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Two triodes cascaded cathode follower?
Two triodes cascaded cathode follower?
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Old 16th September 2013, 11:15 AM   #1
dreamth is offline dreamth  Romania
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Default Two triodes cascaded cathode follower?

Is there anybody that made a 2 cathode followers in one stage after a cascode input stage?For the input of my first phono riaa preamp I built a cascode with two tubes(d3a and e288cc run at 20ma) and the output dc voltage at the top plate of the cascode is 220v dc so I want to place after it a cathode follower exactly like an inverted cascode and a ccs on the bottom so that the output dc voltage come to be like 110v dc for the following riaa filter.
I mean that after the first 2 triodes of a cascode I want to place a cathode follower that is a source for another bottom cathode follower and a ccs so it contains three triodes and that the output signal would be taken from the second cathode of a cascaded cathode follower.The commands for the top and for the bottom cathode follower is taken through a divided resistor network from the first cascode plate which ends in a bias 3v battery for the bottom ccs.
Is it a viable configuration that could lower the output impedance enough for a lcr riaa filter if I use 6n6p biased for 16ma as tubes for the cathode follower?I don't want to use transformers for lowering the cascode impedance and is somewhat impractical due to the 20ma dc current from the first stage.
The plate voltage for the cathode follower is 333v and with 3 triodes , 2 for the follower and one for the bottom ccs I could have a very low output impedance.
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Old 16th September 2013, 12:00 PM   #2
jazz is offline jazz  Netherlands
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Location: leiden, physically that is...

Take a look at Allen Wright's RTP3C. Not exactly what you're planning but it might give you an idea.

oh, what a beautifull day
I wanna go out and play!
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Old 16th September 2013, 12:01 PM   #3
Shoog is offline Shoog
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Aren't you describing the Aikido.

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Old 16th September 2013, 01:19 PM   #4
DF96 is offline DF96  England
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