What's your recommendations for use as input stage of a fully symmetrical push pull amp???American,European or Japanese???
2Ns,2Ss or BFs????
2Ns,2Ss or BFs????
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!
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!
Japanese CPUs??
For microcontrollers, OK.
Not PCs
But Japanese (Toshiba) JFETs rule.
2sk170/2sj74
For microcontrollers, OK.
Not PCs
But Japanese (Toshiba) JFETs rule.
2sk170/2sj74
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
...."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
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
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
Attachments
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
If you are matching your own what specs are important?
Have A look at american micro semiconductor and linear systems
Regards
James
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
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
Leolabs said:
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
darkfenriz said:
1/4 of the gm and 6 x noise of 389/109 means they
are totally different devices.
cheers,
Terry
2N5401 2N5551
are two good and useful complementary TO92 transistors
They take 150 V and 625 mW
but,
these are bipolar, BJT and not JFET
To find very good matching complementary N-JFETs and P-JFETs
is impossible, as far as I know.
Same goes for N- and P- MOSFETs.
Not even bipolar NPN and PNP are ever perfectly matched complementary.
Nevertheless you can use them as pairs
with good result in most cases.
are two good and useful complementary TO92 transistors
They take 150 V and 625 mW
but,
these are bipolar, BJT and not JFET
To find very good matching complementary N-JFETs and P-JFETs
is impossible, as far as I know.
Same goes for N- and P- MOSFETs.
Not even bipolar NPN and PNP are ever perfectly matched complementary.
Nevertheless you can use them as pairs
with good result in most cases.
If you're looking for high transconductance, consider the following:
* 2N6550 (100mAtyp, .3<Vgs<3, 25<Gfs<150mS, Goss<150uS).
* Interfet U290-U291 (500mAmin, 4<Vgs<10, 350mStyp, 100pF, .7nV/sqHz).
* Interfet IF1801 (30mAmin, .35<Vgs<2, >50mS, 100pF, .5nV/sqHz).
* Interfet IF3602 (Dual, 30mAmin, .35<Vgs<3, 750mStyp, 300pF, .3nV/sqHz).
* 2N6550 (100mAtyp, .3<Vgs<3, 25<Gfs<150mS, Goss<150uS).
* Interfet U290-U291 (500mAmin, 4<Vgs<10, 350mStyp, 100pF, .7nV/sqHz).
* Interfet IF1801 (30mAmin, .35<Vgs<2, >50mS, 100pF, .5nV/sqHz).
* Interfet IF3602 (Dual, 30mAmin, .35<Vgs<3, 750mStyp, 300pF, .3nV/sqHz).
Leolabs said:
I used 2N5461/2N5458 in my Pre-amp DB-01's VAS stage, Q3,Q4 are 2N5461 and Q17 is 2N5458 as a current source.
Yes Terry,
What you say is true and they would be totally unsuited to MM or MC use, but for high level pre- or pwr-amp input there should be little practical noise degradation and the lower transconductance an advantage for bandwidth and stability of the whole amp.
Horses for courses.
Cheers,
greg
What you say is true and they would be totally unsuited to MM or MC use, but for high level pre- or pwr-amp input there should be little practical noise degradation and the lower transconductance an advantage for bandwidth and stability of the whole amp.
Horses for courses.
Cheers,
greg
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