is it necessary to match 2sj162&2sk1058

[umut1001]

hi everybody..i was looking for 2sj162and 2sk1058 transistors for a long time in my country..and at the end i found them..i measured the gate-drain voltage of them..it is 0.57v and the other one is 0.63 v ..now some people say it is not necessary to match these lateral mosfets..what do you think about them?should i match them?i want to make a class a amp..i need to make a good pcb for it..it is very difficult to make a class a amp..every component have to be matched..so what do you think everyone?should i match 2sj and 2sk?

 

[Zen Mod]

hi everybody..i was looking for 2sj162and 2sk1058 transistors for a long time in my country..and at the end i found them..i measured the gate-drain voltage of them..it is 0.57v and the other one is 0.63 v ..now some people say it is not necessary to match these lateral mosfets..what do you think about them?should i match them?i want to make a class a amp..i need to make a good pcb for it..it is very difficult to make a class a amp..every component have to be matched..so what do you think everyone?should i match 2sj and 2sk?

depends .......

show us schematic and than we can tell you for sure .......

in any case - if you match them,you'll have better symmetry ;
in case that you must use multiple pairs , matching is necessary

 

[umut1001]

schematic

for example this circuit..

and i need a good class a pcb..i am working and i have not much time to draw it..would you send me a class a pcb ..will work at + -35 volts?

 

[Zen Mod]

Re: schematic

for example this circuit..

and i need a good class a pcb..i am working and i have not much time to draw it..would you send me a class a pcb ..will work at + -35 volts?

ya nutz ?



that's my circ - in fact my friend Oly made this little schematic .
you didn't follow exact thread where this is posted ; somewhere in start of Babelfish J thread

it's intended for IRF150 (or IRFP150 , whatever ) and his cousin IRF(P)9150 ; matching isn't so crucial there .
you can use 2SJ and 2SK with slight recalculation of drain resistors of Q1 and Q2 .

and - it isn't too wise to make it with more than 2x 25V

I have somewhere graphical files for that pcb ...... is that what you need ?

EDIT:

now I remember that Turks slaved Serbs for 600 yrs........ I will not help you with this .........

hehe, just joking,off course

 

[umut1001]

schematic

yes i need a schematic and pcb..my friend made a class a amplifier works at+-24 volts..it is working with irf540 and 9540..but the current was not stable enough..i will use 2sj162 and 2sk1058..if you send me schematics and pcb i will be happy thank you very much

 

[Zen Mod]

Re: schematic

yes i need a schematic and pcb..my friend made a class a amplifier works at+-24 volts..it is working with irf540 and 9540..but the current was not stable enough..i will use 2sj162 and 2sk1058..if you send me schematics and pcb i will be happy thank you very much

well - for stability you need to place input jfets in tight position , same as on this pic:

 

[Zen Mod]

that's last , tested schematic

 

[umut1001]

post me pcb pls

yes i know it..my friend is tieing transistors like this..dont you have a pcb that works in Ares ?

 

[Zen Mod]

and that's what I have regarding pcb ;
now you need just little work in some graphic progie .......
dunno is it scaled.......

 

[umut1001]

thanks

thank you is it working well? which transistors are being used for Q3 andQ4..can i use 2sj162 for it by changing the bias?

 

[umut1001]

see you soon

and what do you think about single ended amps and this Babelfish J..which one sounds well?..now i need to sleep i am ill..thank you for interest..my name is Umit and i am an electronics engineer works on ip-telephones and loves diy amplifiers..good bye see you soon

 

[Zen Mod]

Re: thanks

thank you is it working well? which transistors are being used for Q3 andQ4..can i use 2sj162 for it by changing the bias?

sorry- I attached wrong picture in post No.7 ; there is right one ;
you can use 2SJ and 2Sk in output if you almost halve drain resistors for 2sj109 AND 2sk389

 

[umut1001]

class a compatible transistors

hi again..we discussed with friends that irfp mosfets are not good for a diy class a amplifier..because it is not designed for working at full load everytime and makes crossover distortion..and in this circuit the cutoff voltage of 2sj and2sk is different then the irfp140 and 9140..irfp's have 4volts of Vgs(thresold voltage)and 2sj has about 0.6volts..

whatever i will try this circuit with irfp240 and 9240..i matched them and have 5twins..later i will use 2sj and 2sk

 

[umut1001]

IRFP-2sj

is there anyone that makes a stable class a amplifier with IRFP mosfets?

 

[Zen Mod]

Re: IRFP-2sj

is there anyone that makes a stable class a amplifier with IRFP mosfets?

did you really searched?

you missed entire subforum ........ which will die without IRFs in output

 

[umut1001]

sorry

sorry i can not understand..i just need a class a amplifier that really works with 2sj..because it is expensive and i have only 2pairs..i dont want to burn them

 

[Zen Mod]

Re: sorry

sorry i can not understand..i just need a class a amplifier that really works with 2sj..because it is expensive and i have only 2pairs..i dont want to burn them

just save those 2SJ/2SK for next amp,specifically constructed with that type of mosfets .
for this amp use whatever you have in nearest electronic parts shop - , but possibly IRFP150/IRFP9150 ;

they are also cheaper ..........

regarding xover distortion in amps, in A class you don't have xover distortion ......... at least not until insane output levels

 

[umut1001]

i will make your 12.post circuit..i will use irfp240and 9240..i hope it works..

 

[Nico Ras]

Hi guys I stumbled upon this thread. Remeber 2SK1058 and 2SJ162 pin configuration is not the same as IRF...

 

[umut1001]

is the gate source voltage same as irfp240's ? i matched irfps by using a 150ohms resistor and 15volts..i wired gate and drain together and measured gate to source voltage of irfp240s..and it is about 0.63 volts on 2sj mosfets.someone says it must be about 4 volts too.are my 2sj mosfets fake or genuine?