2SK/irfp lateral vertical mosfet amplifier HELP ??

[medogrizli]

So I am searching for +/70 V Mosfet amplifier schematics

Are 2sk campatibile with irfp240 Can i in certain schematics replace this two mosfet types?

If nost why ?


What are pros and cons of each mosfet type ?

Is there any difference in soud qualitiy


thanks

[jackinnj]

the lateral mosfet's are a bit more difficult to find and somewhat more expensive -- but they have the advantage of no thermal runaway.

the bias for lateral mosfets is much, much lower -- reduce the values of the resistors in the VBE multiplier --

[medogrizli]

Originally posted by jackinnj
the lateral mosfet's are a bit more difficult to find and somewhat more expensive -- but they have the advantage of no thermal runaway.

the bias for lateral mosfets is much, much lower -- reduce the values of the resistors in the VBE multiplier --

Isnt 2skxxxx lateral ?


Do you have some links where is described the difference between vertical and lateral ?

[richie00boy]

2sk/sj are lateral. They don't suffer thermal runaway and are quite linear, they are made for audio. The pinout is GSD.

IRF are vertical. They are made for switching but often used in amps designed properly for them, successfully. The pinout is GDS.

Lateral can be used in an amp for vertical design, but the bias thermal tracking must be attended to and the bias voltage must be lowered. You cannot use vertical in an amp designed for lateral as it will quickly heat up and die.

[medogrizli]

Originally posted by richie00boy
2sk/sj are lateral. They don't suffer thermal runaway and are quite linear, they are made for audio. The pinout is GSD.

IRF are vertical. They are made for switching but often used in amps designed properly for them, successfully. The pinout is GDS.

Lateral can be used in an amp for vertical design, but the bias thermal tracking must be attended to and the bias voltage must be lowered. You cannot use vertical in an amp designed for lateral as it will quickly heat up and die.

I can not translate "bias" in my local language : can you describe whats that

Thermal runaway means that they start better conduction drain source when temperature rising : But thats not bad : it can preserve amplifier from breakdown if no properly cooled

So whats the difference in SOUND qualitiy between IRFP and 2SK mosfet amplifier

so can lateral amplifier be modified for using vertical mosfets?

Are there any -/+ good working schematcs for IRFP and 2SK mosfets
here on the forum

thanks

[jackinnj]

Originally posted by medogrizli


I can not translate "bias" in my local language : can you describe whats that

Thermal runaway means that they start better conduction drain source when temperature rising : But thats not bad : it can preserve amplifier from breakdown if no properly cooled

So whats the difference in SOUND qualitiy between IRFP and 2SK mosfet amplifier

so can lateral amplifier be modified for using vertical mosfets?

Are there any -/+ good working schematcs for IRFP and 2SK mosfets
here on the forum

thanks

BIAS -- it's just a little voltage to get the device to "go" -- in the case of a MOSFET it gets the device to that point at which it will respond linearly to voltage.

You can adapt an amplifier which used lateral mosfet's to vertical but it will require different bias voltage, and as pointed out previously, the pinouts are different. Among the most popular DIY amps ever built are those by Nelson Pass using the International Rectifier IRFp240 and IRFP9240.

There are a couple of good designs on the Elliot Sound Products website. Other FET designs can be found on PASSDIY and on Erno Borbely's site.

[richie00boy]

Originally posted by medogrizli
I can not translate "bias" in my local language : can you describe whats that

It is the 'standing voltage' applied to bring the device just into useful conduction.

Originally posted by medogrizli
Thermal runaway means that they start better conduction drain source when temperature rising : But thats not bad : it can preserve amplifier from breakdown if no properly cooled

Sorry but that is completely wrong. More heat forces more current which makes more heat which forces more current... bang

Originally posted by medogrizli
So whats the difference in SOUND qualitiy between IRFP and 2SK mosfet amplifier

Sound quality is subjective. In my opinion it's as much to do with the amplifier topology as the output devices and other parts.

Originally posted by medogrizli
so can lateral amplifier be modified for using vertical mosfets?

Yes but usually it's not worth the hassle.

Originally posted by medogrizli
Are there any -/+ good working schematcs for IRFP and 2SK mosfets
here on the forum

thanks

Yes there are good, and bad. I'm afraid you will have to search yourself.

[Nelson Pass]

Originally posted by richie00boy
You cannot use vertical in an amp designed for lateral as it will quickly heat up and die.

Of course that is not literally correct.

[medogrizli]

Originally posted by jackinnj


BIAS -- it's just a little voltage to get the device to "go" -- in the case of a MOSFET it gets the device to that point at which it will respond linearly to voltage.

You can adapt an amplifier which used lateral mosfet's to vertical but it will require different bias voltage, and as pointed out previously, the pinouts are different. Among the most popular DIY amps ever built are those by Nelson Pass using the International Rectifier IRFp240 and IRFP9240.

There are a couple of good designs on the Elliot Sound Products website. Other FET designs can be found on PASSDIY and on Erno Borbely's site.

Do you have schematics of Nelson Pass ? or link?

[Leolabs]

Hi,please specified the circuit configuration you are interested,ie single-ended or diffirential amp base input or fully push-pull................