Successors for V-FET SONY-Yamaha-TOKIN 2SJ28, 2SJ18/2SK60, 2SJ26/2SK76 and 2SK180

[tiefbassuebertr]

Successors for V-FET SONY-Yamaha-TOKIN 2SJ28 2SK82, 2SJ18/2SK60, 2SJ26/2SK76 and 2SK180

hello,
from follow FETs, developed arround 1970 and 1978 I need for service successors from currently production with higher reliability.
I know follow types
2SK77 (Yamahas TO-3 special outline) 2SJ26/2SK76 (Yamaha various models)
2SJ28 2SK82 (from Sony's first PWM amp TA-N88), 2SJ18 2SK60 (TA-N7) and 2SK180 (Tokin)
Any sellers offer their old stock, but the risk, to get damage devices or such with to large tolerances to the actually specifications is to high for me.

Therefore I need high quality clones of this types (more better quality as the original versions)
because chinese engineers are never sleep, I think there must be any manufactures with clones of this old types.
Knows anybody more about this?
Thank you for your advices.

Concerning Yamaha and Sony V-Fet I have found any URLs about discuss and photos so as delivery sources of old stock but it seems, nobody there are with offers from new production:

http://www.diyaudio.com/forums/showthread.php?threadid=51798
http://www.diyaudio.com/forums/showthread.php?threadid=37247
http://www.diyaudio.com/forums/showthread.php?threadid=141395
http://www.diyaudio.com/forums/showthread.php?threadid=109664
http://www.diyaudio.com/forums/showthread.php?threadid=60972
http://www.diyaudio.com/forums/showthread.php?threadid=106964
http://www.diyaudio.com/forums/showthread.php?threadid=74774
photos
http://f.hatena.ne.jp/platycerus/20071020203900
http://www.geocities.jp/craft_3/Semiconductor/SONY_Transistor/SONY_TR_53.jpg
http://vfet.blog.bbiq.jp/photos/uncategorized/2009/01/22/fiicu5_q.jpg (2SJ13/2SJ18)
http://vfet.blog.bbiq.jp/photos/uncategorized/2009/01/22/2jayjefd.jpg (2SJ26/2SK76)
http://images.buyitsellit.com/306451.jpg
http://www.transparentsound.com/transistors/vintage-transistors/sale-wanted/2SK77.gif
http://vfet.blog.bbiq.jp/blog/images/2009/02/23/2sk771.jpg
http://vfet.blog.bbiq.jp/blog/cat4743994/index.html (2SK77 inside, scroll down)
http://blog-imgs-17.fc2.com/m/a/z/mazdaluce3000/118.jpg (Tokin 2SK180)
http://mazdaluce3000.blog100.fc2.com/blog-date-200706.html (Tokin 2SK180)

 

[john curl]

Good luck, but I doubt that you will find much. These devices were taken off the market because of low yield and the improvements in mosfet technology. They were great devices in their own way, but not directly compatible with bipolar or mosfets. Some military microwave devices have similar properties, but are VERY expensive.

 

[Lumba Ogir]

tiefbassuebertr,
there does not exist such thing as high quality clones. For smallest tolerances stick to original manufacturing.
Don`t give up easily and please keep us informed about your findings.
(You will need) good luck.

 

[tiefbassuebertr]

Good luck, but I doubt that you will find much. These devices were taken off the market because of low yield and the improvements in mosfet technology. They were great devices in their own way, but not directly compatible with bipolar or mosfets. Some military microwave devices have similar properties, but are VERY expensive.

A manufactur of such military microwave devices would be in the best position, this V-FETs reintroduce. Tokin or Lovoltech e. g. An other name for V-FET are "Static Induction Transistor" see about
http://nsr.mij.mrs.org/4S1/G6.41/article.pdf
What actually happened with the old wafer production equipment and documantations by Sony and NEC?

 

[Lumba Ogir]

tiefbassuebertr,
how linear are GaN transistors by your cautious estimation?

 

[tiefbassuebertr]

do you mean this transistors about
http://www.photonics.com/Content/ReadArticle.aspx?ArticleID=33765
from this manufactur, see about
http://www.triquint.com/prodserv/types/discrete_fets/
???????????

this information is completely new for me and therefore I cannot say anything about this - but best thanks for this very interesting advice

 

[homemodder]

Dont give up yet, look here, something is on the horizon.......
http://www.semisouth.com/products/uploads/DS_SJEP120R125_rev1.8.0.pdf

 

[Lumba Ogir]

tiefbassuebertr,
do you actually need something or are you just playing around (wasting your time)?

 

[h_a]

@homemodder: that's a normally OFF jfet, I really don't see much of a difference to a normal mosfet in this part. The old Sonys were large pinch-off depletion jfets (normally ON) and so a completely different animal.

Have fun, Hannes

 

[tiefbassuebertr]

Dont give up yet, look here, something is on the horizon.......
http://www.semisouth.com/products/uploads/DS_SJEP120R125_rev1.8.0.pdf

thanks for this advice

tiefbassuebertr,
do you actually need something or are you just playing around (wasting your time)?

I need a wide range of types for repair follow components:
SONY TA-N88B
http://cgi.ebay.de/Sony-TA-N-88-B_W...temQQimsxZ20090808?IMSfp=TL090808131003r15914
SONY TA-N7B
http://www.niji.or.jp/home/k-nisi/ta-n7b-h.jpg
http://www.agoraquest.com/editor/upload/2k3440d531f0.jpg
and Yamaha B1
http://i.audioscope.net/main_yamaha_b1.jpg
You can offer me unused or successor devices of this V-Fets?
If yes, please make me your offer
If no, you did right with your statement - you're wasting my time

 

[Lumba Ogir]

tiefbassuebertr,
please get it right, there are no successor devices. I would try to replace them with lateral MOSFETs.

 

[h_a]

I would try to replace them with lateral MOSFETs.

Err, you are not serious about this, right?

Have fun, Hannes

 

[Lumba Ogir]

Hannes,
what would you do?

 

[kenpeter]

Since SITransistors have Mu, might attempt replacing them with
a Triodlington arrangement of Vacuum Triode + Bipolar? Cathode
to Base, with Plate and Collector tied together.

Though it might be difficult finding a Triode that doesn't leak too
much at the grid when the plate voltage is drawn extremely low...

The idea that the triode provides tight local 1/(Mu-1) feedback
of collector voltage to the base... Thus the collector inherits the
triode's voltgage linearity.

If there is a small signal version of SIT or V-Fet (perhaps for RF?)
you might fudge some sort of a SITlington for similar inheritance
the rule of Mu to a power bipolar device...

The bipolar mentioned above, could just as well be enhancement
MOSFET, with a bleed resistor from gate to source... Its just there
to amplify current, Voltage gain linearized by the watchful eye of
Mu.

 

[h_a]

Hannes,
what would you do?

Well, either you pay the big bucks for genuine parts (not for the faint heart certainly) or you get/build yourself a new amp. IMHO it's not worth the time to rework one of these pretty complex amps for different outputs.

And even if you did, chances are that some of the tons of other transistors in that amp also die at some point

Yamaha B1:
4x 2SK77 V-FET (non-complementary)
39 FETs
113 transistors
64 diodes
7 Zener diodes

Seeing these numbers one wonders how the outputs can dominate the sound, though.

Have fun, Hannes

 

[Lumba Ogir]

Hannes,
I was not aware of the details, see a simpler design below, lateral MOSFETs can be biased conveniently (with a resistor).

 

[h_a]

Where do you have this circlotron from?

 

[Lumba Ogir]

From a Japanese site, I don`t have the link, was having minor difficulty following the description.

 

[h_a]

You sure the power supply belongs to that circuit? In the schematic V1+V4 read as 30V, but are clearly voltage doublers (60V) in the psu-schematic.

Have fun, Hannes

 

[Lumba Ogir]

It should, lying in the same folder here...