SOT: Attempt at "tubish" MOSFET amp

[Penguin]

just my two cents.  the marshall mosfets were actually quite good.  not100% by any means but they still had the feel of it cause you had to crank it to get it to respond right.

[mac]

jimbo.

Mosfets are quantum devices. It was Mr. Werner Heisenberg and his uncertainty principle dE = hdF what gave me that idea at first sight. Calculation involves deviations from the mean value, that's why I'll increase a priori the working voltage.
Anyway, the blurring effect could be imperceptible to our ears... I'll have to do the math.

If you don't see any reply soon is because I was terribly wrong  lol

mac

http://www.geocities.com/guitarfxs

[mac]

More on why high voltage supply... now in english (should be in spanish for me...)

I've been GOOGLEing and reading a lot of technical reasons why it is better to use high voltage supply on very specialized devices, among them a better freq response, although at values far away from the audio range. Others are a better hum-to-voltage ratio, more headroom, better slew rate, etc.

But I read a paper that may be used as a guide:

http://www.vtl.com/pages/whytubes.html

As I have to see it to believe it, I built a simple 2-stage preamp using BF245. First at 6V and then redisigned for 25V. Yeap, a very subtle improvement. Dont ask me why!

Hope an elect. eng. may throw some light here.

mac

http://www.geocities.com/guitarfxs

[Penguin]

the mosfet preamp i was working on was a high voltage tube style one. based off an article that pops up around here from time to time. i liked that. but i got stuck in a rut i ended up with three channels[keep in mind this is over 6mos ago and i havent' touched it since] the first channel was completely clean and it had ample headroom run in the 50+volt range.   i ran the medium gain channel [what i called the acdc channel] on 24v and i ran the ultra smack high gain channel on 6v or so.  i liked the sounds it produced but there was no dialing back the gain on the dist channel it was on full tilt. 

Clean Channel was Irf820 or 520 whatever came from fairchild as a sample pack.   and i used bs170's for the medium gain channel and high gain was originally the 170's but i opted for a different one. which i will have to dig up a no. on it. i haven'ttouched it since i blew the cheap tranny that was in there. i plan onbreaking it out and redoing it wheni move

[spudulike]

the mosfet preamp i was working on was a high voltage tube style one. based off an article that pops up around here from time to time. i liked that. but i got stuck in a rut i ended up with three channels[keep in mind this is over 6mos ago and i havent' touched it since] the first channel was completely clean and it had ample headroom run in the 50+volt range.   i ran the medium gain channel [what i called the acdc channel] on 24v and i ran the ultra smack high gain channel on 6v or so.  i liked the sounds it produced but there was no dialing back the gain on the dist channel it was on full tilt. 

Clean Channel was Irf820 or 520 whatever came from fairchild as a sample pack.   and i used bs170's for the medium gain channel and high gain was originally the 170's but i opted for a different one. which i will have to dig up a no. on it. i haven'ttouched it since i blew the cheap tranny that was in there. i plan onbreaking it out and redoing it wheni move

Want to share the schematic so far ? 

[jrc4558]

So? Has there been any recent developments in single-ended mosfet technology?

[Gus]

Some hints

Look at a PRS solid state amp.  I have one

Look the  the fender patents from the 70's there was a cool one IIRC using transistors.

Read R.G.'s Vox page

Now read all you can on pentodes and then how crazy the math gets with a pentode PP or SE and an output transformer and clipping.

look at the curves for triodes, BJTs and mosfets

Also read the "Art of Electronics" there is a circuit fragment in there.

I have a cool se mosfet circuit I built no big deal.

There is an older book "blackburg" series?  about mosfets and there is a 4 watt SE Mosfet amp circuit Late 70's book IIRC.  I think I have it somewhere in the house..