kevin gilmore

i think i have a bare board, will look later

it better say 2k on both sides, but it might look like 5k flipped yet it sets the gain

so i'm not sure that is what you want because then the minus supply is completely unregulated which is the problem when you try to split the ground with only one regulated power supply. in effect it shorts out the 2 x 365k resistors. http://gilmore.chem.northwestern.edu/srxshunt3.zip has a position to short the unreg ground and regulated ground.

you don't want the tube sockets all the way in otherwise they are too low for the chassis.

pretty sure the goldenreference.pdf is the latest version

so I wire mine for balanced input only, all 4 wires go to the pot, and then when I need unbalanced I use unbalanced to balanced adapters which short rca ground to ground and xlr -

updated volumecontroller.zip http://gilmore.chem.northwestern.edu/volumecontroller.zip

sure seems to be very similar to thunderbirds...

power supply makes a big difference

don't see any ac25 in that picture depending on which supply, some are dual 25v windings, some are 25v center tapped

finishing a project with a kintex-7 now so yeah whatever one has more than enough horsepower and compatible with the xilinx compiler. the totaldac uses 74hc574, so yeah not so good either. if someone with the fpga tools wants to do that part, fine by me. I definitely want a dsd to 192/24 thing inside.

The soekris board is a perfect example of fucked up. Lvc595 chips where the 0 and 1 can be 60 mv different between drivers on the same chip let alone matching to the next chip. Then the crap 4v references. So when you test for missing codes and equivalent of stuck bits, major issues. Then the drift with temperature. Super expensive stuff (MSB) that use data general series cmos switches not much better. Hand picked discrete fets with hand picked clamps are superior. And discrete. And you will be stuffing parts forever. no tubes. The reason should be obvious

never tested fully. but probably base drive current may not be enough for 2+ amps

goldenreference is only good for about 1.5 amps when you need a lot more than that, you have to add an extra set of pass transistors. like the ones on the uber2amp board. And they have to be mounted to a large heatsink

latest code from Kerry works with current Arduino compiler, but still does not have the code for the flipped relays http://gilmore.chem.northwestern.edu/volumecontroller.zip

hinges with torsion springs just like the old thorens dust covers.

you need the specialized high voltage transistor tester. which do not seem to be on ebay at the moment.

a1968 has the cutouts between the pins, so could be real. no cutouts, definitely fakes. although the ones from dalbani had the cutouts and were definitely fakes. still a good idea to use a tester first.

Hook the 2 primaries in series, and test the output. If it's wired correctly you get voltage, if you get virtually zero, they are wired out of phase. It won't hurt the transformer. Don't do this for parallel windings

in the power supply they are running at only 400v and much less current.

buy the voltage tester from ebay and test them. Over 1000 volts, they are real, 230 volts and they are a massive pile of fakes from dalbani.

Parts sourcing is always fun. This has happened to me several times

bugs bunny: Oops i had the silly thing in reverse

reminds me of mikhail hand picking el34 that would work with 400v on the cathode. And the people involved remember how that turned out. kt66 has to go boom eventually and take the j79 and k216 with it.

the golden reference power supply setup for +/-40V