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Old 3rd May 2011, 01:24 PM   #11
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Perhaps a helpful link on cascode modulation(tm)!

The impact of the cascoded transistor in an Zenamp?

Interesting comment on affect of cascode on dynamics. Sadly we audiophiles are more like the fashion industry than we would like to be

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Old 3rd May 2011, 01:51 PM   #12
juma is offline juma  Serbia
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Cascoding is a simple matter too - the point is that JFET's Vds stays constant in spite of input and output signal variations. This constant Vds stops unwanted variations of parasitic capacitance (know as Miller effect) and the composite device (JFET + cascoding MOSFET) performs better than single JFET.
Off course there's more to it, but this is basic concept, easy to understand.
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Old 3rd May 2011, 02:41 PM   #13
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Ordered some LU1014's. Hope to build out to SUSY F3 starting with simpler iterations first. Still can't seem to think of advantages of paralleling both fets vs just the cascaded mosfets. Paralleled jFets would mean more gain, but may not be necessary.
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Old 3rd May 2011, 04:37 PM   #14
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look here Choky Susy F3 for LU1014's
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Old 3rd May 2011, 06:10 PM   #15
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Quote:
Originally Posted by Zen Mod View Post
Thank you Mr Mod, I have seen the thread, but hope to stumble through on my own in the hopes of learning something. I know his stuff is old news to you guys. The LU jfets are old news now that Pass' new SIT's are on the scene. Thanks for the help, I am sure I will need more.
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Old 3rd May 2011, 11:05 PM   #16
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Quote:
Originally Posted by Zen Mod View Post
One thing I remeber reading in the above thread was a very contentious argument between yourself and Magura about the benefit of a negative rail at lower voltage. His argument was that it was an unnecessary complication, whereas you eluded to the fact that it helped with noise. How does the addition of this rail help. CMRR is already high due to balanced inputs, how does the negative rail change or add to this benefit?
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Old 3rd May 2011, 11:17 PM   #17
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if nothing else - it include benefit of DC connection at inputs

in fact - Magura made something similar , finally

I can't remember is there dedicated thread for his amps ; that's the price when you're hanging with bunch of Off Topic maniacs
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Old 3rd May 2011, 11:32 PM   #18
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Your conversations can definitely resemble a haystack, but those needles are still there.
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Old 4th May 2011, 12:09 AM   #19
Zen Mod is offline Zen Mod  Serbia
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well - I can't remember that I said anything about benefits regarding noise , when including negative PSU ;

maybe I did ...... but what I know for sure that major benefit is deleting those input caps .

in any case - I didn't conduct any measuring comparisons between these two variants 0 wth/wo negative leg .

but - as you said - you're building your own haystack ......
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Old 4th May 2011, 01:27 AM   #20
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I would post pics of the inside of my AJ's, but doing so would provide visual eveidence of very real haystack possibilty.
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