kevin gilmore

pretty close to production now.

first picture is baseline with 6db antenna 0 to 100mhz 10db/major division 10mhz per horizontal major division top line -30dbm 1 inch from power supply. second picture is with the 600v power supply turned on and into a 1meg ohm load. 3rd picture is hall probe on the input power supply line. so 200khz flyback switching frequency.

i did some quick tests and they are pretty quiet. but i plan on doing more exact tests. cap.inductor,cap should be more than enough. spec sheet seems to imply 20mhz which cant be right. will get out the spectrum analyzer to make sure.

all three power supplies a total of $80.62 with shipping from china. fully regulated 12v to 18v input. i could not build these things for that price, no way.

after all these years we have finally found a solution for the power supply modules at a rational price. which means we can make a transportable electrostatic amplifier. similar to srmxh,srm252,srm270 etc. 3 times the power, +/-400v power supplys, no obsolete components etc. designed to be mounted to the bottom as a heatsink with silicone thermal sheet in between. should be about $250 in parts unless you go nuts with the volume pot. not sure of casing yet.

so this is the way to do it correctly. its the only way not to seriously effect the thd. unfortunately both opamps have to take the voltages of the output devices. which means they have to be opa445 you set rv2 to the maximum amount of current. Then B1 is a 10k pot to V+ and ground. r11 is actually 100k.

if it works right then yeah.

would like to see what effect this has on thd. especially large voltage swings. still think an optoisolator drive to the vbe multiplier.

totally 100% safe. looks like about 100kva. proper personal protective equipment required. typically 600v if its to generate 3 phase. makes the stuff birgir is doing to e-cars look tame.

its all stax tube amp with mills style non-inductive plate resistors. thats basically all of them except for the t2.

suggest you solder all connections associated with the filaments. and then solder them again.

someone needs to post very high resolution images of front and back, then will correct schematic if necessary

suggest you redraw that part of the schematic that you think is wrong. there have been mistakes in stax schematics in the past. especially the t2. once it enters production and works...