Jfet input, Lateral output 2nd version

[Tekko]

Heres something i plan to try, using the laterals i got in the big transistor score a few months ago:

http://i.imgur.com/xhqtH.png

In simulation it sez flat from DC to 400kHz and a dc offset of 60-100 microvolts with the input floating and 1millivolt with the input shorted to ground. Around 50-100 watts per channel with a 2x35-45VDC 300VA psu.

I yet don't know if this will actually work in reality but i think it should, may try it this coming weekend if i feel up to it.

I also plan to use a very similar jfet input stage in a big subwoofer amplifier using five pairs of MJW21195's and MJW21196's with MJL4281 and MJL4302 as drivers, i expect up to 500 watts short term(pulse) and around 300 watts continous into 4 ohms from this one as my biggest psu is 500VA and offers around 2x70V at the caps.

 

[Tekko]

Heres a CFP version if you can call it that with lateral outputs, in simulation offering 0.0005% THD at 1kHz at some 30 watts output which is about all i can do without exceeding the SOA of the output pairs:

http://i.imgur.com/aOhaz.png

 

[Tekko]

And a video: Jfet input Lateral mosfet output Power Amplifier - YouTube

 

[Tekko]

Oscillation issues solved: http://i.imgur.com/Lo3a7h.png

New video: Jfet input Lateral Mosfet output Power Amplifier - YouTube

 

[Tekko]

A board have been cadded for this thing: http://i.imgur.com/rq2Gq.png

 

[Tekko]

On this amp design, all on scope visible crossover distortion pretty much goes away with just 10-15mA of bias current per pair of output fets.

And i cant really hear any difference between 15mA and 75mA.

I find that rather unusual since most bjt designs wants atleast 20-30mA for the crossover distortion to even begin to disappear, and most mosfet designs needing 100+mA according to some.

 

[Tekko]

Some pics of the prototype, the second channel is under construction now.

Power stage:
http://i.imgur.com/u4der.jpg

Frontend and drive board:
http://i.imgur.com/ECvco.jpg

 

[Tekko]

Both channels built and ready for testing:

http://i.imgur.com/9S3bh.jpg
http://i.imgur.com/1aqvf.jpg
http://i.imgur.com/oNLM4.jpg

 

[Tekko]

And the prototype now in stereo is done: Jfet input Lateral mosfet output amp - YouTube

 

[U102324]

Personally I would not try and demonstrate an amp's sound by recording it with a cellular phone microphone and putting it on youtube. It sounds absolutely rubbish. Nobody would want something sounding like that.

 

[Tekko]

Its actually a real HD video camera with 48kbit sample rate, and there is no other way as my lappy does not have a line input, and the purpose of the vid was merely to show it working, not to demo audio quality.

But if you dont want one, just ignore any further posts from me.

And due to the zero interest and/or negative feedback on everything i've posted on this forum the past years, this could very well be the last project i ever post here.

 

[Tekko]

Due to negative feedback, this project is no longer available to this forum, and won't be until i either get atleast 10 apologies by pm or atleast a 1000 dollar compensation to my paypal account.

 

[PauloPT]

Don't you mean a million euros? 😀

 

[U102324]

Tekko, don't be so fu.,ing sensitive, I just made a comment regarding posting to Youtube. Maybe your amp sound fabulous, but the 48kbs HD video camera sound quality really sucks.