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Ledisi - Sings Nina

Finally completed my Dynahi, an on/off project (like some of them) for five years. Bought the set of boards from Samsie in December 2015, so I thought I'd just let him know that they eventually came of use! Turned out to be a relatively uncomplicated build, except for a couple of resistors around the THAT340 with too many zeros, discovered by MLA. Also a problem with the -30V side on one of the PSUs. Turned out to be a malfunctioning rectifier. A BC556 popped, but the supply worked once replaced. For a week or so, then the 556 popped again. After the third time I scratched my head, but some sparks from one of the surrounding caps told me it had taken some beating from the faulty rectifier. Replaced that and the DN2540 and now it has played without incidents for a couple of weeks. Sounds very nice and has become my go-to-amp, with some competition from a KSA5 I took over from MLA recently. Spoiled for choice.

Lily Allen – Alright, Still Dead Can Dance – The Serpent's Egg

The Underground Railroad - Colson Whitehead What if the Underground Railroad was actually a subterranean railroad? That is the hook that draws you in here, but it is the journey through antebellum America that really drives the narrative. This has strong vibes of The Odyssey, filtered through Cormac McCarthy. In my opinion this is/was a deserving winner of both the National Book Award and the Pulitzer for fiction. Whitehead really showed me something here. I think I'll read more of his stuff in the future. I read this ahead of diving in to the Amazon Prime series based on it. The book is brutal. I'm not sure I have the stomach to watch the series after reading the book. One of the things Whitehead does masterfully is to have asides where he will go back and show things from earlier in the book in a new light or from a different point of view. While Whitehead by no means is the first to do this, he does it so tactfully and so beautifully that it really elevates his narrative. I'll be curious how they handle that in the show, given how different the natural rhythms of reading a book are from watching a tv series.

LOL.... yeah just busy, been into astrophotography last few years, so I hang out in that world mostly..... https://www.astrobin.com/users/Readerp/

Lower Pool Curry 2.0

Hiromi Uehara, Spectrum solo jazz piano, I forgot how great this one in particular is. E.G., This is just so insanely great! I should also mention that it appears her entire back catalog (including personal favourites, Time Control, Brain, &c.) has been uploaded to streaming platforms Tidal and Spotify, so...yay!

Autumn (Piano Solos) George Winston 1980 Example:

Thanks. If you want to venture over to a third medium, Dawoud Bey: Night Coming Tenderly, Black, is another modern look at the Underground Railroad.

I'm also a firekeeper in ayahuasca ceremonies. LOL Yea, I've gone down that route. I'm on a spiritual quest, huge part of my life now.

Thanks! It's sunny and cool outside today... perfect patio weather.

^ Haven't seen you in a while!

Thanks Dave Ginochio!

One time I had La Grange cranked up, with the windows down, while driving through La Grange. That was fun.

Heads up on the Panasonic caps James mentioned! Recently I found out the Kemet 220uF 50V 105°C has spec'ed little bit longer life than the Panasonic FR and is mostly half the price. You can measure the reference voltage the LT1021DCN8-10#PBF provides between GND and pin 6 (Vout). Take a look at the specs here.

reference voltage is the LT chip 10V normally or 7V version for <=12V output. As mentioned in my original post the opamp compares the reference voltage to a portion of the output voltage and corrects any difference. So for a 20V grlv you will use the standard 10V reference which is in the bill of materials. The grlv is so low noise it could be used in many situations e.g. as a voltage standard for calibrating other equipment. In that case a precise output is needed, hence the trimmers. The wider the range of adjustment the lower the temperature stability which if you are using it as a voltage standard is a potential issue. For a power supply in an amp having exactly 20.000V output rather than 20.1V is not an issue. This is why I don't populate the trimmer adjustment. Kevin even build a grlv using extremely expensive very low ppm resistors and measured the voltage drift over an entire day just to see how the the grlv was and the result was extremely stable but the resistors alone probably cost more than your amp build.... In my experience power supply caps do not make a massive difference to the sound. I go for low effective series resistance and high reliability. Dont forget most of kevins designs have 0.1uF power supply byass caps on the amplifier boards themselves. This cuts out some noise picked up in the wires between the psu and amp boards. So in effect the 4.7uF caps are bypassed anyway (I am not familar with your amp build but its worth checking the amp pcb to see if it has bypass on it - some of the published amp schematics don't show the bypass caps but they are on the pcb.). Where they matter more is when they are in the audio path e.g. as a dc blocking capacitor between two amplification stages. Most of kevins designs use dc servos to cancel the dc and avoid the use of coupling caps in the audio path. The only exception to this I have built is the Megatron and currently that just used wima caps. for the cost of parts connect "audiophile" caps you could be well on the way to buy a cheap ebay variac.... I find the panasonic FR series caps for the 220uF output cap sound good and are quite cheap. I use a wima for the 4.7uF. Kevin measured the GRLV in a clean room when he was working at a university and the noise levels are incredibly low. bypassing the film cap with a medium value pF ceramic or similar might reduce the output impedance at very high frequencies but some ceramics e.g. multi layer can be microphonic... variac is useful especially if you plan to build high voltage power supplies and can also be used to slowly power up the entire amp when completed in case their are issues with the amplifier boards. But if you are on a tight budget a variac is not necessary. You could do the grlv tests powering it up with a current limited dc power supply if you have access to one. DC load is useful simply for its versatility. In reality if it powers up under no load with no issues its probably fine. I use my variac a lot. The reason I like a variac is 1. I can bring up the board slowly and check for overheating components. before there is so much energy in the circuit things go pop. 2. I know if the outer leds don't light at a certain input voltage I have a problem and can stop the testing immediately. If I see the output increasing past the point where it should regulate I know I have a problem. Im paranoid and its all about finding issues at as low voltage and therefore low stored energy as possible to minimise damage. This technique has saved me money. 3. I might not have a transformer with the correct outputs for the power supply I am building and I can use the variac to reduce the output of a transformer to the level I need. e.g. lets say I need 23VAC for my 20V output grlv and I only have a 50VAC transformer. 50VAC might be too high for my chosen input cap and if its not I will get considerable heat in the transistors as they try to drop the large excess input voltage. Instead I turn the variac up until I get the output voltage I want from my transformer... That way I only need to keep one low voltage transformer around to test any grlv and one high voltage transformer to test any GR HV.... 4. if you are planning to build high voltage power supplies the build cost and potential for nasty damaging failures are higher and a variac can reduce the collateral damage if something goes bang. If you are only planning to build one thing and are on a tight budget and build carefully a variac is a luxury rather than a necessity. There are designs for DIY DC loads on the internet I built it myself and wrote custom code for it. My philosophy is test everything especially power supplies well. Also sometimes forum members ask about particular loads or when loads are "safe" or heat output or voltage drop at certain loads. I also can also use it to test the true capacity of batteries, usb power banks etc. In other words its a useful experimental tool for me. If you are on a budget some high wattage resistors would be fine. If you decide to load test at all. voltage drop = current * resistance so if you are outputting say 20V and want to test at say 0.1A (100mA) then V/I = R 20V / 0.1A = 200ohm. power = V * I so 20V *0.1A = 2W so a 5W 200ohm resistor should be ok for this current draw. power requirement will go up with current draw so for 0.5A at 20V you will need a 40ohm resistor and the power dissipation will be 10W so at a minimum you will need a 15W resistor. Many high wattage resistors specifications assume they are bolted at a suitable heatsink so by the time you have purchased a range of resistors and some heatsinks you can get into the price range of a diy dc load which could handle 100V multiple amps be programmable, run automated tests etc.. If you then build a power supply with a high output voltage say 30V all these resistors will have too low wattage ratings and the current draws will also be higher. A Dc load provides a current draw which is independent of the output voltage of the device its testing. load resistors cant do that. But again if you are only planning to do one build and or are on a budget load testing is optional. Im using a cheap one of ebay. It works for me. the grlv is an easy build (unlike the gr78/79xx smd boards), so as long as your soldering technique and attention to detail are good there is a very good chance your grlv will work first time. I wanted my build guide to be comprehensive, it was not my intention to scare you into buying test equipment you might not use much. Good luck with your build. James

I've always wanted to say this, but being gay I never get the right opportunity... Hey, nice rack!

Inspired by today's Tiny Desk: A Common Turn Anna B Savage 2021 Example: Studio version of the first song from above:

Playing Courtney Marie Andrews' Old Flowers, a breakup album reflecting on what once was, which was on constant play as we settled in for the pandemic, and Maple Glider's To Enjoy Is the Only Thing, heard pretty much non-stop over the last week (and mentioned here several times), a celebratory look towards connections and the future. Love songs can be goofy, but I wonder if these will end up being my COVID bookends (well, if we're approaching an end, probably too optimistic as rates are increasing nearly everywhere).

And to make room for more incense!

Set back up the equipment rack Steve gave me a long time ago, to get some of the mess off my desk.

Thems fightin words round here.

Uhhh, I have to downsize. I don't need 20 headphones. That said, I have six or seven HP1Ks and intend to only keep one of them. I'm also going to sell the BHSE, but keeping the balancing Act. Going to sell all my stat gear, actually. Way too much stuff. I rather it gets put to use by someone who will enjoy them. I'll be posting stuff at the other place but if any of you all want dibs, just say the word. Thanks for all the good wishes! Forgot to mention that, of all things, what I surely believed beyond a shadow of a doubt would receive a big "HELL NO" from her were the massive obelisks that are the Cain & Cain Abby & Bailey speakers... with matching subwoofer. Turns out she absolutely loves the way they look and says they go well with what she had in mind for the living room. So they get to stay.

After DakhaBrakha's rebroadcast SFJAZZ concert last night, hunting for more. Self-described ethnochaos. Before members getting married... After getting married...

Here are the feet - there isn’t enough travel in them I think. I probably need another solution than the motor mount (male stud, rubber, male stud - which goes into the aluminum line footer and the shiny round circle thing on the top) idea which is stock for these VPI tables. There is a slight gap on purpose to suspect the table so it’s just decoupled via the rubber… the wood is just attached via glue dots to the underside of the plinth to hide the motor mounts.

Frank Herbert's The White Plague. He did other stuff besides Dune. I have no idea why Hellstrom's Hive wasn't a movie Perfect scifi horror..

Today in "no good deed goes unpunished" I divested myself of a bunch of things including a pair of JBL 630s from the mid 1980s. In the process, my wallet disappeared. I noticed it was missing when at the checkout of the local grocery store. Two calls later and neither place I'd visited had seen it. I've torn apart my house and my car, but it's just flat out missing. Great way to start the weekend.

Got gas. Thanks hit and run brodozer.