JFET complementary pair

Leolabs · 1st January 2006, 03:54 AM

What's your recommendations for use as input stage of a fully symmetrical push pull amp???American,European or Japanese???
2Ns,2Ss or BFs????

mastertech · 1st January 2006, 04:35 AM

You know the Japanese beat the whole american semiconductor
industry in the mid-80s in both quality and technology from
transistors to memory and cpus the europeans werent considered
as powerful as yankies and japs at the time so if you think the
japs dont make good quality semis think twice!

mirlo · 1st January 2006, 04:47 AM

Japanese CPUs??

For microcontrollers, OK.

Not PCs

But Japanese (Toshiba) JFETs rule.

2sk170/2sj74

amplifierguru · 1st January 2006, 05:05 AM

Yes Mirlo,

...."But Japanese (Toshiba) JFETs rule.

2sk170/2sj74"....

I used these in the Magnet PR9R folded cascode preamp which was a runaway success in Thailand, was their most successful preamp ever and has been a flagship product for 10 years. Even rebadged as a US brand along with the 300F power amp, rated TAS Golden Ear award.

Yes, matched K170/J74 cut it!

Cheers,
Greg

MikeB · 1st January 2006, 11:45 AM

Yes, 2SK170/2SJ74 rule !
If you're going to use a fully symetrical jfet input, you might consider the attached configuration. This showed excellent constant current in real world and reduces part count heavily.
Don't forget to cascode them, the sj74 has max vds of 25v.

Mike

Leolabs · 1st January 2006, 03:32 PM

Any recommendation on the 2Ns?????

tvi · 1st January 2006, 03:52 PM

As far as I know only the Japanese made Dual p-channel JFETs.

If you are matching your own what specs are important?

Have A look at american micro semiconductor and linear systems

Regards
James

mastertech · 1st January 2006, 07:19 PM

mirlo

Japanese CPUs??

For microcontrollers, OK.

Not PCs

But Japanese (Toshiba) JFETs rule.

2sk170/2sj74
-------------------------------------------------
whats so special about cpus americans had a standard there
x86 that protected them, intel is a lousy technology in cpus other
american companies like Zilog and Motorola kicked their butts with
better processors and better standards that didnt take off because of intel's standard in the marketplace that still gives them
a free ride with whatever crap they come up with, at the time
americans had fallen 6 years behind in technology and there was
no hope in sight then the american goverment took protecting
measures to save the industry and the japs pulled out once there
was no more market for them there especially in the microprocessor business

amplifierguru · 1st January 2006, 08:11 PM

This little US outfit is worth a look at as well -

www.interfet.com

Cheers,
Greg

darkfenriz · 1st January 2006, 08:16 PM

Quote:

Originally posted by Leolabs
Any recommendation on the 2Ns?????

2n3819/2n3820 ?
I didn't use them but datasheets look good and they are relatively cheap in Poland (same price as 2sc5200 power bjt. and twice cheaper than sk389/sj109).

Anyone used them?
Listening impressions?

regards

1st January 2006, 03:54 AM	#1
Leolabs diyAudio Member Join Date: Dec 2004 Location: Bukit Mertajam	JFET complementary pair What's your recommendations for use as input stage of a fully symmetrical push pull amp???American,European or Japanese??? 2Ns,2Ss or BFs????

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1st January 2006, 04:35 AM	#2
mastertech Banned Join Date: Mar 2005 Location: Australia	You know the Japanese beat the whole american semiconductor industry in the mid-80s in both quality and technology from transistors to memory and cpus the europeans werent considered as powerful as yankies and japs at the time so if you think the japs dont make good quality semis think twice!

1st January 2006, 04:47 AM	#3
mirlo diyAudio Member Join Date: Jul 2002 Location: San Diego	Japanese CPUs?? For microcontrollers, OK. Not PCs But Japanese (Toshiba) JFETs rule. 2sk170/2sj74

1st January 2006, 05:05 AM	#4
amplifierguru Account Disabled Join Date: Aug 2004 Location: Earth	Yes Mirlo, ...."But Japanese (Toshiba) JFETs rule. 2sk170/2sj74".... I used these in the Magnet PR9R folded cascode preamp which was a runaway success in Thailand, was their most successful preamp ever and has been a flagship product for 10 years. Even rebadged as a US brand along with the 300F power amp, rated TAS Golden Ear award. Yes, matched K170/J74 cut it! Cheers, Greg

1st January 2006, 03:32 PM	#6
Leolabs diyAudio Member Join Date: Dec 2004 Location: Bukit Mertajam	Any recommendation on the 2Ns?????

1st January 2006, 03:52 PM	#7
tvi diyAudio Member Join Date: Apr 2001 Location: Moonee Ponds, Vic, Australia	As far as I know only the Japanese made Dual p-channel JFETs. If you are matching your own what specs are important? Have A look at american micro semiconductor and linear systems Regards James

1st January 2006, 07:19 PM	#8
mastertech Banned Join Date: Mar 2005 Location: Australia	mirlo Japanese CPUs?? For microcontrollers, OK. Not PCs But Japanese (Toshiba) JFETs rule. 2sk170/2sj74 ------------------------------------------------- whats so special about cpus americans had a standard there x86 that protected them, intel is a lousy technology in cpus other american companies like Zilog and Motorola kicked their butts with better processors and better standards that didnt take off because of intel's standard in the marketplace that still gives them a free ride with whatever crap they come up with, at the time americans had fallen 6 years behind in technology and there was no hope in sight then the american goverment took protecting measures to save the industry and the japs pulled out once there was no more market for them there especially in the microprocessor business

1st January 2006, 08:11 PM	#9
amplifierguru Account Disabled Join Date: Aug 2004 Location: Earth	This little US outfit is worth a look at as well - www.interfet.com Cheers, Greg

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