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  1. We’re launching a new company – Eksonic – along with our new amplifier called Aeras. Launching an audio company is something I’ve had in the back of my head for many years and I’m proud to be able to bring a passion to market. I've been building my own version of the DIY T2 for quite some time now and have long hoped to capture the spirit of the beast in a smaller single chassis design that's more accessible to many. We think we've accomplished that with the Aeras. Aeras is the result of endless hours of circuit design and analysis, brainstorming and many iterations of prototyping and testing. Our initial users have had great things to say about this new amp. We’re going to be launching the company formally at the NYC CanJam later this month. We’ll bring our DIY T2 along with the Aeras so people can hear them side by side. I hope to see some of you at the launch
    61 points
  2. I have been getting back at this..working up to a limited run of these as the STAX SR-X9000 and Audeze CRBN have made that need to happen. But the chassis is extraordinarily expensive and difficult to produce, so I am working at ways to fix that. Also need to put it on the scale, thought it was 45lb but feels more like 60lb haha. It's really not that big of a footprint (13.5x18), but it makes the BHSE look like a toy. Power consumption is 190-200W depending on tubes, with 90-100W of that being heaters. The bottom of the amp is ice cold and the top is pleasantly toasty. The first 3 stages have recessed slide switches on top to switch 6.3 to 12.6v heaters, so common tube types are: 1st: 6SN7/12SN7, 12AU7 and many others w/ 8 to 9 pin adapter 2nd: 6SL7/12SL7, 12AX7 and many others w/ 8 to 9 pin adapter 3rd: 6N6P, ECC99, 12BH7A, possibly others such as 5687 w/ pin-out adapter 4th: Emission Labs 20B-V4
    29 points
  3. It started with repairing a badly damaged shangri la jr driver 2 years ago, I almost rebuilt the set from the diaphragm to the stators,and of course the dust cover😦 The first thing I discovered is that the 'nano-technology' used by hifiman actually comes from the covering used by indoors aircraft model enthusiasts,the name is OS film and it is still available on ebay or https://www.indoorffsupply.com/shop/os-film-25ft-roll-1 the driver of the hifiman estats is completely glued which is similar to the early stax lambdas, but hifiman glue is significantly worse...after opening the driver i found that they only use OS film for their dust cover, the diaphragm is another PET film ~ a little bit thicker but with much better strength. In order to repair the diaphragm, I found a seller on Alibaba who can provide samples of Toray PET film with thickness below 2 microns at an acceptable price,and use the inner tire stretcher to stretch the film like any other diy estats ,Then test it with a 10" subwoofer and minidsp umik-1 to find proper F0. conductive coating is another serious problem,I've tried quite a few methods including antistatic agents like licron crystal, ANTISTATIK100,floor cleaner,carbon-based coatings such as graphene, and alcohol-soluble nylon, even tried nano-silver wire solution and metal evaporation...Some of them are sensitive to humidity, some arcs,some are ridiculously expensive, some have uneven surface resistance distribution, and some are sensitive to temperature changes. Yah~ finding the proper conductive coating is the most difficult part especially for a layman. unexpectedly, I tried to search for hifiman patents, hoping to find something useful... here's a patent showing that they used some kind of metal oxide nano particles as conductive coating for their estats. emmm,very interesting...🙄 By consulting with chemistry professionals, I decided to try a solution called ATO (antimony doped tin oxide), there are many antistatic agents I have used before have ATO ingredients though. I got some ATO alcohol solution at concentration around 10~15%, it works really well, and coating appearance is somewhat identical to hifiman diaphragm! The last thing is to repair stators. hifimans probably use #150~300 brass mesh and solder their edges to a 2mm thick aluminum base plate PCB board, then glue the rest of middle part. I've tried tensioning those brass mesh with embroidery frame and manual screen stretcher,but it is not tight enough to stretche brass mesh in this way, the mesh itself is too strong to tighten it up... then I found some brass sieves with different meshes on taobao and these machined copper screens are perfect for making DIY mesh stators... after everything's ready,i desoldered OG brass mesh, cleaned the copper foil, applied low temperature solder paste, and carefully soldered the new brass mesh with a heat gun. During the process of repairing shangri la jr, I started planning to make some bigger mesh stator estats... of course,the target is its big brother shangri la SR😈I received a set of the first batch of shangri la sr made in 2016,here is the headphone inside,yap~inherited the tradition of hifiman with such horrible workmanship...😱 however,SR sounds not as technical as the X9000 though,but with more pleasant and passion. SR uses 3mm thick aluminum base plate PCB instead of 2mm on JR version,2 black things in the middle are to prevent the diaphragm from attaching stators,The D-S gap is around 0.7~0.8mm(thickness of glue included) which is identical to JR version,active area is close to 6400mm² ,that is pretty large diaphragm size for a commercial product though,but less 5300mm² of area on stator allows air to pass through. I tried to use the 3mm FR4 board as mesh holder at first time,however,mesh stator disassembly is not an easy job...therefore,I changed to use 1.5mm brass plates as the mesh holder and glued the copper mesh to it , brass mesh is also replaced with higher # red copper mesh for more convenient adhension. I spent most of time adjusting the tension of the diaphragm and finally found the tension needed for F0 similar to OG SR ,the clone driver has a slightly enlarged diaphragm(6839mm²) ,0.73mm fr-4 pcb spacer, and everything is screwed to the housing cover. The frequency response of clone and SR are generally similar,but the sensitivity difference between the two is about 1.5dB actually,SR is more diffused...clone one sounds a bit more clearer. SR has obvious recession between 1-2kHz,it may be caused by a sealing problem in the space between the driver and the earcup.... It's unlikely to be solved without EQ, but it doesn't sound as bad as it looks from the graphics. one more thing... Every shangri la must have a throne , so I made one for my mutation🤣
    27 points
  4. Arrived yesterday and it really opens up every electrostatic headphone that I own. I was looking for an amp that can bring more bass out of my HE90 than HEV90 so I drained my pocket to bid on this and now I am very satisfied. The hev90 has a romantic sound but the t2 amplifies every piece of detail, expand the soundstage to what ever possible with extreme fineness and sweetness. Buying any head-fi gear at this price is ridiculous but considering the previous closing bid I think I got a fair deal. And it is so rare to have T2 being sold alone. I do not need another pair of omega so this deal saves me a lot of money. But this amp's functionality in long run is questionable. I hope my handful of obsolete FETs stock will save me some pain when I need to fix this in the future.
    27 points
  5. Finally, I’ve had some time to sit down and dot down my final thoughts on the CRBN. They’ve been here for a couple of months, but I really wanted to have a Carbon CC up and running to try them on before I wrote anything final. I rustled up some pretty ghetto front and back panels this week, so I finally have one for my own system. Feeding it is a Denafrips Terminator DAC but I’ve tried it with a number of other sources plus whatever amps I’ve up and running at any given point, KGSSHV, KGST, CCS modified Stax amps etc. Now I want to start with how it’s been living with them for the past two months, in a word flawless. No issues at all with this second set, no imbalance, noises from the drivers… nothing like that. They are also supremely comfortable, and I’ve worn them for hours on end with no discomfort. Now this is Iceland so not exactly warm and the all-leather earpads might be an issue in warmer climates. Audeze might make hybrid pads like the Sennheiser HE60/90 but here I just open a window to cool down... 😉 Also, a word on driving them. They are inefficient and do need a lot of power. Anybody claiming otherwise is just full of it and thinks gain and position of the volume knob has anything to do with power levels. They are not quite 007 bad in this regard but they do reward a more powerful amp when pushing them. Baseline for excellent performance would be the KGST/KGSSHV line but even with the CCS modified Stax amps they work well at moderate volume levels. Push them though and yeah… you need power behind them. So how do they sound… well TLDR, how I’ve always wished the Sennheiser HE90 should have sounded but never did. These were my first impressions, slightly oversized soundstage and not as precise as others but far from the mess that is the HE90. Plenty of deep, well controlled bass too but not quite up to the 007 level. They can get bright when the source calls for it, slightly excessively so at times, but far from the forward nature of the 009’s. The soundstage is a bit larger than life, but it makes for plenty of presence and separation so while not pinpoint accurate, they are very close to it. Overall, they are just so balanced and pleasant to listen to regardless of what you feed them. Now for the only real issue, the damping is something which has annoyed me more and more. Now as some might know… I’m a bit picky… just a tiny bit… 😛 and while it is not always apparent, some songs or parts of them just sound off to me. This generally true for every headphones I use so I remove all damping when I can. Also, a large part of why I like the 007’s so much due to their innovative air damping. Now on the CRBN the damping is damn good, but I can still tell it is there. This is not like the Sennheiser HE-1 for instance, where that bloody amp with its mosfet based output stage and joke of a front end just spreads its dirty fingerprints on everything. This is far more subtle and only affects some tracks so for instance, it is too closed in when it shouldn’t be, bass has a twang to it that shouldn’t be there… something like that. This is a very minor gripe, and this is me being super picky so take it as you wish. Still, I’d love to try these drivers with less damping… 🙂 So, this aside, there is so much to recommend here. They are certainly not cheap but just holding them you can see where the money has gone. Plug them into a good amp yeah, they will impress. The only issue for me it they have rekindled an old project, take some LCD-2’s and fit them with custom electrostatic drivers. Anybody know of a cheap set I can buy? 😉 Now I’ve not received my SR-X9000000000000 yet so I can’t compare them but on its own the CRBN is a great product. They are not perfect (what is?) but as a first stab at making electrostatics, they are damn impressive. I’m adding this set to my collection, and they are certainly in my top 5 all-time greats. I really must say they are a breath of fresh air as the releases over the last few years have been such a disappointment. It really has been a 10-year slump now so here’s hoping we get something excellent over the next 10 years.
    24 points
  6. I’m going to post this in its own thread as so many people are asking me for X9000 impressions, and it makes sense to have them somewhere where they are easy to find. I was also going to take some pictures to add to this review but I’m just wiped. Might add some later if these ever present storms let up for some good light. I’ve now had the SR-X9000 here for over a week so time for a writeup... as my email inbox is full of people asking for just that. 🙂 First impressions were very promising, the build quality is superb, and those drivers are just a marvel to behold. I do like the new replaceable cables even, though it is a bit of a copy of the King Sound setup, and they really should include a 2.5m cable and a 5m one, the 1.5m makes no sense to me. The earpads might be a tad too big in terms of open area for their own good but they are well made and comfy. That new arc design is also excellent, far better than the 009 mess. The inspiration from the SR-Omega is clear but the build quality here is far, far better. Same loose feeling fit too; they mostly just hang off the head with minimal clamping. I really like how they drew inspiration from them, but I also have some issues with how that was executed… more about that later. The system I’ve been using them in is my main rig, Denafrips Terminator DAC feeding a Carbon CC all being fed from my main PC. Now for the sound, these are clearly voiced in the same direction as the 009/009S but not as horribly colored as those two. They sound open and lively with decent bass and the forward slant is there but far better than the predecessors. I remember thinking… “these are what the 009’s should have been 11 years ago” so yeah, not bad at all. For some recordings they really work but yeah… a few tracks in and the cracks began to show. A bit of a backstory, I’ve likened buying Stax to being in an “abusive relationship” for the last 15 years. Back in 2007 they brought us the 007Mk2’s with all of their issues. Sure, they could be fixed easily enough with some blutac but yeah it was a sign of things to come. At CanJam it was confirmed there was a new version of the 007Mk2’s out and they were even worse (the Mk2.5 as we called them), the blutac helped but could not fix the terrible voicing. Then it was announced a new flagship was incoming and the SR-009 landed in 2011. Now we all remember the clusterfuck that was, drivers failing left and right and forward sound with pitiful bass response… yeah, I’m not a fan. One bright spark was in 2014 when I got a new set of 007Mk2’s and they had clearly been changed for the better. The port finally kind of worked and the voicing was more like the Mk1’s. Then we got the limited edition 009BK (2016?) which I found to be a small improvement over the 009 but still that same sound and finally the 009S is 2018. Less said about them the better, quickest I’ve ever sold one of my flagship phones there… That brings us to the present and since the wait for the SR-X9000 was so long, I had time to bolster my collection to compare against them. I got a used set of 009S just to make sure I didn’t like them (that was still the case), a Voce (not arrived yet due to some shipping snafu’s) and finally the one I really wanted, a SR-Omega with early 007 Mk1 drivers. I had a set a decade or so ago and it’s really the only set of headphones I truly regret selling. I also got my final set of Audeze CRBN’s to compare against the new kid on the block. I had a lot of fun doing so and after a few hours I gravitated to a direct A-B test of the SR-Omega/007 against the X9000. Makes sense as they are a similar idea, put a more modern driver into that same basic housing design. That did reveal the two main issues with the X9000’s, the bright edge to everything which is just borderline annoying and more distracting than anything. Second are the imaging issues… First off, the brightness, with the 009’s they were really intolerable, and I’ve never been able to just sit down and enjoy a listening session with 009’s. It’s not that bad here but it’s always present. Some tracks it just blends in and becomes part of the sound while on others it stands out and takes away from the immersion. What makes it worse is that there is no logic to which tracks have that edge to them, bright ones which I would expect to have it… well it just blends in while darker ones have it. Must be a resonance issue as there is so little damping here. Now with the imaging, I think Stax made a mistake having the outside screen angled like that. On the SR-Omega it is perfectly parallel with the drivers but on the X9K, it is maybe 3mm further out towards the front. This or some part of the driver structure might be the culprit for the odd imaging. Let me clarify, they throw a large soundstage but it’s very much a “three blob affair”. Nothing wrong with that really but it’s the front imaging which sounds off for me. It’s all a bit to distant and boxed in while not being as focused as the 007 soundstage. When you pick up on it, it becomes very apparent and distracting. As comparison, let’s take the SR-Omega and SR-007Mk2. The SR-Omega throws a wide soundstage but it’s all a bit loose and diffused. Now the 007’s (all of them really) have a much tighter, more focused soundstage which also does something unique, there are layers to it. With the SR-X9000 it’s more like the SR-Omega (which makes sense) but more localized to the three blobs and the middle one has that odd boxed in effect while being a bit distant. Now other than these two things, these are well made and high performing sets, but these two things annoy me enough for them to not make my top/best ever list. The SR-007’s are more laid back and “darker” but also more neutral and truer to the original sound. The SR-Omega/007 is a more fun and looser version of that sound but those slight deficiencies just make them a welcome change, doesn’t make them any less neutral. They simply act as a bridge bringing those two sounds together, absolute purity of the 007 with the more warm and loose nature of the SR-Omega. I feel I should also talk a bit about the new kid on the block, the Audeze CRBN. Now I’ve had a few of them here, prototype units to the final production version and it really is the antithesis of the SR-X9000 is terms of fit and sound. The CRBN is snug as it hugs your head with thick and supple earpads. The sound is far more damped so it is darker but still very open and expansive. Now they aren’t perfect, they have that slight issue with the midrange presence due to the heavy damping, but it is minor overall. They are really what the HE90 could have been back in the day, more diffused than the 007’s but with proper bass. Nice way to tie back the 007's were always being compared to the HE90 back in the day. Lastly, how are they to drive. Well… as one would expect with a driver this size, they need a lot of power to behave. That brightness will quickly get out of control, especially at higher volume levels when the headphones don’t have enough power behind them. I’ve only tried them on a couple of amps so far so I’ll need more time with that, but I’d say powerful and neutral amps will suit these just fine. Conclusion/TL; DR These are good but not as good as they could have been. They are too forward sounding though not as bad as the SR-009, 009BK or 009S. I crave neutrality over everything else, the headphones should just present the sound with as little an impact on it as is possible. If they fail to represent a part of the spectrum, that’s fine but if they add something… then I have a problem with it. The brightness and imaging issue does disqualify them due to that, but I will keep them around, nonetheless. With some material they work well and plus I’m in a collecting mood… 😉 I'll probably add to review later on as I spend some more time with them. Finally, I’m going to be a bit cynical and think Stax are doing this sound signature on purpose and not for the obvious reasons. This is exactly the type of sound which grabs you on a quick audition or impresses the useless audio reviewers out there who don’t know any better. Back in 2002 the 007’s got no love at all as they are the definition of “unimpressive at first audition”, let along not many amps around at that time which could drive them. Stax are clearly now trying to make money and not audio purist just trying to make the best product possible, nothing wrong with that, so I’m glad this wasn’t a complete hack job like the 009S.
    23 points
  7. Had a really good service for my Brother, with an amazing slideshow. Several people told some great stories about him. Just really nice.
    22 points
  8. I was on a Boat Past the Golden Gate Bridge To San Francisco Where I had a virtual interview, Aced a test (6/6) and answered some questions, which meant I was approved to take an oath later on. Before: Took an oath, which included obeying laws, something which other particular oath takers and keepers seem not to have been doing . ( Sorry ' Liz) Got a personal Message from Joey B But that's just between him and me. 😉 After: And then with my new cultural sensibilities, I felt the need, The need for speed . And then came home. Q: Fellow citizens, how long do I have to wait for the desire for an F150 with a rack of AR-15's to manifest itself, as it doesn't seem to be happening yet? Should I be concerned? Joanne is scheduled for similar ( minus Tom Cruise) on Friday.
    19 points
  9. And...it's done. We'll, the concrete part. Steve and I need to build a wall, put in doors and a window, get a little electrical done, and then start making sawdust again. This time with a serious dust collection system and air filter in place.
    19 points
  10. Had outer stitches removed from my neck today due a hole made recently extracting a growth. Not sure if it was ever really in doubt, but was tested and a simple epidermal inclusion cyst, thus benign. One of those I never felt in danger, but still felt strangely giddy when the expected test results came back.
    18 points
  11. Some impression of X9000 I would like to share Mine is the first batch in Japan. Serial number is #6. I have it delivered to Australia immediately after launch and receive it today. As my system is incomplete at the moment. There are quite a few good cables coming (Odin 2, Stealth Dream etc). This is only a brief introduction of my first impression of X9000. My setting is: Source: Jeff Rowland Aeris Power conditioner: ISOTEK TITAN + NOVA GII Amp: BHSE (Mullard XF3, Philips Metal Base EL34 Disk Getter), SRM-T8000 (Stock Tube) Reference Headphones: Sennheiser HE90, SR-009S The build quality of SR-009S is worse than SR-009 which made me a bit worried about the X9000. But when I open the box, the SR-X9000 just look gorgeous, its build quality is to the state-of-the-art standard. The grey and brown color combination looks very good. Here are some details of the X9000. Please make sure you read manual when attach the cable to X9000. There are design to stop you attach in a wrong way, but you could still attach the wrong side. I attached the left cable to right unit at the first try and subsequently correct it after I read the manual. There might be some potential harm to the headphone if you attach the headphone cable to the opposite side. RELAXED The main impression of X9000 is RELAXED. Yes, no matter what kind of music you play, it give you a very relaxed sound signature. It is not forwarding sound at all. Even you play most intense Orchestra works like Tchaikovsky Symphony No. 6 by Teodor Currentzis. You will feel the brass and string instruments hoarse like you are getting fxxked by the Orchestra in climax part when you listen to HE90, but you will never feel that with X9000 even you switch to very high volume. Yes, you can switch to a incredible high volume without getting irritable. However, it is strongly recommended you to control the volume as you wouldn't feel any uncomfortable until you feel pain in your ears. It might cause permanent harm to your ear. It depends on your taste if this kind of relaxed feeling is good or not. For me, I have HE90 for Orchestra works so it is not a issue at all. But if you buy X9000 mainly for Orchestra, you might need to adjust your source and accessories to fit its style. To me, when playing Orchestra works, the HE90 is like BPO, or even BSO, the X9000 is like NHK. I am not saying NHK is not good, I just prefer BPO. SENCE OF TABLEAU The second impression of X9000 is sense of tableau. You sometimes feels that 009/009S is pouring music into your ears like water when there are lot of details, but you will never feel that with X9000. Everything is always well arranged in a good manner, in a relaxed way. It is really a pleasure to enjoy music with it. Unlike 009S, the X9000 focus on the whole picture rather than details. Each part of music combines together and you even feel the sound is tangible. To me, it lack of the ethereal and diffused sound signature of HE90. It feels more 'real'. After you listen to X9000, you will find it express music in a more superior and comprehensive way than other STAX headphones. (except SR-Omega, I've never listened to it before) SOUNDSTAGE The X9000 offer incredible soundstage compared with SR-009S and any other STAX earspeakers I have. To me it is even better than HE90 to some extent. It feels like the the sound is emission and diffused in a very neutral way. You will easily forget you are wearing a headphone. (And yes it is very comfortable to wear it) To compare, when you listen to piano live performance recordings, X9000 is like you seating at the audience seat, HE90 is like you seating on the stage and 009S is like you head is in the grand piano. I am not saying SR-009S is bad. Actually, there are some person prefer to listen to Piano in closest distance to feel the metallic touch of the sound. It's upon your taste. SOME OTHER FEATURES Compared with SR-009S and HE90, X9000 is a more neutral sound headphone, it is neither bright nor warmth, but it is still with very significant 'STAX' style. X9000 is not a bass monster like SR-007. But their base has sort of similarity. Compared with SR-009s, the bass of X9000 is not the rock-firm style. It is a more bouncy, soft yet surrounding style bass. It is more like HE90's bass performance. I personally like it very much. But if you really like lot of bass then the headphone probably is not for you. I have tried X9000 with all sorts of music, including Orchestra, piano solo, violin solo, chamber music, Japanese POP, Animation music, Chinese Pop, Acapella, electronic music. It fits almost all sorts of music in my opinion. I prefer to use HE90 to replay Orchestra and Violin works as it is more energetic, but it is after all personal taste. To me, X9000 is too relaxed for some music, it just lack of the spark that ignite my heard. But when I want to listen to music and take a rest, I will definitely prefer X9000. AMPS OPTION I compare my headphones on BHSE and I've also tried SRM-T8000. SRM-T8000 can drive X9000 pretty well just as SR-009S. But overall it is even more softer than BHSE. To me I think BHSE is a better option.
    18 points
  12. I built my sister a redwood clad mailbox stand Then Steve and I tried to dig post holes in dry, compacted dirt before hiring a guy named Sergio to do that task. We set the posts with a high tech expanding foam product made by Sika that worked great. It is in a bag with two bladders that you pop to combine and then pour in the hole. It works very fast and was set in three minutes. No bracing and waiting for concrete to set.. The best part is that Home Depot had marked down these bags from $10 to $2.38 and when I checked out they were rung up as $0.01 each. Two cents for footings is pretty cheap.
    18 points
  13. Retirement is like a permanent vacation. Albeit mostly a staycation. “Up North” for a week of leaf peeping, hiking and discovery. Nicest cabin I have ever stayed in.
    18 points
  14. Built a Megatron. Seems to be the perfect amp to build during the seemingly unending shortage of 10m90s. I used up my final few pieces of 10m90s and C2M1000170D for this simple build, and it gave me some mild anxiety and regret for not hoarding up those sands. However, the build experience and result are worth it. Build process and after thoughts I started off with a pair of generic chassis from Taobao. 32cm wide, 8cm tall, 35cm deep. Silver and black anodised aluminium. They weren't available in other finishes but this looks clean enough to me. They do have some minor scratches and dents if you look hard enough though. The casework was done by a laser etching service provider I found on Taobao. The end result was a clean and modern appearance. Inside the PSU are a pair of +/-450V GRHV, +/- 15V GRLV, delay board and a 270VA toroidal transformer. The idea was to create a PSU that can be used by both the Megatron and the Grounded Grid amp units. These components fit the chassis nicely with little room for a third GRHV board for the 300v rail for Megatron. Outputs are split into AC and DC outputs. Transformer specs: The heatsinks for the amp unit were probably redundant since most of the heat comes off from the top. The amp board could probably fit into a smaller and lighter chassis, but I chose the same chassis as the PSU just so that they can stack. The amp build was straight forward and relatively easy compared to a Carbon build or any of the KG dynamic amp builds, due to the low component count. I did not use any boutique components in this build. The coupling caps are Wima, and the voltage rail decoupling caps are Siemens. Volume pot is an EIZZ-style stepped attenuator, internal signal wirings are pure copper. Special care was taken when routing the heater filament wires to avoid hum. Amp testing and adjustment was simple. Just ensure the all the rails are as spec'ed and that's about it. The voltage offset settles automatically after power on. No need to fiddle with any potentiometer when the amp is powered on, so it is much safer to test than the Carbon or the T2 family. Sound I used the Megatron with ES-1A, and here is my impression of the Megatron after comparing it with GG (on the same PSU), Carbon (450V GRHV 15V GRLV) and Mini T2 (triple GRHV). Currently I am using the Megatron with a quad of Mullard XF2 and PSVane EL34PH. The front end tubes are all Valvos. The sound of the Megatron is warm, slightly thick in the mids, and non fatiguing and airy in the treble. It sounds very natural and the imaging is holographic with good recordings. While it is very detailed, it does not ruin joy if the recordings are of poorer quality. Older or poorly mixed recordings have a smooth timbre and organic vibe when heard from the Megatron. While the Megatron's treble is not as extended as the Carbon's, it complements the overall signature to create a very complete soundstage and convincing sense of separation and space. What makes the Megatron standout from crowd lies in its low end - it is an amp for bassheads. It has by far the most THICC bass compared to my other amps, even more than the Carbon. The bass extends as deep as the Carbon, but the Megatron has a nice lift in the mid bass that makes my ES 1a slam extra hard. Listening to EDMs and fast pop tracks on E-Stats is finally satisfying, and I can finally stash away my planars. Carbon is like an antithesis to the Megatron. Carbon is like a clean cutting razor with little tolerance for inaccuracies where as Megatron adds a lot of joy and flavour into the listening experience. Carbon also sounds a little linear. Although the stage is wide, it is not as deep as the Megatron's. GG sounds more organic than Carbon in general. The GG's signature is quite dependent on the tubes. With the XF2s, GG is warm and clean, but doesn't deviate far from the Carbon sound. The bass isn't as tight and fast, and treble could sound stiff and slightly shrill with the wrong tubes - such as the re-issue Mullard EL34. Mini T2 sounds slightly leaner and cleaner than the Megatron, and has a much smaller bass. It is as enjoyable a listening experience for me, but the Mini T2 was much harder to build - by sheer component count. Tube placement and choices Placing the EL34s in this manner shown below allows one to use two matched quads of EL34 if matched octets are unavailable. Initially I used cheap Linlai tubes for the front end and had issues with sound imbalance and hum - turned out that the tubes were the culprits. Switched to some cheap NOS and the issues were gone. So my advice would be to use well built tubes from reputable makers. The 12AU7s affect the sound significantly. The option to roll tubes makes Megatron extra fun to use. More photos of the internals and the back of the amp coming up soon, when I am more free. I would say that the Megatron is my favourite amp - until I build the T2.
    17 points
  15. @purkcame to visit me today. I showed him all of my DIY headphones. He seemed to like my Omega clone the most.
    17 points
  16. Went to my dad's to visit, just me and him. We talked about our family history (still much unknown), and of him playing basketball in Philadelphia growing up (and how basketball was a "Jewish game" early on). I recorded 2 long videos of it, so good to have this info although a lot of the family history is so vague.... I had mentioned he played against Wilt Chamberlain in a school playground basketball court....he mentioned that Wilt's nickname - before becoming Wilt the Stilt - was "Dippy" Chamberlain! 😄 This is pure gold for me, having this on record now. Karen had also done some recordings of her mom before she passed, about her family and what she knew. To be treasured for sure.....
    17 points
  17. Learned how to engrave with my milling machine today. It's an original Kevin Gilmore et. Al. DIY T2 amplifier with original parts.
    17 points
  18. My very first set of cans were Koss. Granted they were branded as Realistic (i.e. Radio Shack), but they didn't even cover up the Koss logo. RIP Mr. Koss. a younger me (self portrait) with my Koss headphones over my left shoulder on a foam wig head (yeah I was cool)
    17 points
  19. IT FUCKING WORKS. makes music and everything. transformers stone cold after 1 hour.
    17 points
  20. Until trusted person gives a reliable review here, you might study the interior of the new Stax SR-X9000. I let the pictures speak for themselves.
    17 points
  21. Not today, but yesterday: Yumi accepted a job in Durango and we are under contract for this place. Higher interest rates and COVID pricing is a bitch but at least we’re not buying in CA. Time for another HC meet? We got a big basement god people to crash in. https://www.zillow.com/homedetails/96-Walker-Ln-Durango-CO-81303/13939794_zpid/?utm_campaign=iosappmessage&utm_medium=referral&utm_source=txtshare
    16 points
  22. I've had my eye on these for the last year or so but waiting for a cheap set to come up. There are three versions they sell and I found the cheapest one for sale, brand new in the box with the transformer adapter. I'll take some pics of the system tomorrow (shortest day of the year here so... yeah not great for photos) but I've at least a pic of the headphones and the internals of the transformer box. Here they are and I quite like the looks and the build quality. They are using mini XLR's which is not ok but questionable connector choices are a theme here. The stock cable is beyond crap (more on that tomorrow) so I'm using a Stax PC-OCC off my RR-1's. They feel substantial but also light and fit my head snugly at the largest extension. Carbon Fiber headband and the leather is nice. On their site they claim the Minima is supposed to have pleather earpads but these are clearly genuine leather. These look very similar to earpads I've bought from China in the past and nothing wrong with the quality. I shone flashlight through the driver to you all could see the structure, very unusual drivers here. Now onto the adapter box... yeah this is not good. That's it... and yeah there are so many issues here. Let's start with this gem: It's hard to capture on "film" but the IEC input and the fuse holder are completely uninsulated and mere millimeters from the metal frame of the transformers. Thankfully the chassis is earthed but yeah, this is not to code and an instant CE violation there. In the first picture you can also see there is no protection for the transformers at all and we will get to why that is an issue. Now the active parts: The bias supply is driven directly off the mains, no isolation between you and the wall. Now this was commonplace in the 70's but now... I'm not sure this meets any modern standards. The bias supply is a simple voltage doubler and for 117V they just add another doubler on top. There is then a 600V zener clamp to make sure the bias doesn't rise above that threshold. None of this has the elegance of the Stax bias supplies and frankly this is just sad. For instance the LED for power indication is driven directly off the mains, through one tiny resistor. Now you might notice those 3 pin XLR's there and yup, they are the stock outputs for the Euridiche, the Stax output is just for convenience. One of my biggest gripes is with using XLR's as they are in no way rated for these voltages, especially the cheap, no-name, units they are using. Also check out the clerances on that PCB.. bias and high voltage signals less than 1mm apart. Then we have what scares me the most, see those traces which go right to the edge of the board and into pin 3 of the XLR's...? Yeah that is the bias so 600V is sitting there, pressed right up against the chassis with exposed solder connections. Sure this is after the ballast resistors (one 4m7 for the Stax and separate 10M units for each side of the XLR's) but still... They have a lot of faith in the powder coating on the chassis. Finally the Stax socket, 3D printed and fed directly off the XLR sockets. Almost no way to actually cram a Stax plug in there but you know, I almost had to use a hammer. 😉 Then we come to the final issue, on paper these appear to be Stax compatible despite the stupid XLR connectors and similar bias supply but nope... they are so inefficient that my usual test amp (Icepower 50 module with a preamp tacked onto it) was at max volume to get these to my normal listening level. I plugged in my test SR-207's as well and they were at half volume using this transformer box. As seen in the first pic, I've fitted them with a Stax plug but they make the Carbon CC work for its pay so yeah, you need a very powerful amp to drive them. Now finally, how do they sound... pretty damn nice actually. 🙂 This is off the Carbon CC prototype in my rig right now and they are very balanced sounding, slightly dark sounding but very mellow and open. They are not overly forward or bright, unless when called to be and I can listen for a few hours with nothing bad to say really. Bass is plentiful and deep, midrange has a nice presence to it and the soundstage is pretty good. Top end is a tad dark but it is very mild and they make for a relaxing and pleasant package. So TL;DR... great headphones that are let down by being too inefficient, frankly unsafe transformer box and stupid cable/connector choices. Change the cable to Stax and drive them off a powerful amp and the sound is great.
    16 points
  23. Waiting for Jp’s arrival. He has a bunch of he has a bunch of headphones to try out with his Matirx Sabre DAC. I have HP1’’s with the J Grado amp (Gene’s gear) as well as my Lola’s and Matirx Mini Pro 3 Streamer.
    16 points
  24. I had previously talked about the bookstore I'm working on. It's almost open for business and I thought I'd show a few of the projects. The shelves are all solid Cyprus. The boardwalk in the back is Redwood, as is the planter/benches. I didn't build the shed, but had to completely dismantle, move and reassemble it. Honestly, it would have been easier to just build a new one.
    16 points
  25. Ran my first (mostly in person) conference since COVID this weekend. It was nice to see people in person!
    16 points
  26. Cases and heatsinks are a problem for DIY builds. Front panels of thick alloy need machining and tapping as do heatsinks. These items are hard to get machined or the sizes the builder wants are not available. I devised a way of making cases, which eliminated these problems and made for easier case design, lower costs and quicker builds. Cases Made from sheet aluminium alloy of preferably 3mm so only single sheet of material needed. I get the parts laser cut by a company which will also supply the material. The case parts need holes to be countersunk where necessary and are then taken for surface finishing, (bead blasting and anodising in my case). I then take the front panels to be screen printed with the graphics I provide. The assembly is with corner posts and angle brackets cut and drilled, and bolted together. I only drill and tap corner posts to attach base and top panels. The case is basically a box with a front panel on to cover the front of the box. Heatsinks https://uk.farnell.com/amec-thermasol/fch505010t/heat-sink-50mmx50mmx10-25mm-ceramic/dp/2499023 Edit; a link to these was omitted, http://www.amecuk.co.uk/ Element14 has them in many countries. https://www.newark.com/c/cooling-thermal-management/heat-sinks?brand=amec-thermasol I discovered porous ceramic heatsinks and realised that these small, light, self-adhesive items would solve problems. I bought a few and tested to see if they did what was claimed. A single 50mm square of 10mm thick could dissipate 5-10W stuck on sheet aluminium. To make heatsinks you only have to bolt the semiconductors directly to the 3mm plates and place the ceramic heatsinks as needed. They are not expensive, and with a range of sizes you can arrange heatsinks of different shapes. I was concerned that they might unstick but the opposite has been true, they are hard to remove. They are not pretty so I contain them inside the case and organise slots above and below to act as a chimney to allow convection. This works well and they do not run hot. The porous ceramic devices are very effective. I have found that this method is much easier to procure and build. The amplifiers built this way can be smaller and lighter.
    16 points
  27. On the way to Bodega Bay for some fish and chips, and a walk, we stopped in Bodega, to admire the School house from "The Birds" and The Church (St. Teresa of Avila) Ansel Adams took a picture in 1953 So I did (composition from memory), on the last day of 2021
    16 points
  28. After several years layoff I have built a KGSShv Carbon which uses boards I had in and 4 Cree sicfets from several years back (luckily). The power supply is KGSShv v8 and the amps Carbon v6. It has been one of the easiest builds because of a different way of making the cases which I have described in Making diy cases, https://www.head-case.org/forums/topic/18892-making-diy-cases/ It is set for 400v supplies and 17mA output stage currents. It does not get particularly hot in a 20o C room, the heatsinks run a max of 40o at the centre. The power supply pass transistors are bolted to the bottom of the case and the case runs pleasantly warm to the touch. The size is 335 W x 314 D x 155 H inc feet. Weight 8.5Kg. (13in x 12.4in x 6.1in, 18.8lb.)
    16 points
  29. Great hike with the family in the PNW. Man do I love it here.
    16 points
  30. I checked out The Wooden Boats of Lake Leelanau show.
    15 points
  31. Dropped Peter off at CSU on Monday.
    15 points
  32. Another way to build floating shelves, without purchasing the steel supports.
    15 points
  33. Nice caddy! I haven't been home lately and haven't done any woodworking since this cabinet project for my nephew. I can't remember what I have posted about them previously but the ask to make one or two simple cabinets to hang kids clothes morphed into a much bigger thing. Two cabinets that are almost seven feet tall, with two sets of pocket doors to save space in the small room, six foot tall basic shaker doors with inset trim I made from two different pieces of molding, and six shelves in each section and no clothes hanging. Oh, and all painted with latex enamel shot from my HVLP sprayer. Designing and building and painting these monsters kept me up at nights. Steve very astutely took a pass on this one, but thankfully agreed to install them with me. They are super happy with them and filled them with kids crap within two days.
    15 points
  34. We just put the house on the market. Shit is getting real.
    15 points
  35. George Baselitz exhibit was already on the list but we went today to honor the architect as well.
    15 points
  36. I think I just broke a record. Just hung up from a 5 1/2 hr. phone call with my Mom. I just don't have the heart to cut her short after everything she's been through lately. My ear hurts and I'm starving. She really needs an ear to bend though, and as tough as that was, I just want to make her a little happier. I'm sure after she's gone I'll wish I could talk to her for hours.
    15 points
  37. I was getting ready for a bike ride this afternoon and hunting through the dryer for some gloves when I spun the drum by hand and it made a huge bang. Hmmm, that's weird, says I. I find the glove and attempt to restart the dryer and no joy, no spin, no heat, no nothing. So I make the executive decision that this is not going to ruin my ride and inform the family that laundry is off limits for a while. Got in a good ride with two local buds and then got to work. Initial prognosis, the belt is still around the drum so deeper we go... Problem found, the belt had slipped off the idler pulley and then the spring that loads the idler had fallen off so the whole drum had to come out to get at things to perform the relatively straight forward repair. About a half hour later everything was back together and working. Worst part is that the belt is worn so I'll get to do at least half of this again sometime sooner than I'd like but at least it's working again.
    15 points
  38. The new Stax just arrived. Sorry for posting in CRNB thread.
    15 points
  39. This was a few weeks ago, but just got pictures after installation today. It's a floating bench that a customer asked me to build to match their dining table. It's 8/4" Rift Oak.
    15 points
  40. All done and ready to be moved to the deck with the neat razor scooter wheels.
    14 points
  41. Passed the first round of interviewing on my dream job!
    14 points
  42. I was going to name it 'Double the Carbon, double the voltage, double the fun', but I'm afraid that would be too wordy. Ever since I measured the output swing capability of the Carbon, I wanted to see if it can drive my ESL speakers. To do that, I'd need a beefed-up version that can output at least 1kVrms before clipping. That's 1414V peak, out of a ±750V to ±800V PSU. To simply scale up the Carbon amp and the GRHV PSU without major changes to the PCBs, a few hurdles would have to be overcome. First is the 900-V rated 10M90s in the cascode CCS that bottom out with ±450V PSU. When I was browsing the high voltage FETs at Mouser, I found the UnitedSiC UF3N170400B. It's a 1700V 6.8A SiC JFET, naturally in depletion mode, perfect for the upper device in the cascode CCS. The threshold is about 9V, which helps the DN2540 to get further into the constant current region yet keeps the power dissipation still in check (no heat sink needed even with the TO-92 package). The drawback is the package. The TO268-7 isn't too friendly for a DIY thermal solution. I had a few carrier boards made with aluminum-based PCB. According to simulation, the little board would give me 9 degree temperature difference from the package case to bottom of the board when the FET is dissipating 9W. I chose black solder mask, hoping to get a bit better heat radiation capability. 10 boards cost me about $3 at JLC. They also have copper-based PCB with a special process to have the base copper flush with the top surface for a much, much higher K. Too bad the NRE is about $150, so I chose the cheaper route with aluminum. The insulation is good to 3kV so this board can be bolted directly on the main heat sink without additional insulation. Isn't that great? The next bottleneck is the 600-V rated STN9360 when the PSU voltage reaches ±600V. I replaced them with the 900-V rated 2SA1968s. Thanks to the cautionary words from spritzer, I started cleaning up traces with high voltage differential that are getting too close to each other. I removed the middle pad 'A' in the 10M90s footprint, and re-wired a couple of traces on the back. With the bias changed from 24V to 13V above B-, the JFET can be used as the output device as well. At almost $10 a pop, they are considerably more expensive than the SiC MOSFET they are replacing. So the full-JFET configuration shown below is more of a proof-of-concept than anything else. The feedback dividers are changed from 200k:200 ohm to 440K:470 Ohm to maintain the gain and allow the output swing to double, without having the feedback current overtaking the idle current through the input JFET. Two 10pf 1KV caps are in series as a 5pf cap, since I don't have the proper 2kV rated caps. Not a great idea. I was lucky it didn't blow up. Technically the board is now ready for up to ±850V. I tested the SiC-JFET 'doubled carbon' config with ±400V PSU. The performance is slightly worse than the original Carbon. Is it worth the effort? We'll see. (To be continued...)
    14 points
  43. Finished, with minutes to spare a set of these. Kasia asked, of course, why there are two openers on each and the answer, of course, was because this is fucking Head Case. and not that I gave fuck all thought to where screws were coming through the front when laying out the keyholes in the back
    14 points
  44. The saga of messing with my 2nd Carbon build continues. Since the circuit is very close to the Grounded Grid, I'd like to give it a try. Being hesitant to spend big bucks on a nice quad EL34, I have been on the lookouts for a cheaper substitute. The curve of a pentode looks a lot like that of a SiC FET. I need a pentode with the following properties: The plate curve should have low kinks or no kinks at the low Va range. The lower the 'knee' the better. Low Ig2. Ig2 should be much smaller than Ia (20mA), ideally 1mA or less under the operational Va range such that Ig2 doesn't interfere with cathode drive/ cathode degeneration. The amount of negative bias needed to get 20mA at 400V should be reasonably easy to handle. High rated Va(max) and Pa(max) for using a higher supply voltage and/or idle current in the future. That means I may need to look into transmitting tubes. And the candidate is... (drum roll please) the FU-50/GU-50! The linearity looks pretty good at around Ia=20mA, from Va=100V all the way to 1kV! The bias voltage is between -20V and -25V, right around what Carbon has. The Ig2 is really low and changes very little from Va=100V to 1kV. More importantly, the FU-50/GU-50 are relatively inexpensive and plentiful. A lot of them were made in the USSR and China during the cold war era. I read somewhere that those were designed for the comm gear used in the tanks and had very little success in commercial applications. I paid less than $3 a pop from Ukraine about 15 year ago. The going price for a NOS tube should be close to a SiC FET today. Well, any tube not designed for audio can be cheap these days. However, that wouldn't stop people from chasing after the Telefunken LS50 and the east-Germany SRS-552s, I guess 😉 Adapting those to the Carbon is surprisingly easy. I removed the SiC FETs and the 20k bias resistor, replaced the two 175k resistors with a 100V and a 130V 3W zener diode for G2 supply. The Ig2 is really small and the two tubes can share one set of the zener diodes. They drop 230V from GND and set Vg2 right at 150V, with about 22V left for the PZTA42 and the offset pot. The heaters are powered by a 12.6V filament trans with one side tied to B-. I could have tied the CT but there was very little hum to worry about. Guess what, the GU-50s work right out of the box. I didn't even need to adjust the balance and offset! The measured performance is pretty decent: Although the distortion is low, the FFT does show some higher order 'pentode nastiness'. I guess the reasons being The pentode is not super linear to begin with. The transconductance of the GU50 is about 1/10th of the SiC FET. The PZT42 has to work much harder and the global NFB is less effective. Something else worth looking into I'm not yet able to seriously listen to the sound, because I couldn't find another pair of tube sockets in my stash for the second channel 😂. If you want to know how it sounds, try it! The GU50 with 400V PSU comfortably beats the KGST (below) on the frequency response and the output swing: Next to try is to use the pentodes on the KGST, or should I call it KGSP then?
    14 points
  45. Working on party favors for a little headphone/craft beer nerd get together this weekend. Took forever to cut the 3D rendering of the logo but all done and used the new keyhole bit to cut keyholes for mounting on the back. Putting sealer on tonight so I can finish with boat varnish tomorrow. Then just add the bottle openers and done.
    14 points
  46. Attained the ability to leave the country (and re-enter legally) Now awaiting communication from 'M' with details of "Your next mission, Mr. Bond"
    14 points
  47. I did sous vide picanha for the first time today. A simple rub of spices, smoked salt and olive oil, then cooked in the bath at 133F for 6 hours. The 'grill' part comes from very briefly finishing on the pellet grill, just one minutes a side, with the flame box open and the temp at the absolute highest I could get it, about 700F! Served with fresh chimichurri, I was in meat heaven.
    14 points
  48. So, finally time to replace the cable of my 007. Birgir and others have probably demonstrated this before, but I thought I'd show some pics for those who, like me, haven't done it before (and, sooner or later it will be necessary). Off with pads and front plate, and the nylon piece covering solder terminals. Solderer's best friend: electrical tape. Some sacrifices necessary too - had to buy and eat a bar of chocolate for the cardboard to protect driver from hot solder. New cable in place. Also adjusted the headband elastic and put on the pads correctly, wasn't done before. Now the 007 sits tight on my head, sounds better and is more comfortable. Promised myself to fix the 007 when I finished my Carbon, so here goes. Build without major problems. MLA brought his variac for startup, and there were high voltages on the outputs. My mistake, had missed to solder one leg of a PZTA56, hanging in air. Fixed that and it works fine. Wanted to keep it simple and clean. Might add a LED when I can afford it.
    14 points
  49. Business side of the cutting board. Figure it will have a long life serving charcuterie to Marin’s finest.
    14 points
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