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Green Wagon

Nakamichi RE-2 - This time it's personal.......

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Next on the bench is my own personal closet baby. Admit it, we ALL have at least one of these..

 

This is the first piece of home audio I bought brand new, with its companion the 4MBs 7 disc changer.

Oh the joy of not having to swap CD's every 45 minutes...

 

I bought them new in around 1988, so that makes them 27 years old.

 

Previously (2004) I have replaced;

The memory battery, More as a preventative measure to stop any issues with battery leakage.

Re-soldered the board, Again preventative.

Better binding posts, This meant relocating the board that was soldered to the back of the posts to a nice empty spot where all the video parts are located on the RE-3. (Next model up that has video switching)

Moved pre-driver transistors, Partially preventative. As you'll see in the pics, in the original board location the board had already gotten to hot for long term reliability.

 

The surprising thing is, even at this age, and having spent most of its later life in a cupboard, every time I pull it out and use it, it works flawlessly.

Well, that is except for the speaker relay, its slowly developed a little hesitance to close the contacts cleanly.

I'm also somewhat surprised that not one single cap (all original) is showing any signs of leakage.

 

This time round, I'm giving it the love it deserves.

 

Full re-cap with premium (expensive) caps. Most likely Panasonic FR's and possible replacement of some electrolytics with films.

The two main filter caps are going to be an absolute nightmare to find replacements for due to their low hight.

Better still binding posts.

New battery (again preventative).

Redo pre-driver 'heatsink' with something a little more 'professional' looking. :D

 

These pics are how it sits today.

Once I've completed the work I shall update this thread with new post work pics.

 

I'm dead sexy.

 

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Even more so when I'm turned on.

 

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Yeah my bum isn't that exciting, but i can split my pre out from my amp in.. Rather a nice feature.

 

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Not the prettiest interior, but I've seen way worse.

I also moved the smaller mains board when I replaced the useless 2 pin UK style output socket with a 3 pin IEC socket.

 

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Two story internals.

 

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Ouch, burnies. When I noticed this I moved to the separate pre-driver heatsink and rebuilt that area with new metal films etc.

 

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On so nice to have removable base plates.

 

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Yes, even my own gear looks like its been hit with TNT while under the knife. Seriously it's the only sensible way to work on 90% of the electronics made.

 

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Don't expect an update any time soon. This is gunna take a while due to fabbing a new heatsink and speaker posts and plate.

 

It takes time to open the unit, do a build list of needed parts, trawl the suppliers sites to find suitable replacements (It can take a day or longer to find some parts).

Then theres waiting for parts to arrive. Assuming they even have what they say they do <_<

Next is swapping in the new parts, Making the mounting plates or adapters as needed.

Finally, all going well, reassembly of the internals, testing, realigning, cleaning, reassembly of the case work and cleaning of that as well.

 

It all takes time. Some of that time repairers will never see a cent for.

Remind me again why we do this ????????????????

 

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A credit to you @@Green Wagon,

For hanging on such desirable Japanese gear and having it presented in the condition it's in all those years. Its typical Japanese built quality especially from the 80s.

I use to dream of owning a high calibre Nakamichi System. The closes I got as a teenager was a Nakamichi Bx-1!

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Ta.

It's just a shame that under HK's ownership they turned to, quite frankly, Poo.

 

To my mind it is one of the best sounding receivers of that vintage.

Others may have their love of sansui/nad/rotel/luxman/etc.

I'd happily put this against them (to win) without any hesitation.

 

Plus I always had a soft spot for the angular 'stick out' buttons.

It's, 'quirky' ? small bits of styling that get me in..

 

Early alpine car audio gear, MF X series, and so on.

 

~2 hrs of solid searching and research, checking pdf's etc, I have found the hardest item. The main filter caps.

 

Originals are Elnas, 85 deg. 6,800uf 63v

2,000hr - 0.037esr - 4.6amp ripple.

absolute maximum of 36mm diameter and 45mm high.

 

New ones will be Rifa's, 105deg. 6,800uf 63v EDIT, And their $20 each...........

6,000hr - 0.03esr - 4.5amp ripple.

35mm diameter 45mm high (really tight squeeze).

 

Marginally better ratings, but much better life span and temp.

Mind you, where they are temperature is not an issue.

 

EDIT; Parts ordered. Ouch. $230 not including the speaker posts or the 'new' heatsink for the pre-drivers.

And some of those parts are ex usa/uk. So like I said earlier. Parts can delay work by weeks.......

Oh well. Once done it should be a very happy beasty for another 25 years........

Edited by Green Wagon

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Never know what might happen...

It's sitting on the 'waiting' shelf while I work on another luxman. But thats for another post in a few weeks. It'll be a huge post as this one is something really special. Well I think so anyway..

 

In Nak land... all audio coupling caps have (or will be) replaced with mkp's. Almost all other caps are panasonic FR's

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Guest Sime

There's a Nakamichi Dragon Tape Deck sitting in Miranda HiFi for years, I enquire about it if I actually had something to play in it.

Edited by Sime

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Dragons are really nice, But good luck finding someone that has the jigs and experience needed to work on them. I won't touch a lot of nak decks as they really do need special attention.

And at this age, they'll need rollers etc that I'm not sure are available anymore.

 

 

Mmmmmmm finally.

 

My baby is sitting there warming up, waiting to be rebiased..

It's had to sit patiently on the shelf until I got the surge of repairs done.

 

Old terminals and plate comes out, New terminals and plate goes in. I much happier with these new terminals. Much neater. And I'm sure they'll make a world of difference to the sound *rolls eyes*.

 

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New brackets for second heatsink.

 

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Brackets installed.

You can also see 4 of the 6 PP caps (redish brown, upper middle of pic) that now reside where electrolytic's used to be in the signal path.

 

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New aluminum angle with new power transistors (local voltage regulators) installed.

 

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All wired up, Just need to do a little cable tidy.

 

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And this, finally, really is the end of this job :)

 

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Right at this second I don't know how it sounds.

Even if I did, it would be meaningless as it's been months under the knife, and years since I last used it.

 

The really stupid thing is, I might used it for a week or two, then, it will go back into the cupboard, sad and unseen for years more.

Maybe one day I will have a place for it to come out and either be displayed or used.

Honestly, I'm not holding my breath.

 

 

 

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Random snaps..

 

 

Old and New secondary heatsink.

 

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Old and New bigger bridge rectifier - Did this to make sure it didn't die from any extra surge due to new filter caps.

 

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New filter caps. Minor physical size difference.

 

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They only just fit the board, and just scrape in under the lid.

Don't panic. The bit of black goo is a touch of silicon I added to help stop them from vibrating.

 

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Old terminals coming out.

 

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I was hoping to edit the old post, but too far gone, so heres the final chapter in this story.

 

I replaced the memory back up battery (cr2450rv), a 3v non rechargeable lithium manganese dioxide button cell as part of the update.

I noticed it wasn't holding memory for more than a day, when the old battery was still good after ? 10 years.

I ordered a pair of replacements from a different supplier.

2 months later they hadn't shown up, so I canceled the order and went for a different cell.

A half AA with leads. Bigger than I wanted, but it would have to do.

 

I did a current draw of the new battery in system and it started at 6ma but rapidly dropped and kept dropping.

Obviously doing a mini charge through the circuit.

New fresh terminal voltage was 3.22v.

First minute in circuit it dropped to 3.19v.

Left over night, it settled back to 3.22v and all memories have been retained.

 

Obviously the so called new cr2450 was very old shelf stock or badly made.

Whatever the reason, this battery should last till it leaks..........

 

Obligatory pic :)

 

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Sad part is, as I said before, It's back in it's plastic bag safely stored in the cupboard.

Maybe it's one of those things that will be disposed of at an old mans estate clearance............

 

 

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Hello Gents.  I have a Naki RE-2 that will not power on.  Internal fuses ok.  I checked the primary side of the power supply transformer and she looks like an open circuit.  I'm no expert, but transformers shouldn't look like an open circuit unless an internal fuse is blown or major winding damage, right?  I have a spare transformer and would like to install, but need to know if there is something else I should test before installing the new transformer.  

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