Replacement For Toshiba 2SK170/2SJ74

music soothes the savage beast
Joined 2004
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I have received some curves of "fake" 2SK170/2SJ74 from Watanabetomoaki
that he measured, comparing them to the real thing.

The interesting thing was that they looked a lot like the J113 and J176
parts...

Of course Watanabetomoaki sells the real thing.

:)

J113 and k170 have different pinout
any idea what jfet are chinese 'experts' relabeling as K170?
 
to frozenpod1 #504

Hello frozenpod1,


the datsheet from LinearSystems for the LSJ74 doesn't show a value for max. D-S-voltage. :confused:
Greets
Dirk

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to frozenpod1 #504

I run a quartett of LinearSystems LSK170 / LSJ74 complementary pairs in one

of my BA-3 poweramps (frontend) at a rail voltage of +- 34.5 volts (with a little extra heatsink - selfmde for TO-92) for 2 years now. With no problems. They run at a temperature around 35-40 C (temperature).

So they seem to be very robust / tough.
Greets
Dirk
 
What we really need here is that Eff-ing price slasher guy
who'd slash the price of the cars during the "Creature Feature" breaks.

We need the price slasher to help us regular folk so we can buy some of these
devices.

As that's not likely to happen I take solace--drinking to my
Harvey Wallbanger posters as I shudder in fear at the thought that
the "Creature of the Dark Lagoon" may infact have been reel.

Cheers
 
Many here have already published circuits which, instead of 2SK170/2SJ74, make use of JFETs readily available.
Be it 2SK209, 2SK2145, J113, ..... etc.

True that they are not direct replacements.
And they are not 1:1 comparable in performance.
But anyone can still build very nice sounding amplifiers with a limited budget.

The UDNeSS, for example, uses 4x 2SK209GR and 2x FQA9P25.
The JFET costs less than 40 cents a piece; the MOSFET less than 2 USD each.
There is no reason to complain if you do not want to pay for those unobtaniums.

But of course there are good reasons why they cost what they do.
A matter of supply and demand.


Cheers,
Patrick