Semisouth power jfet question

DJNUBZ · 30th June 2011, 06:59 PM

Ok two questions.

1. Since these are high V devices could you just drop them in place of a tube in a tube amp? I am sure that you would have to tweek a few things but would it work or would it be a major overhaul of a circuit and not worth the time.

2. Could I replace my IRFP240 and IRFP9240 with SJEP120R100 and SJEP120R100A or SJEP120R063 and SJEP120R063 in my F5 amp? If so I think that power jfets may be the next evolution in audio since solid state.

Zen Mod · 30th June 2011, 07:12 PM

no

no

horses for courses ; in first case - major overhaul - different OPT is needed for SS instead of tube

in second case - F5 is made with complementary devices , and you don't have complementary SS-es

DJNUBZ · 30th June 2011, 07:28 PM

SJEP120R100 and SJEP120R100a aren't complimentary?

Zen Mod · 30th June 2011, 07:57 PM

nope

DJNUBZ · 30th June 2011, 07:59 PM

disappointing.

Whats the difference between SJEP120R100 and SJEP120R100A and a regular complimentary pair?

Zen Mod · 30th June 2011, 08:36 PM

rephrase question

writing War & Peace isn't exactly purpose of public forum

edit :

main difference with these two is that they aren't complimentary pair , at all

qusp · 30th June 2011, 08:50 PM

Quote:

Originally Posted by DJNUBZ

disappointing.

Whats the difference between SJEP120R100 and SJEP120R100A and a regular complimentary pair?

everything, they arent complimentary

Nelson Pass · 1st July 2011, 12:47 AM

The SemiSouth Jfets are N channel parts only. I am unaware of a
company making complementary (N and P channel) power Jfets since
Sony in the 70's.

DJNUBZ · 1st July 2011, 02:48 PM

Sorry guys I totally misread something on semisouth's site.

Is Semisouth working on complementary pairs?

I am still a newbie with amp design.

There aren't complementary pairs of semisouth power jfets; does that mean that you can only build single ended ouput amplifiers with what is currently available?

buzzforb · 1st July 2011, 02:58 PM

No. You still have the ability to build quasi-complimentary amps Like the J2 or Aleph J. THink tube topologies. THere are only N channel equivalent tubes. I have not been doing this long, so i feel for you, but you need to take some time and do some reading. Go to the firstwatt site and read the articles, starting with the Zen amp. Don't breeze through them. Read them until you understand them. If you don't understand something, ask. There are many here to help, even if they do poke fun at you while doing so. Good Luck.

30th June 2011, 06:59 PM	#1
DJNUBZ diyAudio Member Join Date: May 2003 Location: Chicago	Semisouth power jfet question Ok two questions. 1. Since these are high V devices could you just drop them in place of a tube in a tube amp? I am sure that you would have to tweek a few things but would it work or would it be a major overhaul of a circuit and not worth the time. 2. Could I replace my IRFP240 and IRFP9240 with SJEP120R100 and SJEP120R100A or SJEP120R063 and SJEP120R063 in my F5 amp? If so I think that power jfets may be the next evolution in audio since solid state.

30th June 2011, 07:12 PM	#2
Zen Mod diyAudio Member Join Date: Jan 2003 Location: ancient Batsch , behind Iron Curtain	no no horses for courses ; in first case - major overhaul - different OPT is needed for SS instead of tube in second case - F5 is made with complementary devices , and you don't have complementary SS-es __________________ my Papa is smarter than your Nelson ! tnx to clean thread ; Cook Book ; PSM LS Cook Book ; Baby Diyaudio FORUM ; BAF Forum & Gallery;I'm dumb

30th June 2011, 07:57 PM	#4
Zen Mod diyAudio Member Join Date: Jan 2003 Location: ancient Batsch , behind Iron Curtain	nope __________________ my Papa is smarter than your Nelson ! tnx to clean thread ; Cook Book ; PSM LS Cook Book ; Baby Diyaudio FORUM ; BAF Forum & Gallery;I'm dumb

30th June 2011, 08:36 PM	#6
Zen Mod diyAudio Member Join Date: Jan 2003 Location: ancient Batsch , behind Iron Curtain	rephrase question writing War & Peace isn't exactly purpose of public forum edit : main difference with these two is that they aren't complimentary pair , at all __________________ my Papa is smarter than your Nelson ! tnx to clean thread ; Cook Book ; PSM LS Cook Book ; Baby Diyaudio FORUM ; BAF Forum & Gallery;I'm dumb

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30th June 2011, 07:28 PM	#3
DJNUBZ diyAudio Member Join Date: May 2003 Location: Chicago	SJEP120R100 and SJEP120R100a aren't complimentary?

30th June 2011, 07:59 PM	#5
DJNUBZ diyAudio Member Join Date: May 2003 Location: Chicago	disappointing. Whats the difference between SJEP120R100 and SJEP120R100A and a regular complimentary pair?

1st July 2011, 12:47 AM	#8
Nelson Pass The one and only Join Date: Mar 2001	The SemiSouth Jfets are N channel parts only. I am unaware of a company making complementary (N and P channel) power Jfets since Sony in the 70's.

1st July 2011, 02:48 PM	#9
DJNUBZ diyAudio Member Join Date: May 2003 Location: Chicago	Sorry guys I totally misread something on semisouth's site. Is Semisouth working on complementary pairs? I am still a newbie with amp design. There aren't complementary pairs of semisouth power jfets; does that mean that you can only build single ended ouput amplifiers with what is currently available?

1st July 2011, 02:58 PM	#10
buzzforb diyAudio Member Join Date: Oct 2010 Location: Burlington, NC	No. You still have the ability to build quasi-complimentary amps Like the J2 or Aleph J. THink tube topologies. THere are only N channel equivalent tubes. I have not been doing this long, so i feel for you, but you need to take some time and do some reading. Go to the firstwatt site and read the articles, starting with the Zen amp. Don't breeze through them. Read them until you understand them. If you don't understand something, ask. There are many here to help, even if they do poke fun at you while doing so. Good Luck.

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