kevin gilmore

another reason why many of the boards are on sockets is rework. If everything was on one board, and there was a problem, fixes could be tough. this way, one mini board does not work and cannot be fixed, it gets tossed.

joamat is doing the layout on this. all of the stax brain trust use the same software which makes things easier.

http://gilmore.chem.northwestern.edu/kgsshvcarbonright1.jpg ground plane on both sides, surface mount components on both sides.

he also did not address the temperature issues when you use a fixed reference. the reason to use a red led is that it exactly matches that of the transistor so the thermals don't cause runaway conditions. important because at 1kv, 1ma difference is a big deal. there is a way to bump up the impedance by adding one more transistor and another led in series. its also no surprise that the exstata and the idiot that designed it have no clue. for fun you can analyze the llmk1,llmk2,llmk3... given the high capacitance mosfets that replace the transistors, has to be really bad. schematics were posted.

its definitely my favorite amp for hd800 not even close. yep offset currents open input cause trouble.

well it might be ok if the water is 10**14 ohms... otherwise bad. do remember that someone dumped water on my T2 at CJ010 and it still lives 5 years later.

yep, wave a piece of paper over it, the thermals change and the offset drifts. for 18v rails, that is a good current.

someone please check these http://gilmore.chem.northwestern.edu/kgsshvcarbonv2.pdf http://gilmore.chem.northwestern.edu/kgsshvcarbon.jpg

this one, the servo is integral and required. Same as the T2

I like it.

I think if I design it carefully enough you can put 2 boards together, one is double layer, the other a single layer.

just tried it, very little actual ground plane due to all the wires. eventually when we go to all surface mount everything, the board will be at least 3 layers.

I was thinking those other resistors might be the plate resistors, but then what are the ones in between the caps. Anyway with the resistors not lifted off the board, the same thing will happen that has happened to the kingsound amps.

certainly can replace the reference with a to92, current datasheet does not list the pinouts. I did trim the emitter resistors to 25 ohms, so there is still about 9v on the servo. But will change values to the final parts when we all decide what those are. also added a pot in series with the 20k resistor to adjust the dc to exactly zero. the 25 ohms decreases the thd a significant amount at 20khz because of the added gain. let me know which parts and values to change.

no, just 2 transistors for the servo output drive. identical to Kerry's schematic. the final output is the Motorola part because its about 350mw and if you turn the current up, its more like .5 watt

latest version with correct resistor values for Kerry's servo http://gilmore.chem.northwestern.edu/kgsshvcarbon.jpg parts set for 16ma at 450v

i will start. very simple power supply, roughly same as original BH supply at lower power, zener based. definitely drifts with temperature. resistor based output tube. See JimL posts on current sources. And the resistors look like 100K which is extremely inadequate, but match the power level of the tube.

no difference between the 2sc parts and the pzta or mpsw or mpsa parts 1486 does not need heatsinking. About 188mw

50 years is the golden anniversary 55 years is ?? in 5 more years, 60 years is?? and this is what happens when you edit an edit of an edit of an edit...

its getting pretty tight... http://gilmore.chem.northwestern.edu/kgsshvcarbon.jpg laying the rest of them horizontal is going to be a bit of trouble.

but but Mikhail said that a 6sn7 and a we421 were identical. and 6j6a and 5844... And he consistently shoved all of them into the same socket to prove it. (with adapters) and god only knows how many other tubes. and 3d21 In place of 6ca7...

the version of the carbon board i am working on has pzta42,pzta06,pzta56 and at the moment mpsa06 and mpsa56 all of these parts are current fairchild production i have been told that all these parts have at least 5 years more life left. i have also been offered this really nice bridge in SF recently painted... the stn9360 lay down because they need to dissipate a bit more heat the pzta parts stick up vertically, and are therefore real easy to solder in. i have also added the cascode to the carbon. should be 100% mouser parts except for the lsk170/lsk389 which are easily available. with 20ma per leg, should make the current crazies happy. and 32 watts of heat per channel getting kerry's servo in there is going to be fun

the new verskon uses the bc parts

yep grounded gate.

you want a transformer that has 360vac windings you change the 440k resistors to 390k