Inductor Loading Adventures

[Magura]

Originally posted by flg



Hmmm. Well, Ive had it running with the sig gen and the scope mostly with unmatched parts. I've listened to it on some cheapy spk'rs a little. but it had to low of an output cap for descent low freqs. Let me show you a pic of what it's set-up like for todays playing around...
The 120mH is a Hammond 195T5 5A 100mH Choke (measures 120mH @ 3.5A)
I'm going to look at the Open Loop Gain and Freq Response today and then add the R1 & R2 and see what I can get for Closed Loop response and gain...

I thought this better get a life of it's own

This looks a lot like what I've been playing around with lately, though I've found it to be ok with massive heatsinking and just one cascode, as opposed to the two you have i parallel.

I used a 4.700uF E-cap and a 50uF film cap at the output. A 80mH inductor, and 40V rails.

I got a flat response curve down to 20Hz, below 20Hz it starts rolling off, but nothing worth mentioning.

Magura

[Zen Mod]

?

edit:
just forget...... I found where it coming from ......

[flg]

Originally posted by Magura



I thought this better get a life of it's own

Magura

Sure, thanks. The low Freq problem I was speaking about is not really rolling off though. I start to see rolloff @ 30Hz and it's -3db about 6Hz(with Sine Waves). It's a "tilt" appearance to the squarewave @ low freq??? I was thinking it was to small an output cap??? You can begin to see saturation looking curvature to the squarewave at about 50Hz. But, this "tilt" bis gradually gets worse starting at maybe 1kHz??? By the time you get down to 10Hz, it's pretty much a sawtooth looking wave! I'm begining to think it's an inductor related phenomina??? I don't see it at the source resistors, only at the output...

[apassgear]

Who knows what this thread is about... It's a split from another one?

Can a moderator do something about this?

[Magura]

It most likely is an inductor related issue, cause I have seen nothing of it. I use an air core inductor with a DCR of (as I recall) 2.4R.

With a 120mH inductor, you should not experience this sort of problem.


Magura

[Magura]

Originally posted by apassgear
Who knows what this thread is about... It's a split from another one?

I started a new thread to not pollute the original thread, which is about a cascoded BOZ:

Jfet Cascoded BOZ

There is no connection between the two threads.

This thread is about an inductor loaded ZV9 style amp.

Magura

[flg]

Originally posted by apassgear
Who knows what this thread is about... It's a split from another one?

Can a moderator do something about this?

apassgear, pardon us It's about a variation on the ZV8/ZV9 theme as can be seen in the 1st post. Basically substituting light bulbs or aleph CS with inductors.
I suppose a Mod could if they wanted to???

[apassgear]

Great... thank guys

[SY]

Give me a descriptive title and I (or the next mod who sees this) will change it.

[Magura]

Originally posted by Magura
It most likely is an inductor related issue, cause I have seen nothing of it. I use an air core inductor with a DCR of (as I recall) 2.4R.

With a 120mH inductor, you should not experience this sort of problem.


Magura

FLG,

Did you see this post ?


Magura