the way I like, so i figure it is due. No other problems except a couple scratchy pots. I'm skipping the tuner. I rarely listen to FM cause the stations around here are garbage unless you like really loud car commercials. Besides, reception is incredible. Even without an antenna. I've been reading alot about problems with the transistors in these. I don't think I am have troubles with that yet. It cranks right up nice and doesn't distort with my bookshelf JBLs.
     
    Last edited: Sep 14, 2010
  10. Sam Cogley

    Sam Cogley Last of the Time Lords Subscriber

    Messages:
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    Location:
    SW Missouri
    I can't remember if I changed those caps out or not. I assume that I did, I probably used polys or something in their place.

    I rebuilt the MPX circuitry in my 3000A to the 3000 standard, as I couldn't find a 3000A schematic when I was working on it. The board is the same, and it seems to work fine.
     
  11. dirtman

    dirtman The Dirtman Subscriber

    Messages:
    185
    Location:
    Richmond VA
    I ordered the parts today from Digi-Key. They were a little more $ but had everything I needed and the shipping savings made up the difference. I went with all Nichicon and Panisonic for the 5 big caps. Hopefully that was the way to go. I don't have much schematic experience but I did find the same errors in the cap values listed in both the 3000 and the 3000a SM's compared to what was in the actual unit. I guess it really pays to check. I could not find replacements for the .001uF 400v axial oil caps anywhere and am gonna leave them for now.(located on the control board) I researched these and, if what I gather is correct, they control how much treble is rolled off when turning the knob. (my very low tech analysis) Not sure how big a deal it is to leave them.
     

     

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  12. larryderouin

    larryderouin Turn it UP, POP? PLLUUEEEZZZZZEE Subscriber

    Messages:
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    Like Sam said use a poly film cap in place ofthe oil in paper. Cheap and plentiful and all different brands and types. Those oil caps are literally bombs waiting to go off. SUZUKI BRAND???? DON'T WAIT!!

    You could use a radial poly film in place of the axials on the control board.
    Here's a Radial.... http://www.mouser.com/ProductDetail...EpiMZZMukHu%2bjC5l7Yfq82ymWuel20nWwaONYw%2b4=

    Here's an axial.. http://www.mouser.com/ProductDetail...GAEpiMZZMukHu%2bjC5l7YXs/SLCpfnv2km9ws5SxqDs=

    Check your control boards, pre amp and amp boards for 2sc458's(transistors). If they were still using them, they may be in there. The 258's are notorious for going noisy. Best bet is to "Shotgun them" all with 2sc2240's or equivalent. I did this with my 2000A and it became a black hole with no input. http://www.mouser.com/ProductDetail/Toshiba/2SC2240-GRFT/?qs=/sslhGPpiOR3XjNwkR44HA==

    Larry
     
  13. Sam Cogley

    Sam Cogley Last of the Time Lords Subscriber

    Messages:
    30,672
    Location:
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    It bears repeating that Sansui, for who knows what reason, folded their cap leads over and soldered them to the traces with a significant contact patch. I had to use a chisel tip on my soldering iron to pry them up just to desolder the leads. It was worth it, but a PITA to do. For the new caps, just follow the normal method.
     
  14. dirtman

    dirtman The Dirtman Subscriber

    Messages:
    185
    Location:
    Richmond VA
    Unfortunately I wouldn't know a 2sc458 if it bit me on the a$$. I googled it for an image and came up with a black "top hat" looking part. I checked all the boards and found very few that even resembled it. The ones that did were not c458's and were located on the tuner boards. Am I missing something on the 458's?

    Sam - I see all the leads tucked in tight with gobs of solder everywhere. I sure picked a challange for my first one. I've been practicing removing parts from some old boards I had kicking around so I'm feeling a little more confident. I took your advice and picked up a chisel tip today.

    Larry - I'm gonna order the .001uF caps. I need to put together a list of parts for my next victim to save on shipping. Problem is I have to decide which one to do. I have to choose between a Sherwood S-8900, Poineer SX-1000TD and a Scott 357. All three work well and are in great shape except they sound flat.

    Thanks for the help!
     
  15. dirtman

    dirtman The Dirtman Subscriber

    Messages:
    185
    Location:
    Richmond VA
    Here are a couple pics of the power board and control board.
     

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  16. nosirrah

    nosirrah Moderator Staff Member Moderator Subscriber

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    Look here....


    http://www.audiokarma.org/forums/archive/index.php/t-204378.html
     

     

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  17. dirtman

    dirtman The Dirtman Subscriber

    Messages:
    185
    Location:
    Richmond VA
    Ok. I may have jumped the gun on the 458's. I found a total of 4 of them. Three(orange ones) on the FM stereo indicator board and one(black one) on the protector board. Do they need to go? Here are pics of them.
     

    Attached Files:

  18. Sam Cogley

    Sam Cogley Last of the Time Lords Subscriber

    Messages:
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    Location:
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    I've never changed the 458s, though I did have to replace several transistors on the FM/MPX board to get it working. I'll have to think about that for the next time I have it open (my AM still doesn't work).

    Sansui's folded leads are a PITA. If you can successfully recap a 3000A, you can do anything!
     
  19. dirtman

    dirtman The Dirtman Subscriber

    Messages:
    185
    Location:
    Richmond VA
    Thanks Sam. I'm just gonna pretend I didn't read that.:D

    I'm gonna replace the 458's and hope it doesn't change anything with the tuner. That part of it is working so well I hate to mess with it. My gut feeling is that it won't.
     
  20. Sam Cogley

    Sam Cogley Last of the Time Lords Subscriber

    Messages:
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    Location:
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    If you're going to mess with the tuner at all, I'd recommend replacing the transistors in the MPX signal path and all of those caps, too. They're 41 years old, at the very least.
     

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