hi, sorry about insist but, what i want to know is the fets that can be used in audio amps, because its not every fet that can be used for this. its because where i live have just too few mosfets for sale, and if i know wich ones can be used and how to build the amplifier i could get somewhere 
thanks
thanks
Some FETs are better suited for switching application's, this is true.
But all FET's can be used in a analog circuit as well.
A engineer from TI explained that to me once when I asked him a similar question.
The First place to start is to learn how FET's work as compared to Bipolar Junction transistors (BJT's) and their differences.
FWIW
jer
But all FET's can be used in a analog circuit as well.
A engineer from TI explained that to me once when I asked him a similar question.
The First place to start is to learn how FET's work as compared to Bipolar Junction transistors (BJT's) and their differences.
FWIW
jer
hi, sorry about insist but, what i want to know is the fets that can be used in audio amps, because its not every fet that can be used for this. its because where i live have just too few mosfets for sale, and if i know wich ones can be used and how to build the amplifier i could get somewhere
thanks
If you replace BJT with mosfet with minor modification to get "just work" then you will conclude that mosfet is not good for audio amp.
Mosfet have different character (ex. high input impedance, high input capacitance, etc) than BJT, and the circuit/schematic to use them must optimize by its character to get low THD, high slew rate, etc.
Sorry, it does not work that way.
That´s better.
Link some project you liked, then mabe we can suggest some replacement.
Mmmmmhhhhh, not that easy.
If inexperienced, first learn basic Electronics, how to solder, how to measure with a multimeter and start by building some simple projects.
Step by step.
EDIT: and tell us where you are from, so we can suggest suppliers.
Can you buy from EBay or USA suppliers such as Mouser or Digikey?
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I know a few things of eletronic, bjt its just a little bit. I will learn the basics. Well i had to format my pc so i lost the projects, but one i would like to build is this
DIY Class-A 2SK1058 MOSFET Amplifier Project
But i didn't found the fet to buy in my country. I live in Brazil. There's another fet that can be used?
Thank you very much
DIY Class-A 2SK1058 MOSFET Amplifier Project
But i didn't found the fet to buy in my country. I live in Brazil. There's another fet that can be used?
Thank you very much
Just checked , no lateral/audio MosFets available in Brazil.
Only vertical/switching/HexFets .
But you can search for those suggested by Mooly, which are equivalent to the old Hitachi/Toshiba 2SK and buy them in USA or England with your Credit Card.
Small packages have no Customs/Alfândega problems because you pay no taxes on less than 50U$ purchases.
As a side note, just to practice, build that circuit with a *switching* type Mosfet, say an IRFP240 or 250 which costs around 6 R$ in São Paulo.
It *will* work, remember to bias it to 12V on its source with 24V power supply.
Switchers are reasonably linear at high currents and yours uses 12V into 15 ohms which is almost 1 Ampere.
Not the original but it will not sound bad.
And when you get the original MosFet, replace it.
Only vertical/switching/HexFets .
But you can search for those suggested by Mooly, which are equivalent to the old Hitachi/Toshiba 2SK and buy them in USA or England with your Credit Card.
Small packages have no Customs/Alfândega problems because you pay no taxes on less than 50U$ purchases.
As a side note, just to practice, build that circuit with a *switching* type Mosfet, say an IRFP240 or 250 which costs around 6 R$ in São Paulo.
It *will* work, remember to bias it to 12V on its source with 24V power supply.
Switchers are reasonably linear at high currents and yours uses 12V into 15 ohms which is almost 1 Ampere.
Not the original but it will not sound bad.
And when you get the original MosFet, replace it.
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