MOSFET power amp schematic

[Leolabs]

What's your recommendations,esp for use with the old 2SJ50/2SK135???

 

[edl]

Dear Laolabs,

A schema attached.
If you have any question about the schema, let's ask.

Regards

 

[lilouxhk]

How dose this amp sound? Any idea?
I want a 20w class A mosfet amp with this output pair; does it work or not?

thanks

 

[djk]

200W into 8 ohms.

http://img.photobucket.com/albums/v357/still4given/soundcraftsman/soundcraftsmen2.jpg

 

[johnnyx]

Have a look in this thread. Take note of the issue with the 100 ohm gate stopper resistors, I had a problem with this that was described towards the end of the thread, increase them to 200 ohms or so. This also applies to the Exicon replacement devices;- same problem.

 

[Leolabs]

Thanks all for your replies.But I have build that with differential amp base input,which I believed taken from Hitachi's application notes.What I am looking for is kind that fully complementary,without differential amp,and yet simple enough with maybe 6 to 8 devices per channel,but definitelly not a single-ended one

 

[Rick NL]

Look at the Zenquito from mr Plantfeve at http://perso.wanadoo.fr/jm.plantefeve/sche.html
With one set of output devices and 2 x 18 VAC (2 x 25 VDC) it should be a perfect solution for your requirements.
Six devices total and about 25 Watt's in 8 Ohm.
Haven't build this one so I cannot say anything on how it sounds, but I have read good reviews.

Succes,

Rick

 

[Rick NL]

As a remark to my post I might say that with a 2 x 15 VAC (2x 21 VDC) the dissipation on a single output pair would be more at the safe side. Still around 16 Watts in 8 Ohm.

Rick

 

[bear]

Fully complementary?

DC coupled?

Borbely.

http://www.borbelyaudio.com

also articles published in TAA/Audio Express and in Euro publications too.

_-_-bear

PS. plus they sound and measure well too.

 

[Leolabs]

Thanks Rick for the website .Thanks Bear for the Borberly,but Borberly's circuits are quite complex,and I really dont want any differential amp input.

 

[bear]

Yeah, sorry, after I posted the Borbely suggestion, I realized that you were going for a SE input design.

And simplicity...

Oh, iirc the original B&K amps were SE input stage... something to maybe look at (?).

The next question to ask is why?
What are you going for?
Are you looking for additional even order harmonics??

And, btw, the Borbely stuff isn't terribly complex assuming you get the PC boards from him or Audio Express's site... the class A stuff is quite sweet, imho... and it eliminates the problem of the smoke escaping from the little furry Fets (for the most part).

_-_-bear