[sdiy] Mosfet Amps?

[Magnus Danielson]

On 07/11/2011 03:57 AM, dan snazelle wrote:
> I think those might be issues if i was trying to design an audiophile system (this is the problem I have with David self...the same author who basically calls OTA's a historical curiosity, he is great if you are looking to build HI-END low noise power amps, etc but for guitar boosters, weird distortion boxes, etc Mosfets are great! ( i think the circuits I have been able to build with one MOSFET blow any one BJT circuit out of the water for a
> clean hi-gain device.
>
> I just want to get more info on them, instead of switching parts out randomly.
>
>
>
> I have been wanting to buy the book you are speaking of, but it is not cheap ( i can get most electronics books used for around 1-5 dollars on amazon if i wait long enough)
>
> so to answer your question, I am trying to make some hi-gain boxes for guitar and synth.

If that is what you aim for rather than power-amps then starting off 
with The art of electronics should get you in the right direction. Using 
MOSFETs is not wildly different from any other FET and to some degree 
even BJTs, it is just _different_.

What FETs excell at is high impedence compared to their BJT friends.

Stringing up op-amps as for current sounces and rig current-mirrors 
could be useful to get a MOSFET amplifier pair.

"Analysis and Design of Analog Integrated Circuits" should be a valuable 
resource even when you do not design ICs yourself. Many tips and tricks 
can be used regardless.

When you have sufficient of design concepts and decent descriptions of 
them you can combine them up into something useful.

Cheers,
Magnus