FETs - interesting devices

bajaman · Post by **bajaman** » 18 Jul 2007, 07:36

Hi Folks
Here is some very interesting reading

members/archive/FETS/

offline:[/b][/u]
http://www.nutsvolts.com/~downloads/fetmay.pdf
http://www.nutsvolts.com/~downloads/fetjun.pdf
http://www.nutsvolts.com/~downloads/fetjul.pdf
http://www.nutsvolts.com/~downloads/fetaug.pdf

Enjoy
Steve

soulsonic · Post by **soulsonic** » 18 Jul 2007, 08:09

Yeah, good stuff. Anything to help me understand these damned FETs better is a big help to me.

Is it just me, or is a tube a million times easier to bias than a FET? Ive never had any problems getting tubes to do what I want. Even when I was completely ignorant of what was actually happening in a tube, I still didnt have any problems getting them to work. But with FETs, they are such a mess its unbelievable. I feel completely hopeless when Im trying to get one to work right the first time. I have gotten MOSFETs to work well, but I am always thinking, "why do I need all these extra resistors?". It just doesnt seem practical to me.

bajaman · Post by **bajaman** » 18 Jul 2007, 08:56

Hi soulsonic
I love tubes too.
You can run them off all sorts of voltages and get completely different sounding music.
Fets take a little bit more getting used too - and they are inherently noisier than the good old 12AX7 or ECC83 for our European friends

My personal favourite jfet is the 2SK117 - Roland/Boss use them (and so do Tech 21, I am led to believe, in their Sans Amp Classic pedal - much better sounding pedal than the GT2, which does not use one

)
I do hope you persevere though - practice makes perfect, as they say - hope you get some interesting new design ideas from these articles - I feel a BOOTEEK pedal design coming on

Cheers
Steve

soulsonic · Post by **soulsonic** » 18 Jul 2007, 09:23

Funny you should mention the 2SK117.... so far that's the JFET I've had the most success with.
I'm sure I'll get it down to where I'm as quick with it as I am with tubes, but I really wish it didn't require all the additional biasing stuff. With tubes, if you have the bias way off it just sounds bad - with a JFET or MOSFET, you get no sound at all!

bajaman · Post by **bajaman** » 18 Jul 2007, 10:26

That is the problem with 9 volt stuff - not much margin of error

Now with a tube running off 240 - 380 volts

Cheers
Steve

Post by **modman** » 06 Jan 2009, 01:43

Moved to the FAQ section, good excuse for a

Fuzzer · Post by **Fuzzer** » 06 Jan 2009, 02:41

But now the PDFs are gone.

bajaman · Post by **bajaman** » 06 Jan 2009, 10:37

(check first post for link)
enjoy

bajaman

Post by **modman** » 06 Jan 2009, 10:47

Fuzzer wrote:But now the PDFs are gone.

yeah, it was very late, I should have checked.

bajaman wrote:members/archive/FETS/
enjoy
bajaman

I hope this isn't a NZ based mag, will setup a central library folder or something later today.
thanks for saving

puppiesonacid · Post by **puppiesonacid** » 06 Jan 2009, 13:14

I hope this isn't a NZ based mag, will setup a central library folder or something later today.
thanks for saving[/quote]

that would be a great idea. I was bummed when i realized it was so long ago haha, I was thinking " okay, maybe I should try to learn some more today and clicked excitedly, to no avail...

Fuzzer · Post by **Fuzzer** » 06 Jan 2009, 14:20

Thank you very much guys, now I'm gonna get reading.