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kevin gilmore

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Everything posted by kevin gilmore

  1. Now that would be cheating NO??? Besides which the person that makes that "other" tube amp would argue it is completely different when it is actually 95% the same This is pretty much the last time i'm going to ask that particular person to send me the electrostatic portable transformer he has promised to send me for over 6 months now. After that a whole bunch of schematics and pictures may just have to appear
  2. Jason was wrong. Before the final upgrade the 27gb5's were the active top current sources The 2 sections of each of the 6cg7 were in parallel and were the output gain stage tubes. The 6h30's were doing absolutely nothing usefull !!!!! (If you haven't figured it out by now, I have the schematic!) After the upgrade (i'm guessing here) The 2 sections of the 6bz7's are in parallel and 2 of them form an input stage differential amplifier. Same as the input stage of the B52. So you can supply balanced input, or unbalanced input. And then everything else is the same.
  3. Open offer still stands. You send me a dozen of the same tubes. You label them in any way you want that will not rub off. I will randomly cryo half of them. I'll send them all back. You try and tell the difference. Your choice of 2 days at liquid nitrogen temperatures, (77 degrees kelvin) or if you really want, 2 days at liquid helium temperatures (4 degrees kelvin) No charge for the cryogens or use of the dewars. Students at northwestern university can verify that i actually did this. So far no one wants to take me up on the challenge...
  4. The 6bz7's are most certainly in the input section, and not any part of the output section. There are large output tubes for the active current sources and other tubes with paralleled sections as the output amplification element. Don't remember the exact tube compliment at the moment. Similar in design to another tube amplifier well liked around these parts. Also remember that this is a balanced amplifier.
  5. alrighty then, major spoilers below * The fleet realizes the Cylons are somehow following it to Earth. * Tigh talks to Six about it, but their conversation (thanks to Six
  6. Nothing wrong with that. Nothing right with that either. Two boxes instead of one. Two sets of batteries instead of one. Two volume controls instead of one. Twice the physical size for absolutely no apparent gain. Have a happy new year.
  7. the interconnect cable is of insufficient diameter the amp chip in the ipod and in the tomahawk are in fact one in the same. Notice how few views for a post that has been around 18 hours. I really think that ray should get into the trendy $100 per inch cable business. Happy holidays. Certainly the best for me in a great many years, although i can't say why yet
  8. spark plug wires? That is so last century. Everything performance related these days is single coil over spark plug per cylinder.
  9. I told mikhail almost 3 years ago now to produce an amp like this. Better late than never. Earl: you forgot the 6336. and probably a couple of others.
  10. Billy, if spending $4500 on a preamp makes you sick, you are gonna be sick a whole lot in the future. In 10 years when you look back on the $150k you have spent on audio you will probably have a heart atack. Lets not even discuss cars...
  11. Kevin's review of the B52 from the pictures ray has posted. THE GOOD The aestetics of this unit are very nice. Still way to many ray samuels logo's and the logo's are way to big. But i happen to like the looks of the thing. KG's rating---- A- The quality of assembly, the quality of the parts, the quality of the layout. Outstanding. A particular company north of the border should look at how things are supposed to be done. KG's rating---- A At least the box is finally big enough so the electrolytics won't burn up due to the heat. Still a few more holes in the main board would definitely help. THE BAD Circuitry description. Differential amplifier on the input. Turns unbalanced signals into balanced or amplifies balanced signals. Output capacitively coupled to the 4 channel dact step attenuator. Output of the attenuator goes two places, one is the cathode follower preamp output stage, and the other is the balanced srpp headphone amplifier stage. KG's rating ---- C- Yes in fact as far as a headphone amp is concerned its 2 raptors in one box. As a preamp it has a cathode follower output stage, so it actually really behaves like as a preamp. Output impedance of about 2k is far better than the 100k impedance of the stealth. I feel sorry for all those stuck with stealth's which are now completely worthless. Yes the headphone stage is TWO SRPP stages in series with TWO output capacitors in series with the headphone. Double the output impedance. Double the slush bucket bass into low impedance headphones. THE UGLY What is this thing. A preamp?? If so where is the remote control. A Headphone amp?? Where is the low output impedance. Instead of doing one thing right, it does two things wrong. First thing if you really are going to use it as a preamp, chuck the 2 x 12au7 preamp output tubes and replace with 6n1p (after dealing with the filament voltage issue). But really with the same number of tubes and deleting the headphone output it would be easy to design a new board that fits into the same chassis and turns the thing into a conrad johnson clone. Plenty of room now for composite triodes. FOR A FEW PENNIES MORE ray could have actually added 2 wires into the power supply cable and avoided contaminating the high voltage ground with the grunge produced by the ultra cheapo fillament switchers. The B52 really is the best thing by far that ray has ever done. Stereophile should eat the thing up.
  12. Aerius please pay attention. That tube is completely and utterly useless for otl audio applications. Look at the Rp. Look at the fact that the sweet spot is 2500 volts and about 500ma. Decent output caps for that thing would be about the size of a gallon of milk. EACH.
  13. Rayvistors, right you are. I still can't find any of the boxes... But here is a new one. JVC's brand new 1080p 3 chip dila projector is called the "RS1" about $10k list, 8k street. I'm on the list for one sometime in early february.
  14. Yes i have designed one. The wj211 tube last time i checked was about $8900 each. You need 2. 4 for balanced.
  15. yes i believe in some current production tubes. Unfortunately virtually none of them are usable for audio unless you are completely nuts. Eimac (now independent again) makes wonderful ceramic triodes and tetrodes. The new western electric makes some pretty good 300B's. Way better than any other chinese junk, but still not as good as the originals. Hammamatsu makes some truely amazing products. In fact they make an amplifier tube so linear (and 50 ohm output) that works great as a headphone amp tube. Trouble is they are about $650 each. You need 2, and they would last virtually forever. Watkins-Johnson makes some very nice stuff too. They also make a 50 ohm output ultra low noise amplifier tube. You don't want to know the price.
  16. I agree with number 4. There are however tons of tungsol NOS 6080's available.
  17. I believe they were called hornets. I have a few somewhere.
  18. Actually it is still up. I figured someone would have taken it down by now. The people at the kindercare next door were all cheering my sign. I thought the area i live in was died in the wool redneck republicans, but maybe not.
  19. I put this up yesterday afternoon. http://gilmore.chem.northwestern.edu/impeach.jpg
  20. Could it be that adding a tube preamp with a high output impedance driving solid state monoblocks with whatever cables were used significantly changed the frequency response and what you think you were hearing was actually a change in tonal balance?? Fact is that there really is only one tube otl preamp out there with an output impedance less than 200 ohms. And its not cheap.
  21. billy i have found the perfect iem's for you to go with your new tomahawk... http://www.audiocubes.com/product/Elecom_EHP-AIN30_Rhinestone-Studded_Heart_Eardrops.html
  22. I dunno billy, there are so many better REAL tube/solid state balanced preamps available Here are three Audio research LS17 all tubes $3995 BAT VK30 all tubes $2995 Pass Labs X2.5 solid state $3990 All of which have a low output impedance and are actually capable of driving cables and power amps.
  23. The head-fi ray samuels marketing machine will be there to help ray sell the b52's. That and i bet stereophile will just eat the thing up. Then again, maybe not. As a preamp its output impedance is going to be way to high. A CJ-ART it isn't. I estimate 50k ohms. quoting conrad johnson "Even high-conductance triode tubes (such as the 6DJ8 and 6922) would normally have too high an output impedance. The traditional solution is to add a buffer stage (cathode follower) to the circuit. What we have done instead is to construct a composite triode made of several sections of 6922. Each doubling of the number of sections reduces the output impedance by a factor of two. The ART uses 10 sections... the Premier 17LS uses 4. In the case of the 17LS, the resulting output impedance is about 800 ohms." Yet i expect it to be priced more than the 17ls... No remote control, no input switching... As a headphone amp it is 2 raptors in series. What's worse than one raptor And the tomahawk, how many people will buy that piece of shit and not pay attention to the fact that it won't drive regular headphones and want to send it back. And as far as krell, ray's thing is definitely a slap in the face of real gear. I'm planning on a fork lift upgrade coming in february as soon as i can get a firm delivery on the new jvc HD projector with 10k:1 CR. Then a new krell preamp and a pair of krell monoblocks. All my current krell is now 7 years old...
  24. And while i'm at it... 5 wires between the amp and power supply chassis. only ONE shared ground wire between 2 asychronous switching supplies that are guaranteed to sing to each other and 2 x 250 volt high voltage supplies. One of the main ideas with a balanced unit with dual mono power supplies is seperated grounds... ?
  25. Someone just pointed this out to me... On the power supply, male pins with 250 volts DC on them. Ray had better fix that before someone dies...
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