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-   -   Fairchild interest alternatives (http://www.diyaudio.com/forums/pass-labs/210294-fairchild-interest-alternatives.html)

buzzforb 7th April 2012 02:53 PM

Fairchild interest alternatives
 
I am going to open this up to discuss alternatives to the N channel parts spec'd in the the F5T. The P cahnnel parts can still be had, but the 19n20C are pretty much a no go. There are plenty out there, but i have found a 100% fake rate. No one has original boxes, and without it, your chances are sketchy at best. There are over 50,000 of these things floatig around in Asia, some being made in 10' and later. That should tell you all you need to know. There are two other 19n20 parts, the standard version, and the "l" version, both with increasing Yfs and Ciss. Of these two, the standard part is a better match on paper, the 19n20"L" part has double the Yfs(transconductance) and double the Ciss. THis is still available. Another EOL part that i think matches better on paper is the 12n25C. It is EOL, but still available, the question being one of sufficient quantity. OTher than these parts, the only new parts i found that look close are the FQA32N20C and FQA28N15. Other than these, we have the option of the smaller die package FQP of the original parts. I am going to start a poll so that we can vote. I'll look at the results and we will go from there. Please let anyone on the orginal GB know.

fdlsys 7th April 2012 05:11 PM

Paapaaaa!!! Help!! :crying:

Gyuri 7th April 2012 05:51 PM

Sometimes I have that feeling of mine, Papa makes his amplifiers from unattainable components, because it is not possible to make a copy from these so.
This was a malicious comment now.

Let somebody correct me if this is not so.

fdlsys 7th April 2012 06:22 PM

Quote:

Originally Posted by Gyuri (Post 2976418)
Sometimes I have that feeling of mine, Papa makes his amplifiers from unattainable components, because it is not possible to make a copy from these so.
This was a malicious comment now.

Let somebody correct me if this is not so.

Would it make any difference even if a 100 of us corrects you?

buzzforb 7th April 2012 06:25 PM

Quote:

Originally Posted by Gyuri (Post 2976418)
Sometimes I have that feeling of mine, Papa makes his amplifiers from unattainable components, because it is not possible to make a copy from these so.
This was a malicious comment now.

Let somebody correct me if this is not so.

I think that may be a stretch. You could have gotten these components easily when the F4 was released. One ofthe early builders, Cviller, made it well known these were the components used by Nelson.

Gyuri 7th April 2012 06:33 PM

3 Attachment(s)
As mentioned above, this was just a malicious comment.
You know, I am like that than Gargamel.
Ugly old small bald evil.


I was thinking about these, but not good:

Gyuri 7th April 2012 06:40 PM

An evil comment has some truth content because of that.
The small signal J-FET transistors are obsolete products as well.

Zen Mod 7th April 2012 07:31 PM

well

if you count a number of his schmtcs given to Greedy Boyz , there is more made of regular and easy obtainable parts , then these made of preputium

regarding those - even small Toshibas aren't too much of a problem , even for guys living on this side of Iron Curtain

buzzforb 7th April 2012 08:54 PM

I agree that it is not too big of a deal. There are alternatives, including Fairchild options mentioned. I was trying to keep the P part which is what Nelson highlighted. P3 ishuge help any way you go. I even tried fakes in amp. Sounded normal, slight oscillation problem though. I am going to get all the alternatives of FQA parts and compare them to good "c" part. Should have some real info to look at.

pcb121055 8th April 2012 01:04 AM

However this plays out, this is a great effort on your part buzzforb. Thank you!


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