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Showing content with the highest reputation on 12/20/2020 in all areas

  1. Finally finished the box I made to put the wife's present in. Really happy with it. The handle is a detail I love. It's a cream leather amplifier handle I got for cheap off Amazon, but it feels amazing.
    11 points
  2. I am/was the moderator for the Tape Project forum and I have a modified Technics RS1500 with a custom tube output that replaces the 70's era solid state amp. I use that for listening to a collection of about 400 reel to reel tapes. I also have an Ampex ATR700 which is one of the last machines that Ampex sold. It was a collaboration between Ampex and Teac. I have a couple of head-blocks for the Ampex and I did some experimenting with the mono/full track head set processing tracks similar to what you're planning. The results were mixed, but in the long run, I ended up using tape machine plugins. I admit that my mixing chops weren't nearly what they should have been to make an honest assessment of the process but reel to reel tape is not the cheapest or quickest media to deal with and I'm pretty happy with the subtle results I get with the plugins I use. After running the Tape Project forum, I did get practiced at teaching and guiding other folks on the care and feeding of reel to reel tape machines. I wrote a guide which (although many links to pictures are now dead) still exists and may help you getting your Revox running. I'm a huge fan of these machines so I'd be happy to give you any advice you might need. Just PM me! Here's a link to the forum. The Beginners Guide is located at the top of the General Discussion page. https://forum.tapeproject.com/ Here's a pic of my listening machine.
    4 points
  3. My Makita track saw has a simple little anti-tip device when doing bevel cuts that works pretty well. Certainly works well enough for me.
    3 points
  4. 3 points
  5. A guy on /r/audiophile had a pair of 18" subs for a live PA that he was unable to sell, so he added them to his home theatre. WAF is quite low as it turns out.
    3 points
  6. Sunday breakfast... Scrambled eggs, bacon, hashbrowns, grits, biscuits & Earl Gray. This should carry me through to dinner time!
    2 points
  7. Someone generously shared with me a bootleg of the first Porcupine Tree show I ever went. I’m in heaven.
    2 points
  8. Well, unless I find some way to make some Purple Heart wood filler for my screw-ups, I think I am about sanded 80-120-180-220 and ready to wipe on some of this Arm-R-Seal stuff. Need better attention to detail, a better way to estimate angles for the trim and probably to do more accurate 45 cuts as the track saw likes to lean. Trying to force the floor and four sides together on dominoes was not a perfect experience either, I need an apprentice. I also need to write less on the wood, pain to get it all off. Good enough for mid-century modern dog toys I guess.
    2 points
  9. If anyone needs me, I will be flying to SA, renting a stepladder, returning it, renting a BIGGER stepladder, smacking 'stretch one, and flying home. (Not really.)
    2 points
  10. So I've been active on Flickr on and off since 2005. I used to regularly submit images to the Tattooed Girls group. Said group has been rudderless for what feels like a decade. All of the admins have been MIA for ages. In the interim, the group has been overrun with off topic images, porn, spam, images with phishing links in the description, etc etc. After several months of back and forth, I managed to get control of the group by contacting Flickr staff. The first thing I did was ban a few spam accounts. Since then I have been slowly going through the 65,000+ (ya rly) images and removing ones that don't fit. I'm currently on page 217 of 629, which is from some time in 2012. I've saved a few photos that I liked as I've waded through oh so many. I'm gonna post some here over the next period of time. Fair warning, there may be an occasional titty.
    2 points
  11. I posted a Chinese version of this article several months ago and now I translated it and put it here. I guess some people here will be interested. I hope you like it. Actually I have some more articles like this pending but I just don't have the time to write it up. --------------------------------------------------------------------------------------------------------------------------------- It all started about a year ago that a second hand sr-omega popped up in the local community. From time to time omegas show up on markets around the world but this one is different: an omega with 007 drivers installed. When the drivers are replaced, such omega drops its value to a fraction of its original. The seller listed it for 48888 RMB initially and sold it for like 20000 + at the end. When I first saw the listing, the first thing that caught my attention are neither the price nor the 007 drivers but one accessory laying aside, which is a pair of dead drivers I have never seen before. At first sight I know that it’s a prototype, a true unicorn that probably only one pair exists in the world. I am so curious on how it sounds and how it compares to 007 or 009 or the original omega. I messaged the seller right away and after some persuasion and explanation that I can give this driver a next life, I got it at a reasonable price. And it has become one of my biggest regret that I didn’t also purchase the omega itself that time, otherwise I can put it back into the place where the drivers belong to. Here is the driver itself. From this driver you can see several innovations made by Stax that has never been seen in other Stax models before it. The diaphragm is identical to a normal omega but the electrode is totally a different creature: copper plate similar to lambda sig etc. but much more refined. Over different regions of the electrode the thickness is different. The thicker copper comprises of the # pattern skeleton to give the rigidity while the thinner copper is perforated. You can see the same topology on 009 and 009s where they claim to have the MLER welding technology employed on the electrode. But this omega prototype electrode is in one piece and just as thick as a credit card. Furthermore, they rounded the edge of the perforation like what Stax does on 009S. Stax even make a sectional view illustration graph on their 009S promotion leaflet. Such treatment helps sound to radiate. To me it’s really impressive to see some characteristics of a flagship model today on a 30-year-old design. I wonder what the R&D department has been doing in these years But afterall it’s a prototype. It does have some problems: this electrode is too thin to give enough rigidity and prevent bending. They are curved to 5 o at most. Moreover, the area of attachment between the frame and the electrode is too small. It just peels due to aging. I see such defects in some modern designs too. Although its reasonable to have these issues because its 20+ years old, it does reveal that the one who designed it is not thoughtful enough. Perhaps that’s why it was never released to the market except the one on my desk. Besides the defects the design has, the driver itself is at a very bad condition. The drivers have been exposed to the external environment, so dust gets onto everywhere. The one who does not properly seal the package probably has never imagined that this driver will be repaired. It’s a pain in the ass to make the driver dust free again, especially when they are on the very fragile diaphragm. Normally I don’t accept requests to repair an exposed driver and I will give a new quote to clients who send me an exposed e-stat without telling me in advance . But I own this driver and I can bear the risk so that’s OK. The four electrodes are bent in different direction and magnitude as well as having detachment and failure of epoxy. Taking it apart and bent it manually is the only way out. It takes a lot of skill to bend a bent copper plate. Like you have to apply a certain amount of force on the copper and then you check how you have bent it by eye balling or a ruler, and you repeat this process a dozen times on one plate. You make it worse if you don’t know how. The most challenging part of it is that how much you bend an electrode actually affects the sound pressure on one side of the driver so at this point you just have to guess. I have neither the tool nor the file of the design, its all hiding in somewhere inside Stax’s archive library. At most of the time repairing a e-stat is more challenging and troublesome than making a new one. Aging will just make everything a mess and sometime you have to wipe the ass of someone who does not make the design good enough to withstand usage. Solvent removes dust and grease on the driver. It gets much trickier when it comes to cleaning the diaphragm. Effectiveness of a method to clean the diaphragm is an issue when there is just too much dust, not to mention the risk that you will break a diaphragm by puncture or sketch. At the end I decided to clean the diaphragm with solution. Although it will damage the coating, it means nothing to me as I can recoat it anyway to replace the old one which is probably damaged anyway. Cleaning done. They took away the dust screens so I have to prepare these as well. Last Step: assembly, the most important part of all steps. This several hours of work determines how long a driver can last before imbalance or noise occurs. Its my duty to make sure every edge and surface inside the driver is dust free. If not, dust will eventually get onto the diaphragm at some point in its service life and short the electrode and the diaphragm. Practically if the pollutant is much smaller than DS gap 0.5mm then its fine. All these procedures are done in a dust free environment. Soldering work Omega adopted a spring mechanism to connect the bias supply to the diaphragm. It is shaped like a tuning fork and it is odd (photo credits to audiohobby .pl ). I tried to make one but it just can’t grip firmly. After some days of having this troubling me I figured out a way, using HD600’s spring and I glad that it worked, at least for now. I used 007 cable, lambda sig headband, cnc machined and anodized aluminum casing and tailor made earpad. I am a proud Omega owner and I shipped the earpad for a clone. The result is satisfactory. I took away the back grill for inspection but I am kind of regret because I cannot put it back. The general sound signature of this omega prototype is somewhat identical to the original: natural, airy, transparent and clean. Its free of unnaturalness which can be found on 009 (please forgive me if you find this statement irritating, afterall the perception of sound is subjective). It has a larger soundstage than 009 for sure but I think 009 has more details than this one slightly. To me this prototype takes a midway approach between early-SN omega and Late-SN omega. It has a bit of the sweet coloration of an early omega while having much of the naturalness of a late omega. I found that early omega has a huge, diffused soundstage while a late omega has some in head effect which is unpleasant to me. Luckily this prototype is more on the early side. But still this prototype is different from the two regrading the proportion of width and depth of soundstage. I can’t explain more because I haven’t AB compare yet. What amaze me the most is how the prototype omega differs from the typical omega in the dynamic and bass region. The normal omega gives me an image of mellow, soft and relaxing in the bass region. Although 009 and 007 has better bass and impact I like the stress-free presentation of the original omega. The only thing omega put stress on me while I am wearing it is its price. In the prototype omega, I feel an enhancement on the impact, the speed and the amount of bass. Perhaps it’s the reason why they create this prototype, to improve on what the original is lacking. The density of imaging of sound also improves by a bit. Be caution that I cannot remove the effect of the different earpad and casing on the overall sound comparing to the original so the effect I mentioned above might be due to them. Despite all these merits, there is something lacking in this prototype: The openness of soundstage and the super-revealing details on the original omega. If omega scores 100 and 009 scores 85 in the aspect, I will give a 95 to this prototype. The transition from mesh electrode to plate electrode seems to be a double-sided sword. I remember in one of the Stax staff interviews they explained on Pros and Cons between mesh and plate electrodes. You give up something to exchange for another. Nothing is perfect unless you pay a double.
    1 point
  12. Probably Saw Stop with an integral router table.
    1 point
  13. They offer a 30 day no questions asked return policy. https://www.festoolownersgroup.com/festool-jigs-tool-enhancements/ts-55-anti-tip/
    1 point
  14. Jim was talking about cutting the miters on all of the trim and base pieces.
    1 point
  15. Maybe the opposite of Angels in America, watching Heaven's Gate: Cults of Cults (HBO). "Cult" is obviously a loaded term applied often fuzzily (and/or from another questionable groups own biases), but have always been interested in this one, as I may have mentioned before, a Heaven's Gate ad is what I saw a few months after moving to California three decades ago, and sent 6-7 copies of it back to my friends in Ohio to say "I've arrived in California!". One of them was to a girl I previously dated in a different international "techno-focused California cult" (sorry, WCG), which seemed normal-ish in comparison (and I stupidly only made the connection after both dissolved). Anyway, cult docs almost never hit the mark when it comes to understanding the attraction of of their followers, instead demonizing its leads, and this suffers the same, but still fascinating. And as always sex is a big part of it. Who says Star Trek never hurt anyone?
    1 point
  16. I have now pulled some numbers from the circuit. And I took more pretty pics, which I‘ll start off with: Now for some numbers: PSU voltages: V_HV_pos=402V, V_HV_neg=-403V V_LV_pos=14.88V, V_LV_neg=14.88V Current sources: Right channel voltage drop over the RN60C 49R9: V_ccs_pos=857mV, I_ccs_pos=17.17mA V_ccs_neg=856mV, I_ccs_pos=17.15mA Left channel voltage drop over the RN60C 49R9: V_ccs_pos=862mV, I_ccs_pos=17.28mA (adjusted to 857mV/17.17mA) V_ccs_neg=856mV, I_ccs_pos=17.15mA On the left side the initial B+=20V current source adjustment was the following: V_ccs_pos=845mV, I_ccs_pos=16.93mA V_ccs_neg=847mV, I_ccs_pos=16.97mA So going from a B+ of 20V to full a 402V led to an increase in current of a meager 1%. Next up is gain, THD and clipping. Input is a single ended 0.1V at 1kHz from the Boonton 1121. The – input of the carbon is grounded through a 220R resistor (equivalent the output impedance of my preamp). The output is measured unloaded. L+: V_out_rms=42.5V, gain=52.56dB, THD=0.3% L-: V_out_rms=46.0V, gain=53.26dB, THD=0.095% R+: V_out_rms=41.9V, gain=52.54dB, THD=0.38% R-: V_out_rms=46.6V, gain=53.37dB, THD=0.09% The THD is higher than I would have expected (the Boonton‘s baseline is at 0.00085% btw). It‘s mostly 2nd harmonic though. Here’s how I took the gain and THD readings: And here’s what the THD spectrum looks like (notched out fundamental at 1kHz, peaks at 2kHz and 3kHz, and maybe even 4kHz): Here we see the output just before clipping: CH2 in purple is the input signal to the amp, 1kHz at like 1.5Vpp (518mVrms): CH1 in yellow is the output signal. 764Vpp. The probe is rated for 600Vpp at its 10x setting, so that was stretching it a bit… And here we see clipping with an input signal of 1.9Vpp (668mVrms): I also took temperature readings after the amp has been running for 2hrs or so. Ambient is at 24°C. Right behind where the SiC Fets are mounted, the heatsink temperature is 45°C (113°F). The corner the farthest away from where the bracket connects to the heatsink is as 41°C, so the heatsink gets utilized reasonably well. Inside the case it read 43°C. I realize that the brackets are not positioned ideally on the heatsink (too far up), which is why I have used chunky brackets, thinking that the thick material would conduct heat nicely. Seems to work well enough. Seeing the 21°C rise in temp makes me think I could try upping the current. Calling it a furnace was overstating it a bit perhaps, but the whole enclosure gives off an impressive amount of heat already. I also employed the opto servo btw, going up to 17.5V positive offset before putting in the jumper. The amp now comes on with like 1V offset, which goes down to a few mV after a couple of minutes. I don’t think I could hear any sonic difference between going raw vs. opto servo. So, two questions remain: Why is THD so high? I would have expected a lot less. Is it the frontend perhaps? And what's up with the gain imbalance? It’s consistent between polarities (single ended input, - input grounded). Could that be the cause?
    1 point
  17. Congrats on your finished build! I did a similar (in terms of size and layout) single chassis build, with the amp mounted in the upper part of the heatsink. Dual 450V and 20mA. At steady state, the temps hover around 46 degrees celsius (ambient 27 deg) on the heatsinks directly behind the amp boards, 43 deg behind the GRHV, and 41 deg at other parts of the heatsink where nothing is mounted behind. Not sure about you but I feel it's quite safe to push it to 20mA if you're getting a similar temperature.
    1 point
  18. No worries, it’s a lot different doing individual tracks in a larger mix than it is doing it on a whole stereo mix. I’ll be asking the former. Also, not really worried about synchronization if it’s a foundation track.
    1 point
  19. With the complex design you chose for your first big project, I'd say you did pretty well. I would cut the trim long, then put it against the actual box to mark the angles in place. But that's just experience. That comes naturally. What doesn't come natural is the eye for design and the ability to turn that design into an actual object. You seem to have that in spades. Most would have built an easy square box. Kudos! As for putty to match the Purple Heart, simply make some Purple Heart sawdust, mix with wood glue into a thick paste and putty all gaps before it dries. Over putty, then sand level after dry.
    1 point
  20. RIP TdP! As a reel to reel fanatic, his mods to gear like the ATR102 are legend and his 825Q mastering equalizer is considered by the mastering engineers I know to be their fav. https://vintageking.com/ear-825-equalizer
    1 point
  21. "MAC n cheese." Sing it. zoomerhumor.jpg These three were shot with a Mamiya medium format camera: Click for much, much larger. David Prowse rehearses with Alec Guinness. "You vs the guy she told you not to worry about." meow_irl #ScottishPeople
    1 point
  22. Thank you to all you lovely people... And Brent too. I shall celebrate by setting fire to some budget audio gear.
    1 point
  23. Thirded for Arm R Seal. That's what I used on the Colossus, as well as many other projects. I like to use foam brushes to apply. Put your brush inside a ziplock bag between coats.
    1 point
  24. Be happy you don't live in Valdez, AK., where the snow often covers houses completely.
    1 point
  25. Thanks for the encouragement, y'all. Getting closer now:
    1 point
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