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Old 10th September 2012, 09:41 AM   #1591
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There are other ways to lower Zo other than Rs size. We will see which sounds better to my deaf ear. Thanks StefanooI have 1K caps currently installed, but will play with that is well. I have never gotten the feeling that Nelson is terribly afraid of Ecaps in his amps and he seems to do OK with his designs. Myriad of choices or alternatives there, so it seems it is best to evaluate before assuming they are a problem. could always use self biased DM devices if it is really a concern. I think he is fancying those types these days anyway. I dont think Ilquam's experience with the amp is a good one to go buy. No slam on hime, as he did a phenominal job with his implementation, but his description is not what i would expect or what I have heard from transformer based designs using PP pentode tubes. That is what yo have here, in a sense. Minus the beautiful glow of course.
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Old 10th September 2012, 09:46 AM   #1592
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Old 10th September 2012, 09:56 AM   #1593
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Your having a nice laugh with your with your lunch. Enjoy! That amp by NEM you posted on other thread is very cool.
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Old 10th September 2012, 10:07 AM   #1594
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Want highest possible open-loop gain? Try this. Rs is only used for measuring bias current, not degeneration.
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Old 10th September 2012, 10:12 AM   #1595
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there are other ways to measure bias you don't need Rsource
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Old 10th September 2012, 10:18 AM   #1596
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Originally Posted by Zen Mod View Post
few volts , what else

gates - Pa sez that they're 10K-ish ....... so go figure
aha thats indeed low.

And what about proper loading the outputs; doesn't the spec sheet say 700 ohms or something near? A linear stereo potmeter could help to find the sweetspot.

It is just that I am worried about the 'fatique'. De Fatum.
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Old 10th September 2012, 10:20 AM   #1597
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Thanks StefanooI have 1K caps currently installed, but will play with that is well. I have never gotten the feeling that Nelson is terribly afraid of Ecaps in his amps and he seems to do OK with his designs.
Where is stefanoo?
Nelson loves Elna Silmic. He has stack of them in his B5
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Old 10th September 2012, 10:31 AM   #1598
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Originally Posted by lhquam View Post
Want highest possible open-loop gain? Try this. Rs is only used for measuring bias current, not degeneration.

that's exactly what Buzz is buzzing ,previously mentioning pot across Rs

he's listening now exactly what you drew

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Where is stefanoo?
Nelson loves Elna Silmic. He has stack of them in his B5
stay put ;

I'm enough of idiot for this thread

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Old 10th September 2012, 10:35 AM   #1599
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Originally Posted by triode_al View Post
aha thats indeed low.

And what about proper loading the outputs; doesn't the spec sheet say 700 ohms or something near? A linear stereo potmeter could help to find the sweetspot.

It is just that I am worried about the 'fatique'. De Fatum.
that issue is beaten to death in this thread , mostly by me

then Pa came with fact that this Jensen is completely happy as embraced , seeing gate (10K-ish) on one , and low Elna impedance,on other side

of course , proper loading for every xformer still stay as individual case
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Old 10th September 2012, 10:39 AM   #1600
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Want highest possible open-loop gain? Try this. Rs is only used for measuring bias current, not degeneration.
Neat. Flip side to your suggestion. Will it be possible to have only one current sensing resistor [for example 0.1 Ohms]; in series with the drain of the bottom JFET [drain to Out]; or in series with the drain of the upper JFET [drain to V+] ? The LEDs of the bias circuits have a negative temperature coefficient. Maybe glued to the heat sink to maintain a steady idle bias!
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