L Loaded ZV9 Help???

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An L Loaded ZV9, Why Not :D I just have this thing (DIY Thing) about not doing it exactly like N.P. does his thing. I like the L Loaded idea. Not to take away from Carpenter and his lead on ZV7-T and such, He seems to be taking it on and propagating that idea, etc... But, I really like the "idea" of the power JFET and the inductor loading. Very "Tube Like" :bigeyes: and such. I just figured that last year, I was working on an LH (PLH) and the Christmas music was fine... But it didn't work out as good as I would have hoped??? I need to get another proto working for Christmas music this year??? Why Not???
So, to that end, I'm putting together a ZV9 Gain stage on a big heatsink. I'll post a pic when I figure out I how I did that last. But, Just an LU1014D, with 2 IRFP240's cascoding it, and the load 1/2 above it. I would eventually want that to be a big L thing. And, I have a few. But, I might start with a light bulb or two, ala ZV8, but, waht do ya think???
Thanks... Gotta go cook for the parental units...
 
O.K. something like this :smash:
 

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carpenter, are you trying to confuse me :confused: There will be a real small amount of current necessary for the gate to feel like it's GND'ed. It will get it through the feedback R and the 100 ohm to GND, just like the pics you posted(47 ohms). And, speaking of the pics you posted :confused: This is an SE amp not a big diff SOZ like your having fun with ;)
It is something between ZV8 with an Inductor & ZV9 - the Aleph. I'd like to try to get a little more Iq out of it than ZV9, and a little more linearity and effeciency than ZV8. The 2 cascode transistors are due to an eventuall expectation of close to a 37 Volt rail once things seem to work O.K.
So what's that 1000uF doin in there :confused:
FaLaLaLaLaa LaLa La La :D
 
There will be a real small amount of current necessary for the gate to feel like it's GND'ed. It will get it through the feedback R and the 100 ohm to GND, just like the pics you posted(47 ohms).

I'm so glad to read this. I think it means that I don't need the extra resistor to ground at the gates of my buffers in my ZV7-T?

Thanks for the enlightenment!:D

John

btw, that big ol' cap is me copying Nelson's F1 (or was it the F2?)
 
Hi jack away dude. I wish I had a good answer for your ZV7-T with a buffer. The reason I don't is cuase I thought about that already a few months ago in the GSOZ-T thread I started and it becomes difficult to use feedback with the output at an absolute value of 23V or somethinig... You are then not really using the ZV4 buffer in the spirit it was originally used?
If I wasn't so busy with the "parental units" and my own ZEN variant, I might have some answers or ideas...
In your case, you have a voltage divider to ground from the output, in addition to the feedback requirement. A cap in the feedback line might be an answer but, that could also be a problem??? I need a cap in my output also but, a really big one... Gotta go for now...
 
I solved the problem. At least, I think I did. I'll post a little schematic on my little ZV7-T thread describing pictorially what transpired.

Long story short, I doubled the resistor value from the output. It was 221k, now it's 442K. What a difference! I could actually turn down the gain knob on my electronic X-over. Happy days!

Thanks for thinking of me, flg.

John:)
 
Well, it works :D :D :D I lit up my prototype ZV9 with an inductor load tonight :smash: Worked great! I'll post a pic of what I built with the exact values below. Except for the inductor. I really have no idea what it is:confused: Well, I have some idea I suppose. It's just that from all the reading I've been doing, and experimentation by others, and myself, I just figured what the hey, I'll just use the biggest thing I got up here. Especially if I have two of 'em. The inductor is actually an AC power Xfmr for 115VAC 60Hz input. Gotta weigh in at a good 15-20 lbs. The laminated core is 3" W x 4.5" H x 5.25" L. The secondaries are open. The Rdc measured about .2 ohms and it dosent even get warm at 2.5 Amps...
Some initial voltage measurements are on the pic. In addition, the -3db on the low end is about 10Hz! And, it's nice and flat up to at least 10K. It's starting to clip(on the positive side) at about 13.5 Vrms into my 7.5 ohm load resistor.
:D :D :D
 

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I just had to try another Load. I plugged in an Avel 800VA Toriod in the 115V connection. I guess that would be rated at about 7 Amps rms. I believe I previously measured this thing at about 275mH of inductance :bigeyes: I was still running the Iq at 2-2.5A.
So :smash: it did not look as good :confused: Square waves seem to tell some kinda story here... The square waves have an overshoot worse than the laminated xfmr :confused: or at least at the same freq. This response seems to worsen at lower frquencies compared to the laminated guy. The -3db seemed to be more like 80Hz with much more extreme peaks on the rising edges... Hmmmm... Saturation :confused:
The high frequency response seemed to maintain a better looking square wave higher though. Also the -3db at the high end seemed to be more like 100KHz.
Now it would be interesting to try an air core device... Hmmm
:smash: :smash: :smash:
 
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