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I’ve been driving Esmé crazy with her new name.

In a previous post I mentioned the less-than-ideal performance when Carbon is powered by a ±400V supply, and I suspected that the lower Vce on the PZTA42 is the culprit. Now it's been proven. The PZTA42 being a high voltage transistor, has a non-linear region at low Vce, as the slanted curves you can see on the upper left side. With 407V on the negative rail, the transistors on my board works at Vce=8.4V and Ic=20mA, right around the knee. The global negative feedback would have a hard time correcting that non-linearity. It also explains why some people prefer setting the Carbon at a lower current when powered with ±400V supply, as it also improves the linearity of the PZTA42, albeit to a lesser degree. I guess Kevin chose the high voltage PZTA42 to deal with the power-on transients. I have a quick and dirty fix. Just bias the SiC MOSFET a little higher to give the PZTA42 more headroom. The SiC MOSFETs are biased by two 175k and an 20k at the gate. Reducing either 175k or increasing the 20k would do. The goal is to move the PZTA42 operating point to the right, well into the constant-current region (parallel lines). I would use Vce=14 to 15V. Pushing it even higher would increase the power dissipation on the PZTA42, eat into the max output voltage swing and have diminishing return. What I did was to put a 260k resistor in parallel with one of the 175k resistors. YMMV because it has to do with the operating point of the PZTA42 in your circuit, the Vgs(th) of your SiC MOSFET, etc. After the quick fix, one of the channels now measures as good as with the ±450V supply. We can see that the max output voltage is slightly less compared to with ±450V supply. The difference is subtle with the log scale, though. Now I'm continue to work on the other channel and see if I can find something else.

Finally decided to just go buy the Shop Fox sander at the local place and was surprised to find it over $100 less than the Amazon price. #Winning

Getting better by the day. Niche grind setting dialed in at least for the Marmot beans and the pull protocol is getting refined and better by the day. If nothing else the pucks are coming out picture perfect so there's that. Between the guidance from this thread and Hoffman the Flair learning curve has been quite steep. The only drawback is that I get so excited with my progress that I keep making new cups of espresso back to back and get such a caffeine buzz I would swear someone spiked my morning oat milk with amphetamines. Another drawback is that my 250 Mbps fiber optic speeds are too slow and I am now searching for a provider who can provide Teraflop downloads. I can now attest that I am three times more productive than I was before my Flair 58 purchase.

Project Hail Mary - Andy Weir From the author of The Martian, this is another "science the shit out of it" book. It is extremely entertaining. If you liked either the book or movie of Martian, this one is a no-brainer. Wikipedia says the movie rights have already been snapped up. I'll be very curious how they make the movie work for reasons I won't spoil here.

*note for the future, send Nate the earthier coffees* Experimentation with beans is how I ended up roasting...

Samus

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. 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.

I have no idea where else to post this, Home of Republican who crafted Florida’s ‘Don’t Say Gay’ bill is destroyed by tornado. 🌪️

^ I really enjoyed PHM. The audiobook narration is excellent.

While there are sources too numerous to cite for beans the fact is that some experimentation is required, at least for me anyway. One, some beans and their flavor profile simply do not work for espresso for me. Two, some suppliers are so inconsistent in what is available that there’s no way to have consistently good coffee (I have definitely found beans that I don’t like for either espresso or coffee). So for me it was about finding a reliable source with enough choices and supply that I know what I’m getting. Like every other vice in life (it seems) coffee has gotten radically more expensive in the last 10+ years and for me, my sweet spot is in the $15-$20/lb range with medium or darker roasts that are not depicted as “sweet” or “fruity”, generally speaking.

My mother's maiden name is Styants, which is pretty unusual (like Samost). Because it is so strange it is easy to trace back. I've got as far as the late 1600's, but its root is the Anglo-Saxon Stigand. In fact the Archbishop of Canterbury in 1066 when William of Normandy invaded was called Stigand. But clergy back then would commonly take a wife or two, and/or other women, so who knows - I might date back to a very naughty Archbishop 960 years ago.

Just ordered a Happy Tamper. I don’t know why, I have plenty of tampers, but it’s something to do I guess.

I am trying my best to avoid the rabbit hole of sampling different beans from every source that is out there. The choices are endless and way too varied.

That's awesome, Augsburger. I also found the learning curve on espresso to be a bit steeper than I expected and despite all the video watching and reading I did, it still amazes me how much changes over time (i.e. w/o changing beans) and from coffee to coffee. Very dynamic and alive if you will. Cool when it is not torturing you...and very nifty when you really nail a pour. Happy caffeinating... HS

^^^ Nothing will beat Voltron-level! 😄 BTW, one additional funny point about my name: when I was looking to get the samost.com domain rights, I got notice it was already in use. My first thought was a cousin of mine in NJ, he was very "internet aware" at the time, and I thought he may have reserved it. But no....samost.com was used for a hotel chain in China!! They've since given it up, and I claimed it; but that was a crazy find. And now, samost.com.cn is for the "Samost Optoelectronics Technology Co Ltd" Has me curious if there is any connection....

Me 3.....my last name, Samost, is quite unique. I have been called Samos (and there is a cabinet-maker family near me with that name), or Samoset like the Native American Tribe. When we first moved in our neighborhood, someone told me they were excited because they (didn't fully catch my name and) thought I may be related to John Stamos 😊 On the other hand, I love having this unique of a name. Pretty sure that anyone with that last name in the USA is a blood or marriage relative.

The Flair 58 is *brutally* honest. I can’t imagine a more transparent espresso device, except for my Pro2* I mean, it is “what you put in is what you get out” at every single stage. Of course that is a double-edged sword; when it comes together, though, it’s magic. I really love mine, and I’m glad you are getting it dialed in! *The Pro2 not having a heating element and all. Actually the standard brewheads are even more brutal than that because they don’t have the same thermal mass as the Pro2 brewhead. But you get out what you put in: no more, no less.

I did! Several, in fact. Moldova's a small country, so I got to see quite a bit of S.

From the link above it looks like Maersk isn't the only shipping outfit to pull out. It might be the biggest though by a decent margin. Nestle's position is totally untenable. That it is "only" supplying "essential" items like baby formula and pet food to Russia misses massively the point that a number of Ukrainian cities are under siege, the population is starving, and have had no power, food or potable water for weeks. And they are having seven kinds of shit bombed out of them daily. Well Mr Ulf Mark Schneider with your $20m salary - how about some essential items for Ukraine? And how about pulling the plug on Russia, like over 400 companies so far? Bastard.

I only changed the LT1021 with the cheaper LT1236-10. The latter has the same performance as the LT1021 except the long-term stability which we don't need. Oh, and I used the DN2540 in TO-92 package for lower cost. Nothing is different from the original circuit electrically. If the output of the GRHV is low, chances are the passing element (SiC MOSFET) is not damaged. A series linear regulator such as the GRHV is probably the easiest circuit to troubleshoot. Jut need some electronics basics and a lot of patience...

Just saw this, Greg; your grind is definitely too fine, as everybody else said. My basic recipe is a 1:2.5 at 4-6 bar in about 35-40 seconds, not including pre infusion. My recipe varies, but I almost always pull the lever gently, with no pressure indicated, until I see the first signs of coffee in my shot mirror (pre infusion), and then I pull with pressure. I’m somewhere around a 15 on the Niche (mine is calibrated just a smidge past the calibration marking). I’ve done the “too many variables at once” plenty. It’s easy to do. If you find that you are getting sour shots with the coarser grind I would updose a little. I try to not make tamp pressure part of the dial in (It’s why I switched to a calibrated tamper), but if it’s sour at the new grind setting you could try tamping just a little harder.

@Augsburger - excellent choice to recalibrate using an alternative beverage.

hmmm. But I like Bonnie Raitt, Tori Amos, Reba McEntire, Florence Welch. Oh wait - they are all female..... hmmmm Ah ... Trey Anastasio, I like him... Ha, I win! Wait ... what did I win?

So, I was watching an Ed Sheeran cover by Scary Pockets, and I thought to myself, what am I missing with Ed? I just don't get it for some reason. I have heard his music all around and many covers. So, I sat down and listened to and hour plus of his songs. They were recorded well, the melodies were nice, the lyrics were mostly sentimental but well crafted. But still nothing caught me, nothing to say, 'Ah, now I get it'. And in the end maybe that is it, it is nice, but not for me. 🤷‍♂️ etc...

Do we have the technology to remotely poison Putin's dick? That way the next time he has it up Trumps ass, we can kill two birds with one stone.

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

It is clearly playing

https://www.nestle.com/brands/coffee/blue-bottle-coffee If anyone here is interested in stopping their patronage of Nestle (see the comments in the WW3 thread), this is important info -- Blue Bottle was acquired by Nestle a few years ago and is still owned by them.

Something nasty for you real freaks out there. You know who you are!