The Pass Pub: The High-End Off Topic Thread

Now what's the name of that critter again?

Magura :)

Those are J110's. Onsemi even claims they are suited for audio purposes.

Have a look at the latest scavenging results. The Jfets on this picture were sitting in an old, top of the line, yamster preamp. If you thought the 2sj109's were rare then try to get your hands on some sk147/sj72 complementary pairs;) I beleive the 2sj90/2sk270's are pre sj109/sk389, dual fets. Any info on those would be really appreciated. Maybe Jacco, if you are watching?
 

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2sj90/2sk270's are pre sj109/sk389

Lunch comes before posting garbage.

J90/K270 are still found in early 80s gear (for instance Harman stuff as the HK870), NEC was also still manufacturing duallies in an identical package in that period.

Japanese semi manufacture tends to keep devices in production for roughly two decades, makes the Siliconix SST/U monolithic dual JFET series look downright silly.
Matched HD-Dually sets as J73/K146 and J75/K240 were manufactured in parallel with the monolithic dual jfet J90/K270.
Japanese device series production tends to overlap, but without addition of a complete new production line, so starting up manufacture of the J109/K389 likely meant shutting down the earlier monolithics.

Hey, hang on, you're ruining a perfectly good junk thread with this talk !
 
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Thanks for info guys:cool: I knew you knew something:) Its nearly impossible to find any info on those parts. Here is a little more funny stuff from the yamster (Dont worry, this is the last (I think)). Dual BJT's! The basepins are tied together at pin 3. I feel like puttin' those old components into that Kubota Takashi preamp that Babo once posted. Those dual BJT's were born for that purpose, it seems. Sure would please him, if he is watching.
 

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Official Court Jester
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Steen - that's sissy pre - currents through stages aren't good even for phono section .....

I'll draw improved schematic with one hand tied :rofl: , even if I'm toob boy .

same story as Kaneda pre , well known from ancient times ...


in fact - make it if you like wooly sound ........ :clown:

regarding 7-legged bjts - look at schematic of ZM's Silver and Manu's HK

:bawling: you can guess - both main pcbs are naked now - waiting for population per new schematic .

edit :

Babo is looking now , that's sure ;)
 

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Official Court Jester
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look at Serbian DIY-a , ther is one nice Kaneda thread .... and our funny kwayzee Juma/Sipi posted pretty nice Jfet in /folded cascode /blahblah output stage line stage amp

there is also Protel pcb file for one of variants , with somewhat lower voltage and without cascodes .

anyway - if you're making it symmetric , and with NFB - just make it susy ; there is no point in doing different .

if you're going in otherway - symmetric and wthout global NFB - make your BLowtorch (you remember megagigagizmosupoerduperblaster egotrip thread ? ) iteration

if fun is name of da game - make toob pre , and forget this sissy parts without vacuum implemented

:rofl:

( you know that I'm joking ; do what you wanna do - I just wish ya best fun )
 
Those are J110's. Onsemi even claims they are suited for audio purposes.

Have a look at the latest scavenging results. The Jfets on this picture were sitting in an old, top of the line, yamster preamp. If you thought the 2sj109's were rare then try to get your hands on some sk147/sj72 complementary pairs;) I beleive the 2sj90/2sk270's are pre sj109/sk389, dual fets. Any info on those would be really appreciated. Maybe Jacco, if you are watching?

I have some 2SK146/147 and their p-channel compadres!
Besides getting rid of them, what can I do with them? Could do a MC-stage of course... Hmmmm
 
I have some 2SK146/147 and their p-channel compadres!
Besides getting rid of them, what can I do with them? Could do a MC-stage of course... Hmmmm

They can be used as substitutes sk170/sj74. They can dissipate even more heat. R-K dont bother building anything with them, just send them to me. Thats a lot easier for you, right:D I recall looking for 2SK147's some years ago when i wanted to build Kuy-yang-wang's "El-Cheapo" with MC input. I gave up finding them, back then. He suggested 2SK369 as substitutes as far as I recall.
BTW, dont hang me if Kuy's name is misspelled;)
 
They can be used as substitutes sk170/sj74. They can dissipate even more heat. R-K dont bother building anything with them, just send them to me. Thats a lot easier for you, right:D I recall looking for 2SK147's some years ago when i wanted to build Kuy-yang-wang's "El-Cheapo" with MC input. I gave up finding them, back then. He suggested 2SK369 as substitutes as far as I recall.
BTW, dont hang me if Kuy's name is misspelled;)

Hehe. Maybe, maybe.... have had them since Ernö came up with his MC amplifiers with these, maybe 25 years ago or so. Did cost me a fortune then!

-RK
 
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Interesting top note:
Google translation. Looks like boards are available, to at least those who know what they are doing. I'm out.

Price performance of pretpojačala not small. Therefore, if something is not clear and / or can not find answers to their questions, rather it should not get involved in the project. Draft board and layout elements here are the critical success factors and I therefore releases its draft entrusted to experienced professionals. The result is high quality corrugated plates that you see here. Surplus created tiles can give to interested builders, with adequate compensation.
 
Thanks for the link. Ushkok looks pretty interesting, and should sound good with a Shunty, indeed ( I would probably delete the DC servo, and insert a good outputcap in its place) :) Yeah, that Blowtorch thread was fun and a circus at times, but after a few pages it becomes a sad story...he-he.
Tee-Bee, did you ever build ZM's LU-SUSY? I recall you wanted to, once upon a time....
 
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