2sk77b and 2sk180 new projects

[delecoy]

Rank of 2SK180

Hi Mr. Pass,

If looking to purchase 2SK180s, should we aim for a specific rank? Will it be relevant?

Thank you much,

Cody

I purchased 2SK180's from Sun-Pec.com

They delivered as promised and I'm pretty sure they are genuine, but I haven't
had the chance to play with them yet.

Datasheets360.com - Electronic Component Search | Datasheet and Supplier Information has the spec on it.

2SK77B's, I don't know where you'll find them unless you know the guy who
owns Digital Do Main. I got a few as a gift.

😎

 

[Nelson Pass]

I don't know. I haven't had enough time to investigate further,
so they "sit" on the shelf for the time being.

 

[res07njc]

In the past, some kind DIY'er posted a pic of collected SK180 curves. From what I can tell, the C and D ranks seem to be more tightly grouped with regard to curves and higher Vgs/pinch voltage (-3 to -4V range) vs. the non-graded 180's which were more sporadic or random. Relevant? Dunno... not enough experience here, other than to say non-graded 180's would probably benefit from being match paired.

 

[delecoy]

Thank you Mr. Pass!

Thank you res07njc!

I'll aim for C and D, and assume that they'll land in an interesting circuit regardless 🙂

 

[Soundhappy]

In the past, some kind DIY'er posted a pic of collected SK180 curves.

Yes was made by Jama for example. C or D are ok but X, Y, Z probably strange. More vintage series Tokin was nice as well 🙂

 

[Soundhappy]

I remember Mr. Pass at BAF2015 speak about Maxonic hi-fi company who used SIT's transistors.

http://www.src-el-main.com/maxonic/catalog_new/sd-016e.pdf

What we see is a hybrid circuits with 2SK182 ES with vacuum tubes stage inside 😀

 

[Soundhappy]

Interesting

 

[Zen Mod]

when I grow up , I wanna be nutz as Japanese amp builder

 

[res07njc]

when I grow up , I wanna be nutz as Japanese amp builder

first must have great affair with 6bm8 before reaching mountain top.

 

[Soundhappy]

when I grow up , I wanna be nutz as Japanese amp builder

Sci-fi Hi-fi Experimenters 🙂

 

[dady]

It seems completely diy.

 

[Soundhappy]

It seems completely diy.

Interesting

Maxonic use 1 tube + 3 x SIT´s for mono channel.
Yeah is point to point hand build Maxonic quality 🙂
Small board are temporizers no audio path.
Lit'z wiring with cotton 😀 Greetings

 

[Soundhappy]

It seems completely diy.

2SK77B Digital Do-Main is not the same tech
PP stage on the last photo 🙂

 

[Nelson Pass]

I've got your toys right here....

 

[Soundhappy]

Small signal SIT's

 

[Soundhappy]

I've got your toys right here....

It's Papa toys actually 😀
Do Mr. Pass play with hi-tech Korg & Noritake Nutube triodes ?
Delicious news if mix them with hockey puck´s or Pass Sit -1 transistors into one amplifier circuit.

 

[hazard500]

I bought some 2SK180 recently from diyAudio member Joshvi, in the swap meet forum. Haven't done anything with them yet as I have been busy playing with phono amps and DACs. in my mind, I have a vision of building out something like my current class A Mosfet amp

http://www.diyaudio.com/forums/solid-state/212424-balanced-class-fet-amplifier.html#post3018407

I obviously need to invert the polarity of this design, I have a stash of 2SJ74 at home so this takes care of the input stage. And I will also need a higher supply rail for the input stage - if the output is running on 20V rails I need to set the DC operating point at top of jfet at around 22-23Volts to achieve a bias of -2 or -3V on 2SK180. Which implies a voltage rail more than 30V (-30V actually). Maybe I will need to cascade the input j-fet to cope with higher voltage.

Other question is - how best to drive the gate of the 2SK180? The input capacitance is quite high, over 2,000pF IIRC. And since the device is in common source mode, there is miller effect to consider. I may need a source follower between input stage and 2SK180, and probably needs to be a reasonable current to maintain slew rate.

What other circuits are folks around here pursuing?

 

[Soundhappy]

What other circuits are folks around here pursuing?

Find this one but not tested

 

[Soundhappy]

I've got your toys right here....

http://www.nutube.us/downloads/Nutube_Datasheet_31.pdf

http://www.diyaudio.com/forums/vendors-bazaar/302238-korg-nutube-now-available-online.html

 

[Soundhappy]

@ Mr Pass and Diyers

2SK180 data sheet say is kind of higher input impedance transistor.
We know Nutube have this usual triode high impedance output.
Could we connect them togeter without buffer for example :

http://www.njr.com/semicon/PDF/MUSES8920_E.pdf

or small iron interstage impedance converter ?

Matched directly heated triodes in small package , linear with lot's of nice characteristic
and life time around 30 000 hrs. Japan high quality component.
What else ? Greetings