Pass JFET Power Amplifier

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GRollins said:
..........
All this is just an elaborate way of reminding yourself to create simple circuits.

Grey


fashion is more elusive thing in fifi world;
it's even more dangerous in DIY crowd....

I was personally more than few times sooo disappointed ,when I manage to achieve something for long time awaited....
I remember when I finally purchased my first Thorens (318MkII....)-even with decent cartridge,adequate setup ,nice phono section-I didn't have that s p i r i t in my music......

even more embarassing was a fact that I lived several years with mother(s) of all TTs- EMT930.... (in local radio station)

which Thorens can compete with that?

youth ,and naivety.....

same with almost every other piece of fifi gadgetry-I payed my prices.....
now-I don't know better what I need to know; I know better what I don't know ,and I also know better how to enjoy in learning....


hey,Grey , are you a some sort of writer,judging by your passion for long posts,all without any electronical fact ?

( 😉 )
 
jacco vermeulen said:


Me thinks the home league is what makes all the difference between the Mad Sciencist and plain mad.
Reminds me of Peter Sellers as Mr. Gardiner in "Being There". :clown:

What's the verdict on Choky's Babbelfish ?


I prefer opening scene in "Party" ; most hysteric and craziest moment in all P. Sellers's films.......

regarding Choky's Babbelfish J-seems that already Devil's Advocate (GR) and Devil himself (Papa Nelson) makes verdicts.......


NP:
I didn't use the 1 nF lag compensation or compensation on
the npn in the current source, but I do recommend about 7 pF
across the 221K feedback resistor.


what else I can read between the lines ,except that Papa didn't have more objections


me-happy camper :clown:
 
You're assuming that I've had time to look over the schematic...not so. Any attempt to read something into a non-existant post is silly.
I'm afraid I didn't get the point of post #362. If is was meant to imply that simple circuits are somehow trendy, I suggest you look at the past century of simple tube circuits before making such a judgement. It's really the meaningless complexity of a lot of the solid state designs of the last thirty years or so that are the trend.
Or to put it in other words--just because you can do it doesn't mean that you should.

Grey
 
Sorry to change the subject, however I have a question about the PWR JFET Amp. I just received my LU1014Ds (thanks Grey) and was going over Mr. Pass's schematic. Please excuse my ignorance, but would it be possible to power the circuit with a +15VDC rail and a - 30 VDC rail,with some modifications,thus eliminating the output capacitors? ( I know.... I haven't even built the original circuit yet!)


Bruce 😀
 
Gray🙁first I want to say -thank you for your valuable input to my musings.......)
You're assuming that I've had time to look over the schematic...not so

OK 😉
Any attempt to read something into a non-existant post is silly.
?! non-existant?
I'm puzzled now..



I'm afraid I didn't get the point of post #362. If is was meant to imply that simple circuits are somehow trendy....

nope-that wasn't my intention; in fact -just contrary



It's really the meaningless complexity of a lot of the solid state designs of the last thirty years or so that are the trend

exactly what I meant in post 362;in fact- it's not just complexity or lack of it matter of fashion in DIY world; it's more issue of man's nature -that often trend is more valuable than personall evaluation and confidence in own judgment and knowledge...

English is still (just?) my (second) foreign language,and I didn't learn it in school;I learned Deutsche Sprach in school,but unfortunately,I forget 90% of it....even if I'm capable to read technical articles :xeye:

so-it's often possible that I simply can't be 100% clear in my scribings :clown:

voilla:
that's my last paper iteration of J Babbelfish-ing:

(feel free to comment :devilr: )
 

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Bruce,
I don't think I'd try it, unless by 'some modifications' you mean a servo or something to keep track of the DC offset. Variations in the bias from one pair of devices to the next could easily lead to enough DC to roast a speaker. For that matter, the bias will change as the circuit warms up.

Grey
 
GRollins said:
Bruce,
I don't think I'd try it, unless by 'some modifications' you mean a servo or something to keep track of the DC offset. Variations in the bias from one pair of devices to the next could easily lead to enough DC to roast a speaker. For that matter, the bias will change as the circuit warms up.

Grey


Thanks Grey. There is more to say about the dual rails, but that's for later. I just hope I see more from others about the Zv8/ JFET power amp. Unless, of course, I'm in the wrong thread! :bigeyes: :cannotbe:

Bruce
 
There are ways to handle the bias; to lock it down. If I can just get a little more time, I'll get an amp out that shows a simple way to do it. There are others. Getting a consistent bias current will go a long ways towards solving your DC offset problem.

Grey
 
Zoran said:
Hi
sorry for interruption...
What happening about the
ditributing Power JFETS ?
I did not receved any information for the
time
(and i could not find the link to topic of group bying ?)
Thanks


contact dhole (Dave):
http://www.diyaudio.com/forums/member.php?s=&action=getinfo&userid=20759
I think that he received already first batch from gray

anyway:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=71633


hehe
when you contact dhole ,please contact me ,too 😉
 
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