Trying to match NTE458 with a "real" part number - (includes Sparkleboost Vero)

[Toney]

 Well I still love my Sparkleboost.
The old Dragonfly single Jfet boost. It is still is my favorite booster after many years. That thing really does sound best with the NTE458 Jfet. You can build it with a J201 but that NTE part has the edge. Thing is, the NTE's are ridiculously overpriced like ~$8 each around here. I have looked off and on for a replacement for the NTE for some time. It just has the highly technical "it" factor in this boost. Of course, its usually the other way round. NTE parts are wide ranging general replacements for a plethora of parts and subsequently the NTE websites will match many parts to an NTE component but not the reverse.
So, I've been searching and trying to match the specs of the NTE458 with a known part. The closest I have come so far is the 2SK117 but there are a few differences; mostly the power dissipation and maximum drain current. The package and pin-out and most of the specs are right. One thing I have considered is that NTE may slightly alter their figures to keep their sources obscure. Some of the characteristics should make it reasonably simple to track down such as low Vgs off, high-ish breakdown voltage for its type and DGS style pin-out but I cant quite "nail" it. I have tried entering all the characteristics into Mouser and Digikey's parts search engines and really this 2sk117 and the 2sk772 are as close as I got. So if anyone can help reveal what this NTE458 is  when its not an NTE458 -please do!

http://www.nteinc.com/specs/400to499/pdf/nte458.pdf

http://www.datasheetcatalog.org/datasheet/toshiba/1025.pdf

                                       

                                 

[Toney]

Just realized I made that for an slightly odd shape enclosure.
This one fits nicely in a 1590B if anyone wants/needs/cares Lol/
Note: The schem call for a 1uF electro but I used a film (C2) I have left space for a large cap.

[Richard6]

I always thought that the NTE 458 was a direct replacement for a 2N5458. Have you tried that one?

[Toney]

Quick scan of the datasheet: computer says no.

NTE re-label production (often obsolete) devices.
I would love to work out what the 458 actually is. or was.

[Earthscum]

Get some mild solvent and rub off the re-print. I identify the random NTE chips I have that way... they still have the old letter indents. I have one at home I'll look at tonight.

There was also this thread: http://www.diystompboxes.com/smfforum/index.php?topic=75853.0

Found something interesting...
http://www.diystompboxes.com/smfforum/index.php?topic=51412.0

Dragonfly: The NTE458 is  DGS ...fets like the J201 are DSG
---

In the other thread I linked, someone mentioned SK30 as a candidate. Now I'm wondering if a SK117 wouldn't also do the trick? I'll plug this one on tonight and see... I don't have a SK30, but I do have J201, N5457, SK112, and some randoms. I bought my NTE458 as a 'BS170' replacement... always thought it was MOS, lol. No wonder it didn't work as good as the IRF510. 

[Toney]

Thanks Dave, that thread was me trying a couple of years ago to figure the same thing out  
I recently made another one as part of a multi boost pedal and it came up again staring at my two NTE458s and swapping in and out other Jfets. The 2sk117 looks the closest so far when comparing data sheets. I have looked at the 2sk30A and many others.
The pinout and the case style seem much like other Toshiba Jfets I have seen so I think a Japanese model could be the one.

Good idea about trying to rub off the NTE markings. I'll carefully give that a go.

[CodeMonk]

I Entered 2SK117 here :
http://nte01.nteinc.com/nte/NTExRefSemiProd.nsf/$$Search

NTE58 comes up. Among others

At Fry's Electronic stores, they have a cross reference book that also has reverse cross reference.

[Earthscum]

Derp.... I remember how this works. You plug in the NTE part number (458) and it comes up with results.

And the culprit is...
(drum roll!)

SK9460

http://www.americanmicrosemi.com/information/spec/?ss_pn=SK9460

[Earthscum]

I was actually coming to this thread to say that the SK117  sounds pretty fantabulous! I was playing with it for a while (I may have to board one of these). The one I used biased in at about 39k.

Then I tried the J201.

If you have a 2SK117 (GR, even!) use it... almost no color, just a slight bit brighter (slightest bit). Gets some really good grit going... actually found myself dialing it back so it just broke up on adventurous picks.

I think I mentioned that I tried a J201, too.

[Toney]

Well done!
I had a search for more data on the SK9460 - not so much out there.  NTE must has bought up some enormous failed order or something for the 458 part number. I cant find much info on this baby at all. Never thought to drop the NTE prefix so derp on me Lol.
  I am really happy to have this solved even if I cant really easily buy more of them as SK9460. I recently got my hands on a few SK117 so I'll be firing it up with those really soon. 

[Earthscum]

lol... since I mentioned it, I couldn't find the 458 I had, but I did find the NTE 490 that I had bought to replace it with. I scratched the paint off with my nail, could read "BS" (I already know that). I used a little Lacquer thinner (umm... not really a mild solvent, but it worked)... there it was... BS 170.