kevin gilmore

only if you stick them in backwards. (or if they are labeled backwards which I have seen) updated schematic... you gotta be kidding. probably this weekend. and then I am going to have to show how you calculate the trimmer resistors for other than 20v

unlikely it needs heatsinks, or just really small ones.

nope

that is exactly what I had in mind. except for the more basic units, no GR supply, and the rk50 replaced with a rk25 and its associated board. plenty of room for the transformer, xlr connectors and iec connector. the boards are 50th short on the width, so all the heatsink holes can be lined up end to end on .5 inch spacing. transistors on the bottom for the GR supplies, no problem, hanging in the air with the smallest of heatsinks also works. board layout for the rk50 board in the usual place.

you do have version 1.15 or later of the power supply board? the first version of the board had a 1khz noise problem that required adding a cap and resistor (x4) and I remember that knob

I have posted the goldenreference6 board, has options for center tap transformer, and dual windings for next time

the HV boards, the 3n254 is .15 spacing, and the board is .15 spacing any of the tiny 1 amp ones will work. on the LV board the spacing is .20, and its definitely a different bridge, the same one used in the ksa5 power supplies rated for 10A I think

this is a reasonably cheap version, probably a very good idea if you are doing T2's http://www.micromark.com/microlux-tapping-fixture,8363.html

the name of the game is to keep the tap completely perpendicular to the surface i got a super old tapping jig that does just that, so simple to use, and the 10 inch or so handle makes it easy to figure out how much torque to apply

i hate microsoft remotely administered computer requires an ok to change the kernel... (brilliant) fixed now. does not seem to happen very often

the angle brackets bolt to much bigger heatsinks, same way as T2 because the sicfets are bigger I am now using 1.5 x 1.0 inch aluminum angle bracket .125 thick

2 X 22 volts should be just fine, still need some heatsink on the pass transistors does not seem to be a standard value though

separate bias wires for each side, plus an antenna to detect arcing same as quad esl63's amplifier has much more voltage swing than hev90

1) 35V 581-TAP476M020CCS don't have a link for the 10uf 2) does not matter I used these 810-FK28C0G1H470J 3) I used these 505-MKS2-4.7/50/10 which are in stock and 50V, more than enough 4) I used these 505-MKS2.01/63/10

yes absolutely. If the outputs to the minus rail short out, then you are putting close to 900v on the diaphrams. Same as any other direct coupled electrostatic really we should have a protector for this. The 5.1k resistor is to prevent death to humans in case something bad happens. and as for the new sennheisier product, boy are some people over there delusional thinking its going to be only $15k.

10 ma for the driver is more than enough. needs to be 3 transformers, 2 of which have 4 windings of 380vac each the other is the kgsshv-carbon transformer

yep that is the idea over the weekend i replaced the 1.5k resistors with 2k original vishay resistors rated at .01% and 5 ppm voltages much more accurate. version 5 of the goldenreference board has a place for 1M pots that go in parallel with these resistors for those that just absolutely need to adjust to 6 places (actually those pots may influence overall thermal stability, cermet pots required)

1.25 volts 160 ma current draw on each rail at 20v

the circlotron is the only push pull fully direct coupled electrostatic amplifier that is buildable with current parts. Also at 25ma, rise and fall time are faster than any other electrostatic amplifier of any kind.

balanced in, balanced out, 7vrms out into 50 ohms 1khz goldenreference power supply at +20.0000, -20.0000 (hand trimmed resistors) thd is .011% which is actually the base line of this particular meter typically .003% on the quantasylum400 and less on the audio precision

a complete set of boards is 2 x output boards 2 x driver boards 4 x single hv900 power supply boards (or 2 duals which won't fit in a single box) 1 pair of fat power 450v supply boards (or the dual which also won't fit in the box)

the display is part number dd-52 and in the usa you can order at 800 833 9200

I just updated to what I think is the final board, I added a ground layer on the inside and flipped the relays on the top for uniform ground plane.

birgir got one from likely the same source, I bought one from a usa source. for sure they are all going to need new VF displays which are about $100 with shipping from Tektronix. The replacement of the display is not easy, many very fine traces, need the proper unsolder gun. that said, these are great for doing electrostatic measurements as they go higher in voltage than any other thing out there but have a low end limit of about .02%

#4 it is, new file posted v42 which is actually 4.2 but I'm lazy