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Old 11th June 2011, 02:16 PM   #1
Stee is offline Stee  Italy
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Default the Perfect preamplifier jfet

this project have a common base VAS
important to avoid base saturation
and perfect feedback timing
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Old 11th June 2011, 02:54 PM   #2
DF96 is offline DF96  England
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I guess a perfect preamplifier in a perfect world can manage without any gate bias for its input JFETs!
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Old 11th June 2011, 03:47 PM   #3
Stee is offline Stee  Italy
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Default YES

need non-inverted input to GND
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Old 11th June 2011, 04:56 PM   #4
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+100mA through the 110R's at 25V rails will be interesting.
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Old 11th June 2011, 04:59 PM   #5
lineup is offline lineup  Sweden
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Input impedance is very low: 1K
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Old 11th June 2011, 05:05 PM   #6
Stee is offline Stee  Italy
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Default yes 5mA

if your CD player does not accept load around 1k you can use the non-inverting input
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Old 11th June 2011, 05:32 PM   #7
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Can any other jfet instead of those J74, and K170 not difficult to find, work well in this circuit?
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Old 11th June 2011, 05:32 PM   #8
pergo is offline pergo  Italy
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mmh, it works?
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Old 11th June 2011, 05:50 PM   #9
Stee is offline Stee  Italy
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Default i think

that comes from famous discrete op-amp that i have
but i'm not able to simulate
you do?
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Old 11th June 2011, 07:24 PM   #10
Stee is offline Stee  Italy
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Default see this solution

for phase correction and input inpedence
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