Can i replace MPF102/2N5951 with 2SK30A(K30A)?

[Crontox102098]

Can i replace MPF102 with 2SK30A(K30A)? Just that, i didn't get information from Google.  

[PRR]

Sometimes.

They sure are not identical, but some circuits are not too fussy.

So It Depends.

[Crontox102098]

Sometimes.

They sure are not identical, but some circuits are not too fussy.

So It Depends.

Some example... the Noisy Cricket request some MPF102, can i replace it with K30A?

[J0K3RX]

Can i replace J201 with 2SK30A(K30A)? Just that, i didn't get information from Google.  

I seem to remember that you asked this same question a couple weeks ago...?  Let me take a wild guess, you didn't understand completely?
http://www.diystompboxes.com/smfforum/index.php?topic=108507.msg989327#msg989327

1. Can you tell us what pedals you want to use the 2SK30 in?  I am guessing that these pedals are calling for J201's and you have a bunch of 2SK30's? I see you answered  this while I was posting
2. There is basically only one J201 unless you include the J202 and J203 but, you are asking specifically about the J201
3. There are four (4) different classifications for the 2SK30, which ones do you have or which ones do you plan on getting, do you know?

They are all labeled K30A but, they all not all the same. They all have different "Electrical Characteristics" mainly Drain current/IDSS

2SK30A-R
2SK30A-O
2SK30A-Y
2SK30A-GR

You have to pay attention to and understand the data sheet!

The J201 and the 2SK30A-R would be the closest match.  The 2SK30A-R is better than the J201 but, I doubt that what you have or what you thinking of getting have the "R" marking on them!?

2SK30A-R
IDSS  /  0.3~0.75

J201
IDSS  /  0.2~1.0

And, obviously the noise difference among other things...

So, the answer is yes you can use them in place of J201's but, as R.G. pointed out in your last post, you may have to tinker with biasing and gain resistors...

[Blitz Krieg]

2. There is basically only one J201 unless you include the J202 and J203 but, you are asking specifically about the J201

there are a ton of numbers in the MPF series, but only mpf102 gets use.  why?

[Crontox102098]

Sorry J0K3RX, i did understand on the other post, not completely, but i understand, and my last stomp is running well with it (K30A-R). This time im asking if i can replace MPF102 with K30A (i have a bunch of it) as the title of the thread can say... I forgot to change J201 with MPF102.

Thanks, cheers!

[J0K3RX]

Sorry J0K3RX, i did understand on the other post, not completely, but i understand, and my last stomp is running well with it (K30A-R). This time im asking if i can replace MPF102 with K30A (i have a bunch of it) as the title of the thread can say... I forgot to change J201 with MPF102.

Thanks, cheers!

Honestly, I am jealous of you!  The 2SK30A-R are very hard to find and when you do find them they are in very limited supply. If you can find them for good price in a realitivly large qty they are in China and highly suspicious!! If I were you I would not waste them on circuits where they will not be of much benifit if any at all! The 2SK30A-R are highly sought after by high gain junkies like myself...! They have very high gain with very low noise and are perfect for high gain JFET preamps! They are used almost exclusively in AMT pedals etc.. But they belong to you so use them for whatever you like... As for using them in a noisy cricket I'm not sure since I am not familiar with it and I am on my cell phone right now. I am sure you could get it to work but might have to make some changes...

[Crontox102098]

Sorry J0K3RX, i did understand on the other post, not completely, but i understand, and my last stomp is running well with it (K30A-R). This time im asking if i can replace MPF102 with K30A (i have a bunch of it) as the title of the thread can say... I forgot to change J201 with MPF102.

Thanks, cheers!

Honestly, I am jealous of you!  The 2SK30A-R are very hard to find and when you do find them they are in very limited supply. If you can find them for good price in a realitivly large qty they are in China and highly suspicious!! If I were you I would not waste them on circuits where they will not be of much benifit if any at all! The 2SK30A-R are highly sought after by high gain junkies like myself...! They have very high gain with very low noise and are perfect for high gain JFET preamps! They are used almost exclusively in AMT pedals etc.. But they belong to you so use them for whatever you like... As for using them in a noisy cricket I'm not sure since I am not familiar with it and I am on my cell phone right now. I am sure you could get it to work but might have to make some changes...

I purchased 200 of it (100: K30A-R and 100: K30A-GR) in a local store for 20 bucks approximately... So... what you say about K30A-GR?

[PRR]

Put in a socket. Try it.

JFET biasing and operation is not SO complicated, but far from a yes/no thing. Working out the specs takes much longer than stuffing a socket and twanging some chords.

[Crontox102098]

Put in a socket. Try it.

JFET biasing and operation is not SO complicated, but far from a yes/no thing. Working out the specs takes much longer than stuffing a socket and twanging some chords.

I'll try, thanks for all your suggestions 

Cheers!