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kevin gilmore

High Rollers
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Everything posted by kevin gilmore

  1. q19 and q21 are in all stax amps. limits the voltage of that particular section, they never trigger, and I eliminated them a long time ago. q27 and q30 are used as temperature matched diodes. same as Q8 which is mounted on the heatsink the 300k resistors result in a voltage gain of 1k (actually a bit more) when combined with r38,r39. carbon does the same thing with lower resistances they use stacked ksa1156, a pair of 400v parts. I use the stn9360 which is a single 600v part. there is no reason to do this in solid state front end amp because the 100v is 15v main power supplys are not regulated. and the servo jumps all over the place when the air conditioning kicks in.
  2. simplified schematic just updated, I got the current sources flipped. when put in the test position, it puts fixed resistors to the plates of the tubes to -15 so then you adjust the main offset and differential. then move back to the on position and further adjust the servo pots. when working right, keeps the outputs to less than 100mv. but range is very tight.
  3. I was listening to it while taking pictures... multitasking absolutely, don't want any metal nuts floating around in bad places 2 of the screws that hold the bottom plate on have very long screws and nuts, both were loose, and one is almost impossible to get to without taking off the front panel.
  4. power jumper block cleaned of all the epoxy j1,j3,j4 for 100v remove all others j2 j3 j5 for 120v remove all others j5,j6 for 240v remove all others and servo board pictures, unnecessarily complex tube rollers are going to have a lot of trouble with this, the servo has a pretty limited range, and the Russian similar's definitely will not work
  5. here you go, a whole bunch of resistors are the wrong values, when I have time Power supplies are 350v t8000schem.PDF
  6. next to the transformer is 7815,7915 which makes +/-15 to the slot and also the servo board filaments are DC HV is unregulated Cap,100 ohm resistor,Cap servo pretty much identical to the T2 servo the 15k resistors are something else
  7. I have your birthday present
  8. 2sc6127 for the outputs and the voltage gain stage, resistors, for pull up on the voltage gain stage, darlington output need better picture of servo, so that one later, stacked ksa1156 for the tube drive, the rest of it is a modern 717 with available parts. wiring, 100v J1,J3,J4 120v J2,J3,J5
  9. its birgir's birthday today, the big 35! so... special security screws on the top, 6 sided ultra miniature metric spline, apple tools work power conversion relatively easy once you get rid of the goop
  10. suggest you build the kgsshv-carbon first. do it as 2 chassis leave extra room in the power supply for a filament transformer and extra pins in the connector then you can build the GG as a second amplifier and use the existing power supply then even later you can upgrade the GG to DHT tubes simple
  11. definitely not. srm727 output stage running at 5 to 6 ma, and tube front end. but we will have schematics soon.
  12. in other news I have a tracking number now, so the t8000 is on its way
  13. work in progress hangs off the side with thin angle bracket, no drilling of holes
  14. 5V thru a resistor or 12V driving the cpc1117N opto coupler so after 30 seconds you apply a voltage, delay timer 555 or similar, same as T2
  15. the resistor marked open, put 100k there and see if it makes any difference. but with all tube amps, you really need a delay on the high voltage, most of the current high voltage boards have a switch, but you need a delay board to drive them.
  16. no feedback and a voltage gain between 500 and 1000 yep that is going to work, for at least 15 minutes till the tubes drift.
  17. a bit more current to bring the plate voltage down a bit
  18. noise level due to input tubes?
  19. That resistor was for lowering the gain when using the original opamp and a pair of diodes. will add a jumper once the board is verified
  20. happy it works. now for a version with tubes as the constant current sources And a cherub has just informed me a t8000 is headed my way I like retirement. going to a hamfest tomorrow to see what I can find to update some of my very antique test gear
  21. Short in the transformer to ground, seen it before
  22. looks fine to me, the oven door is no more than 2 inches in front of the cabinet faces. The previous oven which was a built in was probably 1 inch in front of the cabinet face all the heat goes up the back splash and under the feet of the oven out the front. favorite place of the dogs when the oven is on.
  23. yep, and requires 60 amp circuit 220v
  24. Before I got the Wolf oven/cooktop, I used a single burner cheap thing. Worked great. make sure you try a magnet on the pans you plan on using, some kinds of stainless pans are non magnetic and will not work. also they use 80% of the power of a typical kitchen circuit, so you can't use most other things at the same time
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