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OTL Asylum OTL, Output Transformerless Amplifier User Group. |
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In Reply to: RE: (New?) OTL candidate scheme posted by Lew on April 10, 2008 at 10:07:04:
Dear Lew,
Thank you for your valuable advice.
According to my calculations (and my previous experience) the driver voltage swing (6SN7 output) should be of the order of 150V (+75/-75), that is, enough to get 0V on the 6080 tube grids.
The calculated small signal open loop gain (RL=8Ohm) is 50*14*6.5mA/V*4tubes*8Ohm=145.6.
Provided that DC output offset is sufficiently stable and low (less than 50 mV and I hope future tests will confirm this assumption) I hope to get the theoretical closed loop gain of about 21.
As far as the coupling caps are concerned, in order to get rid of a couple of them, I suppose I should add one more HV tension (350 V or the like) and I would rather to stick to the original idea of using a simplified power supply. I will keep you informed about the progress of this project as I have just finished the PS section and, as soon as I get the ordered tubes, I am going to start final integration and test.
Best Regards
Luca Cellai
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Follow Ups
- RE: (New?) OTL candidate scheme - cellai@space.it 23:57:51 04/10/08 (0)
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