Jump to content

kevin gilmore

High Rollers
  • Posts

    7,124
  • Joined

  • Last visited

  • Days Won

    21

Everything posted by kevin gilmore

  1. Pretty sure the B24 also uses higher voltage power supply rails. At least +/-40 volts. The SE/balanced thing works out great on all the electrostatic amps because the closed loop gain is so high, 54 to 60 db. So if you measure the output voltages both ways, the difference is a small fraction of a db. Low loop gain things are much more trouble. This is why the kgitsojc circuit is specifically designed to match the gains in SE to balanced as well as balanced to balanced. Something the original never did because it was unbalanced input only. It is true that a lot of stuff out there has very poorly designed balanced outputs. krell,levinson and ayre do it right. The worst offender it seems were all of the balanced singlepower disasters. Ray did not do it right on the B52 either, although the A10 is supposed to be correct. Then there are the transformer based things that are labeled as balanced when in fact they have hugely different rise and fall slew rates. Fully differential fully complementary symmetry amps are the best. Unfortunately not possible in electrostatic amps unless you want to do serious transistor stacking.
  2. standard terminal blocks with .2 inch pin spacing on all connections to both the amp boards and the power supply boards. No pot on the production version.
  3. I've seen pictures of the original with 7308's and 6dj8's. I'm using 6dj8's. My experience with the russian tubes that say they are the same as something else usually is that they are not even close to the curves that are published for their tube let alone compared to the original. For ac coupled standard tube circuits, you would never tell the difference. For a fully dc coupled circuit with the top tube as a cathode i'm willing to bet that the russian tubes would pull positive grid current, and all sorts of bad would happen.
  4. tubes sure look like switches to me... UNIVAC 1101 - Wikipedia, the free encyclopedia 2700 tubes in fact. Each dual triode was a flip flop.
  5. See this is exactly the problem Mikhail created. Lets just throw any tube in there and watch what happens. I like mine the way it is. Tube rolling on this thing is probably a real bad idea.
  6. That sure scares me too. I have a batch that i know really came from hitachi with original hitachi packaging. Even when an input tube went nuts at CJ, all i did is pop a new tube in, all the bias's were fine, and kept going. I'm using NOS sylvania i think... But 50 year old tubes are a pain in the neck. I've never had a problem with the el-cheapo chinese output tubes either. Don't sound great, but don't die either.
  7. It is possible that current production 2sk216 parts don't have the protection zener built in... That could explain it. Not true, pin 9 is connected to ground on the component side of the board. Measure with an ohmmeter and you will see. Also the center shield pin on the socket is connected to ground.
  8. kevin gilmore

    ChiLiquiFi

    12/4 works for me. Subject to less than 4 inches of snow on the ground. Not going to bring any hardware. I think that bottle of tequilla looks very interesting. But i'll have a list of 4 just in case something isn't in stock when i get there. I think 3 bottles total should smash everyone Would not like to take half of it home like last time.
  9. The amp board is 11.950 x 16.000 The power supply board is 11.950 x 10.000 but the inside of the chassis should be exactly 12.00 inches wide. allows for .025 per side for irregularities due to warping of the heatsinks.
  10. Well the TEC at the time cost me $4500. Completely stainless steel guaranteed not to rust. They lied. The only way to send it back to the factory was to take it apart, because no standard shipping company would have taken it in one piece. And all the screws and a lot of the stainless was rusted pretty bad, so there was no way to take it apart. Went into the trash can. Only some of the parts had the 20 year warranty, so it would have likely come back with a $2k bill. Never again.
  11. I never did the parts kits. Never will either, not enough time. All current chassis are spoken for. There is actually one extra chassis, but no board set to go with it. I just don't see me doing another chassis run. Some other fool would have to take that on.
  12. Before i had the weber, i had a TEC. Way expensive. Was supposed to last 20 years. Firebox and ceramics cracked after 9 years, then i found out that they can't sell replacement parts because the ceramics were wrapped with an asbestos like compound and then inserted into the firebox. So even though it had a 20 year warranty i would have had to send the thing back somehow to the factory. That was not going to happen. Moral of the story, nothing lasts forever. If you don't run the thing at 11, it should last 10 to 15 years. But it is made of clay/ceramic/who knows what. And if you drop it, or if it falls over due to wind (kind of hard to do as its pretty damm heavy) it might break.
  13. My boss has one of these things, (the bigest size one) and absolutely loves the thing. I've had some food from it, and it sure is tasty. It can do things my gas fed weber cannot do.
  14. For those interested here are the prices. It really only makes sense if i do another 20 piece board run. power supply board quantity 5 $157 each quantity 10 $97 each quantity 20 $61 each amp board quantity 5 $242 each quantity 10 $166 each quantity 20 $102 each so prices did go up ever so slightly due to increase in sales tax. which makes a set of boards quantity 5 $399 quantity 10 $263 quantity 20 $163
  15. kevin gilmore

    ChiLiquiFi

    I like some of those pics. maybe an armagnac this time. The reason for binnys is that there is a store less than a mile from my house I like the 70 year old stuff too, but that is going to have to be for a very special occasion
  16. power supply fix pictures courtesy of Inu http://gilmore.chem.northwestern.edu/noise%20fix1.jpg http://gilmore.chem.northwestern.edu/noise%20fix2.jpg But if you don't want to cut the land, you can put the ref chip up on a pair of sockets with a resistor in the middle. Picture on that later.
  17. kevin gilmore

    ChiLiquiFi

    I should have said that the booze has to be at least 80 proof. And something interesting.
  18. And now i get from another distributor that the 2sa1968LS has been discontinued and i have to order from them NOW... This is getting real old real fast. Glad the board is designed for both. Was going to modify the power supply board for the 2sa1968ls because justin likes the led's... But...
  19. It may be a plastic package on that part, but its not insulated, collector is on the bottom.
  20. kevin gilmore

    ChiLiquiFi

    Consider arm broken. Still have lots of booze left... But i'm in the mood for something fancy too. Someone go to the binny's website and find something in the $400 to $500 range that is in stock. (a single bottle of something) Then let me know what to buy. Since all of the toys on my to buy list are still vaporware, i have to spend some money on something.
  21. There is a reasonable distributor, i think in england that ships worldwide and has reasonable prices. Don't remember which one, its buried in the T2 thread somewhere.
  22. updated bom. also this which is real sweet, but needs a slight bit more work and then some testing. The only shuntregulator i know of that won't blow up without a load. http://gilmore.chem.northwestern.edu/shuntregulator.pdf
  23. looks like about $350 in parts with the transformer. plus the circuit boards much better version of the bom, still missing the other parts of the thermal washers and part numbers for those http://gilmore.chem.northwestern.edu/kgsshvbomas.xlsx you would need to add input connectors and a pot. If someone wants to do a group buy on all the transistors, and someplace else other than the usual place, i'm sure we can get the price down somewhat.
  24. I want to see pictures of the insides first. I use OCXO's all the time, they are a $500 part. At least the good ones are that much. I don't see how you can put a $500 part inside a $3500 retail priced unit. Poorly done non PID temperature control would be just as bad as no temperature control whatsoever. Still, kind of silly as the only thing it does is stabilize at a specific frequency, and unless the thing is actually powered on all the time, it would do more harm than good. TCXO's are a much better idea, and cheaper and stabilize quicker. Analog volume control is definitely the right way to do this.
  25. Had not thought about that. Will have to look into it.
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.