kevin gilmore Posted March 8, 2015 Report Share Posted March 8, 2015 (edited) so this has been kicking around for a while, decided to publish. take my ubaltobal converter, cut it in half, and then take the top piece, replace the input transistor with a tube... high impedance input... DC coupled, no negative feedback, less than .01% thd, 10db gain... just add a high power bipolar output buffer, and cheap tube hybrid with lots of plankton. work in progress http://gilmore.chem.northwestern.edu/tubehybrid.pdf 100 volt power supply real simple with TI TL783 high voltage regulator +/-30 supplies with lm317/lm337 with boosters cheap! Edited March 8, 2015 by kevin gilmore 1 Quote Link to comment Share on other sites More sharing options...
Earspeakers Posted March 8, 2015 Report Share Posted March 8, 2015 LM317 supplies, I love it! Quote Link to comment Share on other sites More sharing options...
Earspeakers Posted March 8, 2015 Report Share Posted March 8, 2015 (edited) How about a differential (EDIT and high gain) version as an input to a electrostatic output circuit? That is, a Megatron without the coupling capacitors. Coupling caps are evil, I use teflon and that costs a fortune for the megatron. Edited March 8, 2015 by Earspeakers Quote Link to comment Share on other sites More sharing options...
PretentiousFood Posted March 8, 2015 Report Share Posted March 8, 2015 Neat! The KSC3503 and KSA1381 might work better- they're current production complementary parts and good up to 300V, and the NPN has a much higher Hfe. Lots of good 200V parts too. Quote Link to comment Share on other sites More sharing options...
UFN Posted March 8, 2015 Report Share Posted March 8, 2015 Very interesting! //UFN Quote Link to comment Share on other sites More sharing options...
mypasswordis Posted March 8, 2015 Report Share Posted March 8, 2015 How about a differential (EDIT and high gain) version as an input to a electrostatic output circuit? That is, a Megatron without the coupling capacitors. Coupling caps are evil, I use teflon and that costs a fortune for the megatron. How about the SRX revisited? This also might be interesting: http://gilmore.chem.northwestern.edu/electra4.pdfThe circuit is easy enough to p2p and replace resistors with current sources. Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted March 8, 2015 Author Report Share Posted March 8, 2015 this circuit is ground referenced, so not suitable for megatron style stuff. Unfortunately, the only thing that works there is the T2 circuit, or something like it due to having to drive the output tube at -500V was not aware of the other Fairchild parts, definitely in this case better than the higher voltage parts. Really only need 200V parts Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted March 13, 2015 Author Report Share Posted March 13, 2015 board getting there http://gilmore.chem.northwestern.edu/tubehybrid.jpg Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted March 29, 2015 Author Report Share Posted March 29, 2015 (edited) since grindingthud seems to be faster at building and testing my stuff than I am... http://gilmore.chem.northwestern.edu/th.jpg http://gilmore.chem.northwestern.edu/thps.jpg http://gilmore.chem.northwestern.edu/boards/th.zip http://gilmore.chem.northwestern.edu/boards/thps.zip the big high voltage cap is actually 470uf 160v and the little cap is actually 33uf 160v they are right on the boards, wrong on the pictures schematic http://gilmore.chem.northwestern.edu/th.pdf Edited March 29, 2015 by kevin gilmore Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted July 29, 2015 Author Report Share Posted July 29, 2015 (edited) congo5 building and troubleshooting now. updated th.zip and thps.zip and th.jpg + and -15 flipped and -5 cap on amp board flipped all fixed. congo5 says its working now. one other thing, because of the tube, a warmup circuit or better, and output protector is required th2.zip has the output protector on the boards Edited August 2, 2015 by kevin gilmore Quote Link to comment Share on other sites More sharing options...
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