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Thursday, 24 August 2017

Oddball prototype Linn LP12 power supply. The Linn Wakonda.

I'm just posting this because I'll probably never see another. Apparently there are only a slack handful in existence ...

It's a prototype Linn LP12 power supply. Apparently called a Wakonda, it's a bit like a bastard son of a lingo and an axis (of evil), with a hole in it!


It's a pukka job. Obviously some sort of prototype...


It's obviously had some use as the board has discoloured from heat underneath the droppers, and, as usual, a re-cap restored operation ..... except 45 RPM....

... which was traced to two missing pull down resistors, not catered for on the board, and never fitted... perhaps the previous owner didn't have any 45's ??!

One interesting feature is the output transistors are bonded to the heatsink with some sort of cement. The digital phase generator is almost identical to a lingo, and allows LP12 users to switch between speeds without all that tedious mucking about with the belt.

Here's some photo's of it's final resting place






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12 comments:

  1. Andy Goloskof26 August 2017 at 17:25

    Fascinating, thank you for sharing. I always associate droppers either as cost cutting or bad design. Linn???? So close to the electrolytics as well... Hmm. Still damned interesting though!

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  2. Unknown12 September 2017 at 20:24

    Hi Andy,
    I have just purchased a Mitsubishi MC8000 and hoping to get it all working again - I have read your blog entry from 2016 when you fixed a unit (didn't sound too much fun).

    A quick question before I get working on the unit - i see that there are a few places to buy replacement belts, but I can't find too much on replacing the bulbs that control the record player arm - can you recommend a website that will help me buy replacement bulbs?

    Many thanks - Gary

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    Replies
    1. Doz13 September 2017 at 10:01

      Hi Gary. Whereabouts on the planet are you?

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    2. Unknown14 September 2017 at 06:26

      Hi Andy - I am in Salisbury, UK

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    3. Doz14 September 2017 at 13:08

      Measure the belt, and order the nearest size from cpc.co.uk
      The bulbs you can replace with a common yellow LED, with a 470 ohm resistor in series.

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    4. Doz14 September 2017 at 13:15

      I *think* (can't be 100% sure) that this is the tt belt. http://www.ebay.co.uk/itm/TURNTABLE-DRIVE-BELT-FRX21-FRX24-5-diameter-170mm-200mm-5mm-Wide-/221579213723?hash=item3397267b9b

      Delete
  3. Unknown14 September 2017 at 17:57

    Hi Andy,

    Thank you! I must admit I am not really an expert on electronics, so I will start taking it to pieces over the weekend and see if I can establish what is blown or broken.

    I checked eBay via your link and found a Germany company that supplies all belts required, so I have ordered those (just so that I can renew them all).

    I know that the light that shines down over the centre of the record is not working - is that one just for show, or does it fulfill a function?

    Many thanks - it's just good to have someone to check with as I go.

    Gary

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  4. Unknown15 September 2017 at 07:53

    Excellent- thank you Andy 😀

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    Replies
    1. Doz18 September 2017 at 23:26

      Gary, If you need anymore help, just post up on the relevant post. Helps keep things tidy ;)

      http://andydoz.blogspot.co.uk/2016/06/mitsubish-mc8000-audio-system-repairs.html

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    2. Lilli26 March 2021 at 13:39

      Doz, I think I have one of these Linn Sondek Wakonda prototype decks. Got it from a guy in Scotland in the late 1990’s that used to work for Linn. He said it was a prototype and I seem to remember him saying there were only 3 made but I don’t know how true that is. It has worked but now I need it fixed ;)

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    3. Doz29 March 2021 at 13:10

      I heard a similar rumour. I know of four now...

      Delete
  5. Anonymous16 March 2024 at 07:13

    hi . i know it was almost 7 years when posted but would like to know about the pull down resistors on the linn psu wakonda board . if you could show the position in a photo that would be so i can check to see if they are on the board so it can play 45s . thanks .

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