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Showing most liked content since 05/28/2017 in all areas

  1. 17 likes
    Bought the lg 65 oled, will be here next week
  2. 15 likes
    I got the HV sections and bias up and they work perfectly Here's the board... I've already tested the GRLV boards and they work. I just have to build another set for this supply. The thermals above the IXCY10M90S regulators don't go above 99 deg. F. Very happy with the board so far.
  3. 14 likes
    Helped some friends go from this: to this
  4. 13 likes
    Another Grounded Grid lives. Have been listening to it for about a week. Powered by the same GRHV/GRLV PSU I use to power my KGSSHV, Carbon and Blue Hawaii. 400VDC rails and 20mA plate current. Using EH 6CA7 - the true beam tetrode not pentode. Runs much cooler than the Blue Hawaii. A tough job remains to drill the holes on the top plate. This is one fine sounding amp!
  5. 12 likes
    Well I've reflowed a bunch of joints (probably more than was needed). Since then I haven't had problems with oscillation, excessive offset, etc. The sporadic noise seems to have gone as well, but of course just as I say that it'll come back to spite me. Anyway, thanks for the help. I think I can stop fucking with it and just use it to listen to music.
  6. 12 likes
    Had a graduation party yesterday for Andrew, a good chunk of the family came. Karen and I had most of it catered, and the result was quite stress-free for us, allowing us to enjoy family. Also found out that my dad - 82 years old - just fully retired this past week from his dentistry practice! My dad and oldest brother Scott, and Andrew & me:
  7. 12 likes
    Fired up the vinyl rig after two years - damn I forgot just how great vinyl can be Sent from my iPhone using Tapatalk
  8. 12 likes
    Amidst all the frou frou decorating going on at Rancho Stretcho, some man plans are also being made.
  9. 11 likes
    Got the LV supplies done now. All good 😊
  10. 11 likes
    Marched in the Knoxville pride parade with my family and some local libertarians.
  11. 11 likes
    Hmmm I don't think I removed the loop out on any of ones I've done. Pop the hood and I'd know... In other news, as the SR-Omega owners know all to well...there are no more replacement earpads and the old ones are pretty much awful. Any set with the stock ones will be mimicking a block of wood by now and the replacements Stax used to sell were pretty fucked as they were just wrong. First of all they were black and then the dimensions were also wrong. They are all gone now as well so what to do... Well take a crusty set of earpads and re-engineer some new ones with the company that is making the earpads for my headphone project. Now they are real leather with memory foam. They are also thicker as they are much softer and the opening was made smaller to control the bass issues if the SR-Omega. Now this is the just the first prototype but what an utter fucking pain in the ass to install. I've sourced the pins Stax used and I'll order some new mounting rings for the next batch but yeah, not easy to install. Something I'm not sure can be changed but we'll see. Here they are mounted to the headphones: Yup, the "old" earpads are new old stock but mine won't last forever. Now how does it sound...bloody brilliant and they are so much more comfortable. Some more listening to be done on my part but some of my issues with the SR-Omega have been greatly diminished.
  12. 11 likes
    Ugliest build.... Aluminum sheets from e-bay.
  13. 10 likes
    Look! Top plate, 1.6 mm copper clad single sided. I do think we have copper polish somewhere in the house…
  14. 10 likes
  15. 10 likes
    I published a modification for the Stax SRM-T1/T1S/006 in AudioXpress July 2017, which is just out. The modification adds 5.1 kilohm output safety resistors and cascoded constant current output loads, which with their heatsink fits the space vacated by the plate resistors - see photo. Spritzer did something similar a few years ago with an SRM-007, adding constant current loads, but he also changed to 6S4A outputs. Unlike plate resistors, constant current loads burn up practically no signal current, so while the stock amp burns up 9.2 mA signal current in the plate and feedback resistors at its specified 300 VRMS maximum output, the modified amplifier only uses 2.8 mA driving the feedback resistors, leaving much more current available to drive the headphones. Since the output tubes are much less stressed, distortion is decreased and 2 dB of extra headroom gained. The modified amp circuit is very similar to a KGST or KGDT. This is no accident, as the KGST was designed to be “a Stax SRM-007t with no cost or retail considerations,” and the 007t is a higher power T1. The modification lacks the KGST’s regulated power supply, but larger power supply caps have been fitted. Since the amplifier is fully differential pure class A with current sources or loads at every stage, the current draw is pretty constant, minimizing power supply effects. The modified T1 can drive demanding headphones like the SR-007 Mk I, something that the stock design strains to do. The relatively flabby bass, somewhat dark tonality and soft treble are largely eliminated. Replacing all the old electrolytic power supply caps should also be done as routine maintenance. Parts cost for the modification is about $35, so total parts cost is around $100. With T1 amplifiers going for $400-$700, this is the best bang for the buck, a good starter project for someone wanting to get into electrostatic amp DIY without going to a full build.
  16. 10 likes
    Went out for a quick spin on the MTB today on the trails behind my house. A neighbor pointed me to a new section, which is a hoot. Good news is that the test of the 1x10 conversion that I had done last week went without a hitch.
  17. 10 likes
    A great anecdote in the paper about Douglas Bader, the double-amputee English WWII fighter ace.
  18. 9 likes
    Fuck it. This. Is. HEAD-CASE! Maxxed out it is.
  19. 9 likes
    It was actually very easy to rebuild the large T2 with the DC/DC converters. Used same daughter board layout as for as for my modified T2, only had to move one hole 50th. I also have plenty of space since I only use one and not three output transistors and I found some nice spots for the daughter boards. One channel has the DC/DC converters and the other the newly made 01N100D/LT1021 boards. Both channels seem to work OK. Below: Daughter boards with LT1021 and 01N100D on heat sink. Boards with DC/DC converters and LT3045. Now it's late, done for today.
  20. 8 likes
    This weekend, but won our block's first game of the Finnish game Mölkky!
  21. 8 likes
  22. 8 likes
    I set up a phone interview for a job I badly want, for next Wednesday. University IT director position, 5 minute commute, excellent pay and benefits. and for once it's a job where people on my reference list are known quantities, and respected ones. I applied Tuesday, so it seems that they are moving fairly quickly.
  23. 8 likes
    Like the fact that I can both not run and not bike on it. Definitely a value multiplier.
  24. 8 likes
    Some progress. The terrible unbalance was due to an unconnected small tube pin. During the milling process the CNC machine drilled a couple of unauthorized holes which I completely forgot when soldering the board. When corrected the amplifier works. The offset is done by opto servo and it works as supposed. Balance control is also done by servo and I've no trimmer. I've same balance servo here as in my amplifiers with LSK389 input and there it works without any problem. With the tube input you can probably expect more differences between the sides. First tube I tried gave 260 V unbalance (offset worked, so +130V and -130V) and the second tube gave 30V unbalance. The balance servo (in current version) is not capable to make it balanced if the tube isn't enough matched. The input is supplied by +100V/-15 and all components there are surface mounted. Current source is 01N100D/LT1021. GG to the left and tube input GG to the right.
  25. 8 likes
    Did this today. "Twin holes" along the right side of board - forgot to mirror before drilling the board, but this is a prototype and it will probably blow up anyhow…
  26. 8 likes
    Never mind the wiring rats' nest for now, it's making music! The problem I was having with one channel, worked out to be a cold solder joint on the global NFB resistor network on one tube. Was distorting the voltage (off by 10V) on its pzta56/lsk389 half and throwing the balance and offset WAY off. Once found and corrected, both channels are stable as a rock (while running 30 minutes) without the servo engaged. Under 1 volt balance and offset both channels. First listened with my SR-207 then my SR-009 (with a lousy iPhone 6 Plus as source). Using 2000 vintage SED Winged C EL34s at 20mA. Damn, this amp kicks major ass! Now time to mount the transformers, clean up the wiring and build the umbilical, wire up the bi-color power switch, replace the 12V zeners with 18V ones, get the RK50 somehow mounted in to the case, and button it all up. Will post glamour shots when done. Thank you Kevin for such an incredible 'stat amp. I'm really going to love this over my KGST.
  27. 8 likes
    Turning an old capacitive terminal keyboard from 1978 into a modern USB keyboard with fully programmable keys. Got it working fine, but had to tear it back down for keycap polishing and a few minor tweaks. Currently reapplying dielectric lube to all the key stems. Need to finish up this project so I get back to testing Circlotron stuff.
  28. 8 likes
    Got my boards today. Thank You! I have posted pics before but here are some more of my build. I noticed these boards have a 12 V for the filaments. The old board did not have it.
  29. 8 likes
    Had a brief respite from man's inhumanity to man by taking a walk among the giant Sequoia's in Calaveras Big Tree State Park.
  30. 8 likes
    So I've installed a 10pf bypass cap. At first the value for offset was way high (like 400V give or take) but after adjusting the batteries it fell back to within normal values. The T2 has been on for at least 5 hours now, and it hasn't misbehaved in that time. I've had to go back and check after hearing some puffs of noise which turned out to be in the recording itself. At the risk of jinxing it, that seems to have worked.
  31. 7 likes
    Food Truck Cajun food. Sent from my iPhone using Tapatalk
  32. 7 likes
  33. 7 likes
    Put on the shim and FSA seatpost. Now this bike rides as nicely as I remember the DeSalvo rolling. Shaved a few ounces off from the tree trunk of the seat post I took off as well. Somehow managed to shave 8 seconds off my PR on my neighborhood climb so those few ounces must have been some really heavy ounces. Sent from my iPhone using Tapatalk
  34. 7 likes
    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
  35. 7 likes
    Just did 5.5 miles in the woods, 500 ft of climbing. Heart rate basically never dropped below 150. Felt like I was going to die most of the ride, but I did it, so next time should be easier. Made a friend
  36. 7 likes
    Today I’ve equipped my modified T2 with the 01N100D/LT1021 current source Kerry has simulated, see previous posts. From beginning it had a straight 10M90S set to 10 mA. When JimL came with the cascaded version I removed the two resistors at 10M90S and added a small board with the DN2540 and corresponding resistors(red circle below). Today I made new daughter boards containing LT1021, 1k resistor and 47pF cheremic capacitor (green circle). Have listen to this for an hour. It works and I’m satisfied. Thanks Kerry for coming up with this. Below solar cell. Only for experimental purpose.
  37. 7 likes
    A SMD Dynalo. It is a modular double monophonic one, comprises four small PCBs: two for audio and two for the corresponding power supply.
  38. 7 likes
    Stickered up. Car gained 5hp. Edit: I wanted to do "MWIA Racing: Sleeping with the sponsor" but the kids ask too many darn questions.
  39. 6 likes
    The only snake I don't like is the Orange Deceptor, but they're found only in DC.
  40. 6 likes
    Really can't capture how nice the linen dial looks in photos. The 5740C is a pretty great movement, very accurate & the smoothness of the seconds hand is nice. Got the strap hand made since I wanted grey with round-scale alligator lining.
  41. 6 likes
    Met John (jvlgato) for lunch today, down by the VA. Great as always to see him, and had a nice chat (and lunch)! We'll have to do it again!
  42. 6 likes
    Lowered the resistor value at OP27 output. Now both offset and balance are in the mV area. Very happy with the outcome.
  43. 6 likes
    Celebrated Father's Day with my parents in the blazing inferno. The car said 114 and may have been more accurate. I can see Stretch getting in a whole heap of trouble up here on a regular basis real soon.
  44. 6 likes
    A few more pics of the Grounded Grid with the top cover on, including a side-by-side with the Blue Hawaii built using the same chassis. Got a set of tube socket rings coming. Will decide if to use them when I have them in hand. Drilled a few more holes on both the top and bottom plate of the Blue Hawaii to help ventilation inside the chassis and hope it'll run cooler. Will likely do the same for the GG.
  45. 6 likes
    I built this yesterday. There's some noise that I need to track down, but otherwise it seems to work. The offset adjusts to within a few volts using the balance pot; the offset pot doesn't seem to do much. Offset drifts a bit and I'm not sure I'm adjusting it right. Is there some way to disable the servo?
  46. 6 likes
    i also went to tokyo recently, and the used record shopping was even better then i had hoped for! so many shops everywhere! well stocked, organized and best of all, properly graded! surprisingly, i didn't find much (old) japanese music though, which was a shame, as i really wanted some Taeko Ohnuki records (i already have them on cd, but i want vinyl too!) i also bought a AT33 mono, as it was so cheap down there.
  47. 6 likes
    Welcome @Cattler! Welcome to head-case. Hope everything is chill with you. Do you meditate regularly? I think its pretty cool to do so. I look forward to it now. For a fun and easy tex-mex meal, cut up some chicken breast into cubes and saute in the pan with salt and pepper. They'll cook quick. Then cut up an avocado or two, add salsa and tortilla chips of your choice and VOILA, you have a tasty and reasonably healthy dinner. Works great for leftovers except for avocados which turn into a goddamn horror show 20 minutes after you cut them open. What is the deal with that? @Cattler lets get to work on an avocado that stays good for longer. Thanks for your time.
  48. 6 likes
    Missed Al's post. If you want to do typing, get the 12" Macbook. Super light and small with a real keyboard plus fast enough for anything I need to do on the road! I use it all the time at work and in coffee shops and never need anything faster. The keyboard takes time getting used to but I actually prefer it now. Ordered a new iMac 27", 4.2GHz quad-core Intel Core i7, 32GB RAM, Radeon Pro 580 with 8GB of VRAM, and 512GB SSD (for those times when I need something a bit faster than the Macbook). Also, got the new ipad pro in the mail today. Excited to open it up.
  49. 6 likes
    The plan was to grill a ham steak and some veggies. I did the prep and went out back to light the grill. Then I noticed that a skunk was sharing my back yard with me. He came waddling towards me. That was enough for me. I ceded the back yard to the skunk, put the prepped food in the fridge and microwaved something. The skunk dined on a fallen avocado. Both of us did OK.
  50. 6 likes
    Afternoon Tea, in Columbia, CA @ There was Tea Apricot Scone with Strawberry Jam and Cream Sandwiches And to finish, Chocolate Torte Because Joanne got to enjoy some Port Tasting in Murphys, I was allowed some Raspberry Sorbet and Blackcurrant Ice Cream