Won this one off eBay for $375 AS-IS. This one in very poor condition, but fortunately do have spare parts units. Going to convert back to a home deck and change the front panel and cover and add back the feets, also transport is going to get a full rebuilt, realigned and new capacotors and upgrade the CMOS switches.

This is the deck before restoration

When you say covert back, was this installed in a studio or similar? A great project. Is the main mech OK? (Just thinking about the NAAC etc)

Donor unit going to be this one below

Transport is still in good shape minus the dust, heads show no wear, no cracked parts, pinch roller still good. But soon enough find out if their any wear and how bad once transport is torn down.  

Don't think it was use in a studio setup  due to it wasn't modded, as far as din jack and electronics, someone must have use it in a home setup and more likely rack mounted it. Plus heads show no wear.

The one use in a studio would have this jack and mods and cmos switches upgraded already, plus they usually mod the NAAC system for a more narrow path and usually remove the metal tape pressure pad lifter over the playback head. Which this deck hasn't had any mods done except case.

Here a example of one that been used in a studio setup below 

Blimey, you sure know your Naks buddy. More than me. Out of respect I feel I should change my user name

Remove the tape transport for rebuilt, you need to have it completely out of deck

Tools needed for alignment, when rebuilting transport, as it not as easy as just spooling idler tire, cam belt and counter belt and autostop lamps and replacing capacitors. You need to remove any hardened lubricant and relube with synthetic lubricant and flush bearing of old oil, which requires dismantling of whole transport.  After finish you need to realign tape path guildes, head height and head tilt and zenith and stroke.

You are going to need four, full track alignment tapes prefer, 3khz, 15khz, 1khz for tranport alignment and 400hz for dobly level, using ones recorded from Otari reel to reel and is recorded OFF SHELL using an Otari 0.15" (3.81mm) using BASF tape stock with no inner sheet, You also going to need a WHS-300 gauge, you can buy from willy hermann for a reasonable price, or factory gauges for adjusting path guildes height, head tilt and stroke, plus basic head height, you need test tone tape to get accurate and you will need etheir a true RMS meter, or VTVM, or oscilliscope.     

One that I see alot of techs make this mistake, as they think it reference, so I have to say it. Never use Sony Super Metal Master Reference Audio Cassette Tape, to make test tone tapes or alignment, you will take a chance and wreck the heads, use TDK, or BASF tape stock only!!   

Here transport being taken apart.

Replaced Ider tire, remove all parts and clean reoil and relubed, including capstan bearings.

Here after backend of the transport back togetheir, used lock tight to keep lock washer on coil in place. Make sure when you reinstall capstan bearing back into deck, smaller one goes toward the cam, as both capstans are not the same.

Then put some oil into the back bearing of the capston and install flywheel/motor, then put a drop of oil into front bearing and reinstall front washer and clear washer seal, also you want to relube back white plastic capstan plate bearing

that is top draw retrodos , you seem to go about your work with ease you know your stuff .  i bought a 582 last week the only trouble i had was the cassette door would not open the  outer cable holder was cracked easy fix though works a treat and no cap issues on record .

Agree with Del here, A1 effort, and no doubt A1 result

You're a dying breed RD. The care and precision you take on take down/ rebuild is a a testament to the old school repair. Keep the photo journal commin'...you got an audience for this masterpiece!

I agree with all of the above, excellent work retrodos.

Start working on the head block assy and also replaced both pinch rollers, as they were no longer rubber. You do have to remove the whole guide assy due to the old lubrication dry up causing the pinch rollers to lockup and not hit the capstan. You need the whs-300 gauge to set guide height, if you don't set right, tape will be eated.

Here alignment of the guides, I also use a mirror tape as you can see path to double check.

Atfer doing alignment as far as head tilt, stroke and guides, also check back tension

Replaced both autostop/reel lamps with T1 60ma bulbs.

You want to clean the contacts for the NAAC variable resistor potentiometer, with contact cleaner, or take it apart

 Transport is rebuilt and ready to go back into deck.

wow, that's a project.

inside is more difficult than a revox deck.

those blue caps, 2nd photo above my reply, don't they need to be replaced?

They test good on the ESR meter, but they are going to be replaced, already order some Pansonic low ESR caps, with higher voltage rating,  and the PSU caps are also going to be replaced. Already had to replaced the voltage regulators on the PSU due to won't power on, but now works.

Recapped most the DD motor board, stil have to change a couple but have to order. The big 470uf 10v going to be change to a 470uf 25v capacitor when I receive it.

Transport back into deck, did speed adjustment, which measure 3khz on counter, head height and azumith alignment. Works great. Next will be to recap and upgrade electronics, which will be in a couple weeks, as have to wait for cmos switches, capacitors to arrive.

Here a couple videos of the deck working, bought back from the dead, as it didn't even power on before.

wow,

i wish, i could repair vintage equipment

breathtaking job retrodos, master resurrector of tape decks in suspended animation 

master at work

To see the legendary Dragon reborn....priceless. Excellent work RD!!!!

a.k.a. the Nakamichi Phoenix

from the ashes!!

Excuse me, but I can't believe that. To play a tape with test tones or to align head is EXACTLY the same job for the deck as it would be playing music.

So if you are stating that that superb tape (like the SONY Metal Master or any other excellent tape) can wreck the heads, then it can wreck them whether you are playing music or simple test tones, right?

I'm sorry but that sounds to me like an absolutely wrong idea, because the magnetic tape is EXACTLY the same whether has music or test tones inside, so the wear in the heads is the same.

I'm not a technician at all, but logical thinking tells me that.

I record my alignment tapes using a Otari reel to reel and is recorded OFF SHELL using an Otari 0.15" (3.81mm) using BASF type 2 (chrome) tape stock then take out the inner sheet, it's more accurate, plus it recorded in full track, recording on another machine is a bad idea as the shell affect the way the tape move, plus not good to use another tape deck as reference and you then get stereo track when factory alignment tapes are recorded in full track.    

As far as the Sony Metal Master tape, I knew someone was going to come along and disagree, but actually seen it destroy and even chip heads on NAK's overtime. I always use to say, "metal tape is one way of destroying a Nak head", because NAK head would almost last forever.  Wear on the head is just alot more. Plus the reason why it also sure never be use for aligning heads is due to the same reason as the weight affect the way it move across the tape path, which is not good during alignment. Type 2 (chrome) better for this, plus many type II tapes had signal-to-noise ratios equal to or better than metal tapes simply because metal tapes were so noisy, but metal type IV had the most accurate housing available. But one of the other disadvantage is they remained way too expensive to be bought in bulk.  

I can understand why some people like Sony Metal Master tape for the sound energy, better high frequency. Best tape to use is TDK SA or SAX, or BASF type II.

Your know when you heads are getting worn when their alot of high roll off on tape, and it get's worser and worser and sound gets duller and duller.

http://tapetardis.wordpress.co...etal-audio-cassette/

Yes it will wear down the heads etheir way. But one other reason for never using it for tape alignment, as weight of tape and shell, affect the way it move across the tape path. Reason why I only use custom BASF type II tape, or TDK stock, not because of sound, their alot more that goes into make a good reference alignment tape.   

I'm sorry but I disagree, retrodos. I searched for some info about that and found that many people says the opposite, i.e. at Audiokarma, Audiogon or Tapeheads.net. I cannot believe that the best and expensive tapes are the worst. It has no sense to me.

Many audiophile are saying that the worst chrome tapes are the pure chrome formulation: Basf, AGFA, etc, and not the alternatives used by TDK, for example, which are of much higher quality than the first ones. This is also confirmed by very thorough and precise audio tests made by respected magazines like AUDIO magazine (see supertests made at 1990 or 1993).

The worst tapes and those that causes real wear to the head (not wreck, as this is impossible) are both the cheapest ones, and pure chrome formulation. Many people talk about the 'Metal urban legend', saying that it's completely false. One example is, the founder of Pacific Stereo, that has been official service of Yamaha, JVC and many other brands and it's also PCB designer, so he's not exactly a 'sucker'...

Let's see if any other member can give some info about this.

BTW: why don't you show the autoreverse function of the deck in the video? The autoreverse is the most special feature of the dragon...

Pure chrome stock was not a "cheap way", or "worst way" at all for the music industry at all. They paid a premium for chrome and objected at the higher cost. TDK tape was very inconsistent, but that may have been because their coating facilities were making running changes to try to match BASF stock. When a single pancake is 4 miles long and you run them 24 hours a day, every day of the week, you quickly get a good idea of tape consistency and quality. Consumers preferred TDK SA. Engineers and technicians preferred BASF pure chrome, but their a few other master technicians, that also use BASF only. 

BASF made all Type II reference tapes, despite what TDK claimed in its misleading advertising. These tapes used either DuPont's invention of chromium dioxide (manufactured only by DuPont of BASF because of the enormous expense in heat/pressure reactors required to form the particle) or ferric oxides enhanced by the addition of magnetic cobalt to the crystal structure. Chrome was the first Type II tape, but Sony's exclusive distribution deal with DuPont forced other Japanese tape manufacturers to find an alternative in ferric-cobalt (an Agfa-Gevaert invention that they were never able to stabilize properly until the Japanese figured how to do it.) Chrome had the lowest noise because of its perfect particle size and near perfect uniformity that allowed easy distribution.

Took info From someone that posted the companies internal documents a while ago.

DIN Type II Reference Tape C 401 R BASF 100% pure chrome IEC Type II Reference Tape S 4592A BASF 100% pure chrome IEC Type II Reference Tape U 564 W (replaced S 4592 A in October, 1987, in the IEC meeting in Prague)
Magnetic Media Information Services, Volume XIII, No. 5 (August 20, 1993) discusses the technical work of Dr. Manfred Ohlinger, BASF's chief of pigment development. Dr. Ohlinger discussed work on CK60/XH, a chrome pigment with a coercivity beyond 1000 oersteds. He had already produce CK/75/230X with a value of 900 oe. and CK57/200X with a value of 670 oe. BASF was in full development of advanced pure chrome pigments for new 3480 cartridges and other media.
BASF had been producing pure chromium dioxide pigments in a huge reactor in Ludwigshaven, Germany, since the late 1960s. In 1995 the oxide lineup included: CK 40-14 for audio tape CN 43-11 for high performance, single-coat audio tapes CK 37-11 for the lower coating of high performance chrome audio tapes. This pigment was designed for non-cross-linked binders. CK 48-21 was for the upper layer in cross-linked dispersions. These oxides were used in Chrome Super and Chrome Maxima tapes. The tapes were identical and differed only in the housing and the tighter specs for Chrome Maxima. Most Chrome Super performed exactly the same as Chrome Maxima.
CK 50-21 was pure chrome used in VHS, S-VHS, TMD, and DCC formulations. (BASF made the only DCC tape. It was the tape in TDK and every other DCC cassette made.)
There were CC variations of these pigments. They differed in that oxygen molecules were attached to the crystal surface to prevent degradation to hexavalent chrome in the presence of water.
BASF used 100% pure chrome formulations for its EE reel-to-reel tape and for Loop Bin Master 920 and 921 used in the duplication industry before digital bins arrived. The only "hybrid" chrome/cobalt audio formulations appeared with the introduction in 1993/94 of "Chrome Plus" duplicator tape that had a small percentage of cobalt-ferric pigment added to raise AT315/MOL315. Its AT315 was 2-3 dB better than competing chrome tapes. Chrome Plus was also used in Chrome Extra audio cassettes from that point forward.
In 1992 world-wide production of magnetic powder by weight was 11% for chromium dioxide, 55% for co-fe, 32% for standard ferric, and 2% for metal powder. This total includes all applications: audio, video, computer data.
In 1994 BASF used a high-performance plastic that could withstand 95 degrees C. (203 degrees F.) without deformation. This plastic was used in the sonically welded Reference Maxima series. The tape was BASF ferric-cobalt because the heat resistance of the plastic would be wasted on a tape that had a much lower Curie point. (It was chrome's low Curie point that made it the only choice for thermal duplication--TMD--that was used for high-speed video tape duplication.) BASF kept Chrome Maxima and Chrome Super in the cassette lineup as 100% pure chromium dioxide tapes and the 85/15 Chrome Extra as its first and only hybrid chrome audio tape.

Never said Metal tape is bad quailty, tests and soundwise they are great? They generally have the highest MOL and SOL values, but also the highest noise, so in practice they exceed Type II tapes only in low print and better high frequency dynamic range. But it does put wear on heads overtime, more then others types would normally. I rack over 150 dragons, ZX-9's and tascam decks over the years and seen what different tape stock, does to the heads. Plus the Sony Super Metal Master tape is not worth the $50-$120 that they go for now each on eBay, to just record. 

And yes I am a engineer to, do product designing to. Despite what I said about TDK, is now mostly what I use, TDK SA, or Optima 4, or Maxell XLII-S, or MX-S, or MV, as I have boxes of this stuff, as bought over the years and some for cheap in a lot sale. Only have a couple Sony Super Metal Master tape for collection, as they are way to expensive to buy. BASF only use one in a while for alignments tapes, as don't have that many lefted for recording. 

Not trying to be harsh, or even argue, but never go by what most audiophilles say, as most don't know any better, or go by what paided magazines say and yes they get paided off for the most part, even the well respected ones. 

Sure start a whole another thread about tape stock.

hi, read your posts about bringing a dragon back to life. very good work.

well, i have a dragon it was rarely used in virtually mint condition except

something went wrong with mechanism and it won't play in one direction or maybe now 

it just won't play at all. it is probably a gear or a belt or something.

i am offering it for sale. are you interested? is there something i could do or check

that could give you some indication of what the problem is?

i would want a reasonable price since if it was fixable this unit would go for $1000

easily on e-bay.

let's make a deal.

awaiting your response

Just wondered which CMOS switches you used in the end, and whether you considered the ANT4066A from Alex Nitkin?

http://www.ant-audio.co.uk/406...66_datasheet_1_1.pdf