DIY progress report

GRollins said:
I suspect that the 2SK170 and 2SJ74 are actually discontinued, production-wise and that Toshiba only continues to list the datasheets in order to support product that is in the distribution pipeline.

It was possible to get 3SK389's and 109's for quite a while after
they were discontinued, but that seems to have finally dried up.

I am told that Toshiba will be releasing updated versions in the
future.

As to 170's and 74's, we are currently buying large quantities
of 2SK370 and 2SJ108, readily available from Toshiba. These
are easily matched to give equivalents to 2SK389 and 2SJ109.

😎
 
GRollins said:
I suspect that the 2SK170 and 2SJ74 are actually discontinued, production-wise and that Toshiba only continues to list the datasheets in order to support product that is in the distribution pipeline.

It was possible to get 3SK389's and 109's for quite a while after
they were discontinued, but that seems to have finally dried up.

I am told that Toshiba will be releasing updated versions in the
future.

As to 170's and 74's, we are currently buying large quantities
of 2SK370 and 2SJ108, readily available from Toshiba. These
are easily matched to give equivalents to 2SK389 and 2SJ109.

😎
 
> I am told that Toshiba will be releasing updated versions in the
future.

That is great news for everyone.

> As to 170's and 74's, we are currently buying large quantities
of 2SK370 and 2SJ108, readily available from Toshiba.

They look identical to K170/J74 from the datasheet, other than package (to save a bit of encapsulation epoxy).

In Japan, they have the same retail price as K170/J74.


Patrick
 
I have been lucky to buy 300 units of 2SK170GR...

The only problem is, I can´t find the time to match them...

So if anyone has the possibility to tightly match them, I´d be happy to share most of what I have... I only need 14 sets of quads.

Cheers

Chris
 
mach.88 said:
I have been lucky to buy 300 units of 2SK170GR...

The only problem is, I can´t find the time to match them...

So if anyone has the possibility to tightly match them, I´d be happy to share most of what I have... I only need 14 sets of quads.

Cheers

Chris


I presume that it will be impractical sending these to Serbia for matching 😉
but-if you are desperate........don't hesitate....
 
Well, I'm off to Sea Ranch for 4 days, interviewing a building
contractor (maybe I'll bump into Linkwitz) 😎.

That's not the good news.

Here's the good news:

I have decided that First Watt doesn't have any reason to wait
on publishing the schematics and layout of new product. When
I get time, any gaps in service manuals will be filled accordingly.

Of immediate import, the F4 development is finished and the
amplifier is going into production next week. The owner's
manual has been combined with the service manual, and will
be posted next week. It includes schematics, specs, and PCB
layout.

The design is an impedance converter, a no-feedback follower
that goes to 100 watts.

If you follow this thread, you heard it here first.

:cheers: