F4 power amplifier

[mpmarino]

- I was trying to get the exact layout CVILLER came up with, but was having no luck with Eagle , now I have to choose one to use (what a good problem to have)

Yes! Same here! (are you looking over my shoulder ?) I've already chosen which one to use - the one that's done .

[GRollins]

Originally posted by steenoe
1: Dont turn on the telly, ever Its the single most annoying and disturbing thing, and should be forbidden by law! I mean it. I only look at it, when I put a Blues-film on the DVD player.
Rule number 2: Dont let the sofa jump on your back, when you get home from work! If you let it, you are a lazy ###, fill in the dots as you please
Thats two simple rules to get you going, and finish stuff! Its as simple as that

Steen

I turned off my TV roughly thirty years ago. I've watched it twice since then--when the Challenger exploded, and during the first Gulf War. I will watch a DVD of a movie, but that's not even a weekly event at this point, much less daily.
I never seem to have enough time to get things done, but if I was sitting in front of a television, I wouldn't get anything done at all. As it is, I've been tied up with a couple of plumbing related problems and other fun stuff, but have managed a few useful (in the sense of electronics) things.
For one thing, I have managed to get my hands on a large quantity of J271s. Hot diggity dawg!

Grey

P.S.: I've probably said it before, but I'm always amazed by the number of people who will respond to my comments that there aren't enough hours in a day with, "Oh, I know just what you mean! I never seem to get anything done, either." Invariably followed by, "Did you see CSI [or whatever show is 'hot' this week] last night? I just can't believe what John [pick random character name] said when Elaine asked him..."
Oh, how I wish I had some way to access all those wasted hours that others seem not to want or care about.

[jacco vermeulen]

Actually, i just exchanged the TV set and put it on the audio channel.

(do miss the RC sometimes and on ocassion scratch my head why i've got a house filled with idle big screen TVs)

[Magura]

Originally posted by steenoe
Thats why we teamed up If you want to finish something; here is rule number 1: Dont turn on the telly, ever Its the single most annoying and disturbing thing, and should be forbidden by law! I mean it. I only look at it, when I put a Blues-film on the DVD player.
Rule number 2: Dont let the sofa jump on your back, when you get home from work! If you let it, you are a lazy ###, fill in the dots as you please
Thats two simple rules to get you going, and finish stuff! Its as simple as that

Steen

It's really about as simple as that

Lots of people ask how I manage to find the time....very simple, no watching telly.

I actually don't even have a telly.
From time to time somebody thinks that this poor guy whom has no telly....should have one as a gift.

The result of that is that no matter how poor you might be, if you know me- you got a telly, as they are handed on to the first person I see whom wants it

I simply can't understand how people find the time for the average 3 or 4 hours of TV every single day. It would stress me out!

Magura

[steenoe]

Carawu's comic strip, say's it all Its a total waste of your life, starring into that totally empty screen. Most people cant even remember what they were trying to see the day before.
Build yourself one of Mr. Pass's amps and put on a good album, like the one Blues mentioned. You will remember that event for a long time If it wasnt for the other (beautyful) part of the household, the TV would go right out the window
If you want to see the grass grow, then at least do it under the blue sky!

Steen

[doggy]

I have some 2sk369 fets left over from a phono stage project; can I use these for the input buffer and if so which other compliment fet can be used with it?
Thanks

[Nelson Pass]

2sj109's are the go-to if you can find them.

[EUVL]

I have a somewhat theoretical question.

In US Patent 4168471, Sampei (Hitachi) described a stability criterion for oscillations between parallel FETs, and derived a equation for the minimum gate stopper resistance.

Applying his formular, I derived at a minimum R of some 800 ohm for the gate stoppers, using datasheet information and the F4 configuration as published (see attched Excel sheet).

My question would be, why could we get away with much less and are still stable with some margin ?
Did I do my sums wrong, or is Sampei's formular too conservative ?


Thanks in advance and best regards,
Patrick

[mlloyd1]

thanks for the pointer to that patent.

i haven't read it yet, but i will.
just curious, could sampeii's equations be designed strictly for (hitachi) lateral mosfets? (therefore, less accurate for hexfets?)

just guessing ...
may have more ideas after i actually read the patent.

mlloyd1

[EUVL]

The laws of Physics are the same in Japan or elsewhere.
Please read it first.


Patrick