kevin gilmore

probably 100 ohm series resistor is good idea will add it to the board edit: changed 50 to 100

and that's the problem. the 4 pin is balanced only, no ground. can't be used on common ground headphones.

so far total length difference on the longest trace is .3 inches works out to about 100 picoseconds. if I was doing work in the 100mhz to 1ghz range, it would make a difference.

new feature for the freaks over there that don't like square corners... all board files with "m" at the end have mitred corners. I don't see the difference, but it only takes a few seconds to convert.

there is no functional difference in the new boards, just for people without the mpsw parts probably lots more surface mount updates on everything else soon. the idea is 100% mouser available parts

because I'm being picked on elsewhere for using obsolete components... surface mount versions of the dynahi in the boards directory. smt pzta56 and pzta06 replace mpsw06 mpsw56 ssdynahibalsmt.zip ssdynahibalsmth.zip second one is on board heatsinks

other than the fact that i don't have any. two versions of the 6ra6 board http://gilmore.chem.northwestern.edu/kgst6ra6.jpg http://gilmore.chem.northwestern.edu/kgst6ra6cascode.jpg and cascode version of 6s4 http://gilmore.chem.northwestern.edu/kgst6s4cascode.jpg someone please check for errors

anyone find a 6ra6 or 9ra6 datasheet in english, or at least can tell if the pins are bottom view or top view?

I can do a version of the board for 9ra6 if you want but an adapter should be easy, the plate and the filament are the same pins the cathode and the grid each move down a one pin

yep in fact you can delete a number of the parts. 2 sets of RCRC and then a jumper on the C to ground.

that is definitely my layout. wish i could make boards at home, i could waste even more time and make the house smell of ferric cloride.

you are supposed to use 1kv diodes!

a variac will make testing easier

i will see if i can cram 5 watt resistors in that place. re: q27,q28 probably better to put 1 watt transistors in there, trouble is finding them. Those transistors are rated at 500mw, and they are running at 436mw new board will take 5 watt resistors, these http://www.mouser.com/ProductDetail/Ohmite/WHE1R0FET/?qs=sGAEpiMZZMtlubZbdhIBIFwx82bjKdTOEgG%252bjKeDnyQ%3d but seriously, that power supply should not be able to supply more than 1 amp, so the 1 watt resistors should have been sufficient. will turn q27 and q28 into pzta56,pzta06 new board http://gilmore.chem.northwestern.edu/cfp2c.jpg and new board file in the boards directory thanks to grindingthud for doing this, my time is more limited these days, and I knew this amp was going to be amazingly good, and fairly cheap by the way, on my prototype I had to take it to someone to measure it, because its below the range on my equipment. Ends up .003% thd at 20khz at 40v peak to peak everything else like thd at 1khz is basically unmeasurable with even equipment in the $25k range. And its flat to more than 1mhz, the result of being a current amplifier.

I agree with all of those numbers, especially the gain.

oops, those should be 5k. The board says 5K now. maybe we can increase those. what is the voltage on pin 6 of the opamp to ground.

updated schematic

a metcal soldering iron with the big tip. still its not going to be easy.

the 2 resistors go to C2 on the original schematic. top of R30, bottom of R15 the resistors join and connect to pin 6 of the opamp like this http://gilmore.chem.northwestern.edu/cfp2f.jpg

integrators do not work that way, but try it synthesis says that flipping + and - definitely does not work. the pair of resistors, but they need to be 5k not 50k

shit, looks like the feedback is upside down again. my simulation software continues to do that. I thought i had it fixed, evidently not. same thing happened to the original squarewave clone. i am changing to new simulation software, probably today. huge learning curve, not happy. will check when i get home, i don't think i have that file here. better idea... remove r19 from the board. solder in 2 x 50k resistors on the bottom of the board from the opamp output pin to the top and bottom of the bias generator. Same as this. http://gilmore.chem.northwestern.edu/multiamp.pdf let me know...

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

its bipolar inputs, (one of my pure bipolar series) so there is input offset bias current. Input pot really should be 10k or 20k. very fast, very low noise, very low distortion.

thermal on pin 3 is definitely missing. will fix on the layout in a few minutes. pin 3 has to be connected to ground.

definitely ok on +/-20v