2SK389 and MPS 18

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hi to everybody.

I'm making the Aleph P1.7 right now but i'm tring to find also the parts for the next steps.
I wanna build the Aleph ONE but here is the issue:

i'm missing the 2SK389BL and i don't know where to find it for a reasonable time.

Is there any suggestion where i can find about 80-100 of it?

I don't know if i'm wrong but Nelson told on one of his thread that 2SK370 would be a good replace.


Since i'm trying ahead of time to find all the parts for the future projects, another part that i'm missing is the MPS 18 (i wanna also build the Aleph X too).

Any good replacement for this part? would it be necessary to find this exact part inn order to correctly build the ALEPH X?



Any good advice are welcome :smash: :)


Best,
Stefano.
 
yes...i heard about the lsk but it's too expencive.
The price of this is around $10 per part....waayyy tooo much for a fet.

I woud like to know if there are fet compatible that i can use as a good replacement for this part.

Nelsooonnn pleeeaaseee help!!! :bawling:

What part could we use? :confused: :whazzat:
 
Version of 389

The K389 is current source biased, with about 1mA going through each leg. The Idss rating is not so much of an issue.

You can get articles on how JFets work at the Borbely site, and there are some Siliconix application notes that explain, amongst others, biasing schemes for JFets (search the forum). They will answer those questions. Hope this helps.
 
The phono stage is/was called the Ono, not One. The Aleph 1 was a power amplifier. They're two different animals.
The 2SK389 has been discontinued, as EUVL said above. Some are still available here and there, but they are hard to find. At least here in the US, you're never able to pin people down as to whether they have the GR, BL, or VI versions. You have to buy them blindly, and hope for the best.
As I believe was also said, two 2SK170 JFETs can be hand matched to do pretty much the same job. But again, you run into the GR, BL, VI problem.
Nelson has recently said that he's buying a different part that has similar specs. I don't remember the number offhand, but it's in the front end of the F4. How easy it is to get, I have no idea. I haven't tried. I've pretty much given up on Japanese parts.

Grey
 
I'm aware of the Linear Systems parts--I was one of, if not the first person to make note of their availability on this site. I don't count them as Japanese, however, being on this side of the Pacific. I have some on hand and find them acceptable, but they do not (yet) have any P-ch complements to the N-ch devices. I have it on good authority that they are working hard towards providing the P-ch parts, but are experiencing delays of one sort or another.
Given that the Ono only requires the '389, Linear Systems is an option for those who want to build the stock circuit. I managed to track down some BL '389s and '109s a while back, so I'm okay for the time being. It took some serious effort to locate them, though.
The thing that people don't seem to acknowledge about some of the sources for Japanese parts is that they frequently list things that they don't have in stock and even if they do happen to have stock, they can't be counted on to have stock next month or the month after. For that matter, a lot of them aren't even in business the following month. I don't have the time, the money, or the patience to chase Japanese parts. It's nearly a full-time job to keep sources lined up, as the roster changes from day to day and week to week.
It makes things difficult in that I've got several things I could post here, but if the parts aren't available to everyone what good would it do? It's a conundrum.

Grey
 
GRollins said:
I'm aware of the Linear Systems parts--I was one of, if not the first person to make note of their availability on this site.

Linear Systems has been a regular advertiser in Audio Amateur and AudioXpress since time immemorial.

The LSK389 is about $7+ for a couple pieces. As time=money this is a comparatively small parts investment relative to the sweat-equity in building a pre.

You can still get 2sk170's and match for Idss. A pair is going to come close to the moral equivalent of a 2sk389.
 
Malotron said:
Here's a DIYaudio shop with 2sk170bl/2sj74bl's with 0.1mv Idss matched pairs and quads: http://www.amb.org/shop/
-Mal
Idss is measured in mA, not mV.

Read the fine print -- they match FETs which you purchase -- I would hate to purport to measure to some level of microamps and hope to stock inventory of already matched sets.

it's also helpful to know the pinch-off voltage.

Erno Borbely has the 2sk146 dual low noise JFET for sale on his webstore.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.