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-   -   Nakamichi statis (http://www.diyaudio.com/forums/pass-labs/79544-nakamichi-statis.html)

kyrochan 14th May 2006 11:19 AM

Nakamichi statis
 
Hallo, I read somewhere that the stasis serie of Nakamichi were designed by Nelson himself...
Is it completly true? I'm asking that, because I need a new tuner and I've found the following item on internet and from "next door" sellers:
Kenwood KT-400 (but no-one knows anything abpout this model)
Technics st-s1 (a 190$ model from 1980)
a newer Kenwood model (quartz locked, it also come from 1980, but I don't remind the name, this is a photo link: http://i15.ebayimg.com/04/i/07/19/11/24_1_b.JPG )
a Sansui t-60
and a Nakamichi sr-3a,
in some review I read that it has a weaked tuner
...but it has an headphone output and I love this thing!
(surely, ..if it is not a merely crancky opamped one...)
Can any one help me to choose one of these???
Cheers,
Domenico

cjd 15th May 2006 02:41 PM

Far as I know, Mr. Pass did indeed contribute the Stasis circuitry used by Nakamichi.

I have a TA2A myself and it's very good sound, though lately I have a component that is constantly building new solder bridges and introducing a nifty buzz in one channel (not to mention throwing the balance).

C

jacco vermeulen 15th May 2006 04:19 PM

I think NP posted years ago something in the line that it was a money deal. Also that though the design of the power amplifier was basically that of the Threshold S-model, the components, layout and construction used were all Japanese.
I've heard both the Nakamichi 5A and the 7A Stasis power amplifiers when they were on the shelfs, definitely not the same as a Threshold amplifier.
Interesting that topology can be identical, and there can be such a big difference.
Mind you, in those days i was seriously thinking of getting a Nak, viewing that it was the only Pass amp i could afford with great difficulty. (and an ocassion at that)
I thought the receiver was just a license deal.
Would be nice if the Great Evil One himself has some additional bits of the Nakamichi Stasis story for history preservation sake.

Nelson Pass 15th May 2006 08:37 PM

It's pretty much as you described it. Jacco. Big $$ for little
signature.

:cool:

anatech 16th May 2006 06:13 PM

From what I saw servicing the PA-7 and 5 amplifiers, they sounded very good. They were extremely reliable as well. The input circuit was totally different to the Threshold designs. I'm not surprised it sounds different. I wouldn't mind having one (Nakamichi).

Quote:

I have a TA2A myself and it's very good sound, though lately I have a component that is constantly building new solder bridges and introducing a nifty buzz in one channel
I have a TA-2 as well. Great sounding little set. Does not like low impedance loads in that it affects the sound quality. There is an under rated resistor that feeds the current source circuit. One per channel. It opens up over time. Replace it with a higher power rating metal oxide resistor. I can't remember the value off hand right now.

-Chris

cjd 16th May 2006 07:30 PM

Wait...

you say it sounds bad on low impedance loads?

Ooh boy, I can't wait to get my X-GC finalized, 'cause my mains hit 2.8ohm and they already sound excellent with the TA-2A, so I really wonder what their potential is (one other has built 'em - actually picked the drivers and had me do crossover and I ended up building 'em too - and they've picked up rave reviews from his visitors)
. ;) And the Nak is the only amp in the house that handles it. The buzz issue has existed far longer though.
The problem item (or, where the bridge forms) is between two legs of a TO-220 case so not a resistor - I'll see if I can find a toasted R though.

anatech 16th May 2006 07:42 PM

Hi cjd,
The little Nak TA-2 will dump a lot of current for it's size. A little better than a Marantz integrated it seems. Because it doesn't have a lot of paralleled outputs, the sonic performance into low impedance loads suffers. The PA series is much more forgiving that way.

Don't forget, the feedback is taken before the output transistors, so they are running open loop. The non-linearities are not corrected for and they are a larger magnitude than in a multi-output situation. There, the change in current is spread out over many transistors.

I am trying to visualize the problem you are having with "bridges" on the PCB. The solder should not be hot enough to flow. Picture?

-Chris

cjd 16th May 2006 08:15 PM

I already removed the old solder and re-soldered but there is a fair amount of solder bulk at the pins (I wish I knew what actual device it was - heatsinked, TO-220 package [could be larger actually - is that TO-5? don't remember]) since it sort-of "floats" into place. This solder is bridging along a path between two of the pins.

If it is indeed happening yet again I'll see if I can snap a pic. I'm more sure that it's happening again than I am sure I can get a pic that's clear of something that small. ;)

C

anatech 16th May 2006 08:33 PM

Hi cjd,
Odd. Never have seen anything like what you describe. Poor previous service?

-Chris

cjd 16th May 2006 08:49 PM

Far as I know this unit sat in a cabinet (in use - mind, it was cramped so had poor cooling) at my grandparents place for its first many years of life and was never serviced. It also has only one channel of the phono input working. I've had it for only about ten years now (wow, has it been that long?!)

And, maybe "whisker" is a better term to be using - it just grows enough to bridge eventually.

C


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