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
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!
ReplyDeleteHi Andy,
ReplyDeleteI 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
Hi Gary. Whereabouts on the planet are you?
DeleteHi Andy - I am in Salisbury, UK
DeleteMeasure the belt, and order the nearest size from cpc.co.uk
DeleteThe bulbs you can replace with a common yellow LED, with a 470 ohm resistor in series.
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
DeleteHi Andy,
ReplyDeleteThank 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
Excellent- thank you Andy 😀
ReplyDeleteGary, If you need anymore help, just post up on the relevant post. Helps keep things tidy ;)
Deletehttp://andydoz.blogspot.co.uk/2016/06/mitsubish-mc8000-audio-system-repairs.html
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 ;)
DeleteI heard a similar rumour. I know of four now...
Deletehi . 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 .
ReplyDelete