John Curl's Blowtorch preamplifier part II

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How about 19 & 20KHz Results, as well 76 & 80Khz...?
Quite similar as THD 10kHz and quite according expectations and physical laws..Try it .
2 PMA
For the same input voltage, Vout without 1meg resistors is slightly higher , but all harmonics (to 7.) are lower in absolute magnitude,but of course not in ratio to e.g second harmonics.Same sim software, same models, same parts values.
 
2 PMA
For the same input voltage, Vout without 1meg resistors is slightly higher , but all harmonics (to 7.) are lower in absolute magnitude,but of course not in ratio to e.g second harmonics.Same sim software, same models, same parts values.

I have shown results for both same input voltage (yesterday/today) and output voltage (my last plots).

Our sim software programs are not completely same, there are distinctions.
 
Hi,

Quite similar as THD 10kHz and quite according expectations and physical laws..Try it .

Which sim are you using? Do you have a file you can post with models?

2 PMA For the same input voltage, Vout without 1meg resistors is slightly higher , but all harmonics (to 7.) are lower in absolute magnitude,but of course not in ratio to e.g second harmonics.Same sim software, same models, same parts values.

Well, one question, if all is exactly the same, why do you and Pavel show distinctly different results?

Ciao T
 
See, it is the Krill. Hint, start swapping models and then change the magnitude and phase of the load like a REAL speaker and watch the fuzz at HF move around. At least the Krill tweak actually removed the dominant thirds.

Krill!?

KrillFromAboveWater.jpg


I did not know they can have dominant thirds, but I guess everything is possible...

Ciao T
 
Hi,

You are repeatedly mentioning "the Krill".
Would you care to explain or point to a site that I can understand what you are talking about?

Krill - Wikipedia, the free encyclopedia

Krill is the common name given to the order Euphausiacea of shrimp-like marine crustaceans. Also known as euphausiids, these small invertebrates are found in all oceans of the world. The common name krill comes from the Norwegian word krill, meaning "young fry of fish",[1] which is also often attributed to other species of fish.

Not sure what this has to do with feedback or audio circuits though.

Ciao T
 
Thank you Thorsten. Well, I wonder too....

Hint: This site has a search feature. It isn't pretty. The Krill amp had a pot that caused foruitous cancellation of distortion at 0 phase of load current (if tuned with an 8 Ohm load). My OPINION of course.

Knowing that the dominant terms in capacitor nonlinearity are very low order, a circuit that does nothing to the second and third harmonics but does on the higher order ones would be strange indeed. Not even investigating the process is typical.

So as far as I'm concerned we have two bona fide sets of modern devices that produce opposite results so nothing is proven by simulation. We now have subjectivists blindly using simulation to proove a point, cool.
 
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Hi,

simple google search gives the real answer:

http://www.parttimeprojects.com/audio/diy/Krill.php
and
http://www.diyaudio.com/forums/solid-state/134619-krill-little-amp-might.html

But you knew that already didn't you thorsten ;)

Simple google gives me what I linked. There was nothing audio related in the first 100 results.

And no, I did not know this before, cute output stage, seems like one of the Japanese "non-switching class B" circuits from the 80's that resolutely refused to sound anything like like "Class A" despite claims of "Super CLass A" and the like written on their frontpanels.

I wonder if this did any better?

Ciao T
 
I have shown results for both same input voltage (yesterday/today) and output voltage (my last plots).

Our sim software programs are not completely same, there are distinctions.

PMA some simulators need settings to assure that there are no numerical roundoff generated harmonics. I showed a plot, double precision noise is -300dB. Without using these settings I can't get below -100dB or so with LOTS of false harmonics especially in the presence of a large fundamental.
 
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Hi,

Simple google gives me what I linked. There was nothing audio related in the first 100 results.

Ciao T

well I hadn't heard about the krill before either (I figured it was a play on the krell name) so my input into google was "krill amplifier" and the first two hits were the ones that I put into that post :)

So now that is out of the road, the discussion can get back to audio rather than crustaceans ;)

Tony.
 

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See, it is the Krill. Hint, start swapping models and then change the magnitude and phase of the load like a REAL speaker and watch the fuzz at HF move around. At least the Krill tweak actually removed the dominant thirds. Just watching now.

Hi Scott

Bringing back memories. :D

BTW: O has opened his blog site, you need to log in to see or contribute, send him an email to get a password.

Cheers
S
 
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