Nakamichi Dragon Cassette Deck

A shiny old Nakamichi Dragon showed up at my house... Purchased from eBay a couple days ago. Shipping was prompt. Unfortunately the unit wasn't quite as advertised, but the seller has been great to work with and we quickly got the discrepancies squared away without incident.

In many ways i feel as if i have been waiting 35 years for this tape deck. I'll never forget the many trips to Lyric HiFi in NY with my father to see/hear this deck (among other toys, like the Magnepan Tympani speakers). To me, this tape deck is more than just a piece of audio equipment... It represents the unattainable perfection of my childhood. Always out of reach... until now.

The Dragon was produced from 1982-1993, and is considered by many to be the pinnacle of cassette deck technology. It is certainly a TOTL (top of the line) statement deck from one of the premiere players in analogue tape. The list price in 1982 was $2,499.00, which converts to about $6,181.75 in 2017 Dollars if you assume 2.7% annual inflation. Not an inexpensive bit of gear by any measure. 

I received the deck in its original double boxing. The outer box still has the Japanese customs stickers on it. The serial numbers stamped on the box (15780) match the serial numbers on the unit. Amazing!

I have seen mention that there were about 35,000 units produced over its 11 year run, that some mechanical changes were made from time to time up until about SN 8,000, and that some electrical changes were made up until about SN 18,000. I have also heard that most of the later electrical changes had to do with parts availability, not quality... This unit's serial number should put it very close to the Dragons peak of both quality and popularity. 

The unit was a bit dirty, with some sticky stuff on the power cord and on the top of the case. Probably remnants of some long gone tape. I gave the unit a good once over, first with a Clorox wipe, and then with Endust electronic wipes... And of course some isopropyl alcohol for the "tough to clean" bits.  Most of the marks i saw when i first removed the unit from the box came off with little effort. 

After cleaning i can see that the deck is in pristine cosmetic condition. , I am only left with 2 small scuffs toward the back of the top cover, a small paint chip on the left rear edge, and some worn lettering on the front panel (monitor, power, and eject buttons). Not bad for a piece of equipment produced at least 24 years ago. If it were built in 2016 i would say its an 8/10...

With that said. 80's hifi design was pretty ugly. Why did anyone think black anodized brushed metal with bits of plastic and lots of buttons and knobs was a good idea?

Time to see what it does!

First i made sure the voltage switch was set to 120V. It was. Then i plugged it in, turned it on... Oh oh... Those are some ugly noises. 

Next i pushed the eject button, and the door unlatched but did not open. 

I took the cover off and inspected the internals. The heads and mechanical bits appear to have VERY little wear. Its is very clean, with the exception of a small amount of dust that was stuck via static to the power transformer. It appears the dust came from some dried foam that was stuffed inside of the large spring in the door opening mechanism. All of the rubber is also in surprisingly good shape, though may not be very elastic anymore. 

It also appears that there are some jelly bean green and orange caps scattered around... It is possible that this unit is affected by the dreaded orange cap disease. NOTE TO SELF. Check the caps.

Getting the door moving again was a fairly easy task, just had to contend with a bit of dried lubricant.

Still not sure what the ugly noises were, but its likely they are related to dried rubber and lubricant. 

Now time to test playback!

I didn't have any tapes in the house to test out the unit, but there is an awesome store that sells records and tapes just down the street. http://www.vinylsolutionrecords.com/. I headed over and picked up 7 tapes. One of which is new! I had no idea they are still making tapes. 

I was pleased to find that used tapes in great condition are much cheeper than used records. $6 for 3 used tapes. And $9 for 1 new tape. 

I picked up Bon Ivar 22, A Million (the new one). Tracy Chapman, Suzanne Vega, Midnight Oil, John Hiatt, and Annie Lennox. Ah, the nostalgia. 

For this first round of testing im using HiFiMan he400i headphones. They have a nominal impedance rating of 35Ohms, and  in the real world tend to test closer to 50Ohms. According to the manual, the Dragon headphone output is best suited to drive 8-150Ohms. Perfect. 

I plugged in my headphones, hit play... Nothing but the faint sound of a motor turning.  

I looked around the online forums a bit and found a few people complaining about similar issues after leaving the deck unused for long periods of time. Based on the recommendations, and my own earlier experience with the door,  i moved all the mechanical bits around using either my fingers or a qtip. It turns out the large gear to the right of the transport mechanism is responsible for raising and lowering the heads and pinch-rollers, the lubricant was dried and it was too tight for the time-weakened rubber belt to turn. Moving the gear back and forth about a dozen times was enough to get things flowing again, and from there i could use the play, stop, pause, rew, and ffwd buttons to put the internal bits through their paces.

I had to remove the small board that houses the light and photo-transistor for the tape counter in order to clean the moving bits behind it. With it out of the way it was easy to give the idler tire a good cleaning. 

This time i pressed play and... MUSIC! 

Not just music, but Tracy Chapman sounding better than she has since my wife Chris and I saw her play almost a decade ago in San Francisco.

Next Problem: During playback (with top still off) the unit started clicking a LOT. I took a look and found that the NAAC system was hitting the stop on the left (when looking from the front of the unit). Upon a bit more investigation, it seems we either have an issue with the pinch rollers or capacitors in the NAAC/Bias circuit. First step will be to clean the pinch rollers and capstans with 99% alcohol and make sure the tensioners move well through their entire range. If that doesn't solve the problem i will likely take the nuclear approach and just replace every capacitor in the deck (i cant imagine that replacing the caps with high quality modern devices would cost more than $50 and a few hours of my time - besides, its a great way to get a bit more use out of my fancy soldering station). 

After cleaning the deck, i inserted Bon Ivar... and started to EAT THE TAPE. Fortunately i caught it fast enough and no real damage was done... I went back to work on cleaning pinch rollers, capstans, heads, and dried lubricant from moving bits. Manually manipulating things to get them moving a bit smoother.

Inserted another tape, and things seem to be working fairly well. No more NAAC clicking against the stops, no more eaten tapes.

I have been listening to the same 7 tapes play in this machine all day for the last 2 days. So far - so good.

I did note that when i shut the machine off, the left capstan stops spinning after about 6 seconds, and the right stops after about 8 seconds. I initially expected to need to lubricate the bearings.. But adjusting the oil guard washers on the capstans seems to have done the trick. They both spin for about 8-9 seconds now. Of course, thoroughly cleaning them and relubricating with PTFE oil is probably not a bad idea. 

Now, while the unit is working and sounds good. The mechanicals really should be broken down, cleaned and lubricated (using a Krytox PTFE based grease and oil), the NAAC system is getting a workout, which is likely due to some drag in the tape path, the rubber bits need replacement, several of the capacitors are in questionable health, and and and. 

I contacted Willy Hermann Services in the East Bay (he is located about 45-60 min drive from me). With a little professional TLC i think this deck can actually give a good vinyl rig a run for its money.

Here is Willy's response:
Hello Shawn -

Over the years I have found that doing specific repairs is not advisable given the age of these decks.  Such service is essentially me giving the deck a clean bill of health.  When something breaks in six months you think poorly of me.  Consequently, all I do is full service which repairs any specific problems and entails removing the transport mechanism, dismantling it, cleaning out old lubricants and replacing them, replacing needy rubber parts, mechanical calibration, reassembly, electronic calibration and verification of original specifications.  After a rebuild I return the deck to you with a one year warranty - the same as when new.  Cost for a rebuild is around $700 - $750.  

Right now my wait time is around 6 months.  If you would like me to rebuild your deck I'll put your name in queue and email you a couple of weeks before I will be able to get to it.  If you still want the service at that time, I'll supply you with a service number and you can ship the deck in.  That way my backlog stays in the two to three week range.  Right now we're probably at about three months.  Thanks for your understanding.  

Please let me know if you'd like to begin this process.

Thanks

Willy

I guess i have a bit of wait, so... DIY to treat the symptoms in the meantime. It probably makes sense to have my parents ship my old CR-2A and maybe even my dad's RX-505... If memory serves, the CR-2A deck had a belt go bad in 1998 and i never got around to fixing it, its not valuable enough to have Willy repair (though i may bring it to him for alignment), so it should be a perfect project deck.

I ordered up replacement belts for the Dragon, CR-2A, and RX-505 from http://marrscommunications.com/. Might as well take care of all 3 decks while i'm at it.

With a little luck, by the time i get the deck to Willy there wont be anything left to do other than a bit of calibration.

Listening tests and comparison to PS Audio Directstream DAC / Tidal Masters, Dragonfly Red / Tidal Masters, VPI Scout with Dynavector DV20xh2 and modified PS Audio GCPH, and Technics SL-1210-M5G with modified Dynavector DV20xh and PS Audio GCPH coming once she returns from Willy Hermann.

Of course now i think i want to get my hands on a DR-1 and CR-7A. Maybe even a Revox H1, Revox B215-S, and Tandberg 3014A.

Some preliminary listening notes:
1. pitch seems accurate, with no noticeable wow-and-flutter.
2. dolby b seems to put a "haze" over the music
3. sound tends to be a bit on the "dark" side
4. i have to remember to set the deck properly for the type of tape and noise reduction every time i change tapes

Some modifications i'm considering:
1. adding heat syncs to critical transistors for better thermal stability (i have a bag of to-92 heat syncs around - so why not use them)
2. add Soundcoat gp-3 damping material to the casing to eliminate "ringing"
3. Opamp upgrades
4. Ant4066 switch upgrades
5. Signal Path capacitor upgrades
6. Power supply capacitor upgrades
7. replace lamps with LED's

Now: Back to listening. 

http://www.willyhermannservices.com/index.html

http://www.tonepublications.com/old-school/nakamichi-dragon/

https://www.nakremotes.com/Geo/Scott_Nak_FAQ.htm

http://www.angelfire.com/wi/blueswapper/bluesnak99.html

https://www.hifiengine.com/manual_library/nakamichi/dragon.shtml

https://hydrogenaud.io/index.php/topic,38024.0.html

http://mortechpr.wixsite.com/cassetteadventures/single-post/2015/09/23/The-Fabled-Nakamichi-DRAGON

http://www.ant-audio.co.uk/4066/Nakamichi_Dragon_Modification_with%20ANT4066.pdf

http://www.audiofixplus.com/modsandfixes/nakdr1.html#intro

http://www.fidelityaudio.co.uk/nakamichi-dragon-level-1-498-p.asp

http://www.tapeheads.net/showthread.php?t=22798 <- attached="" capacitors="" list="" of="" p="" this="" thread="" to="">
http://www.tapeheads.net/showthread.php?t=11095
http://marrscommunications.com/