Leaderboard

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.

San Anselmo style Pizza For ...

Celebrating the Birthday of Corrinne Bedecarre.

One of my favorite esoteric music jokes from the great Sanjeev Kohli: "Little known facts about them -- they were not actually twins, but they did have cocks for toes." Fine follow on Twitter @govindajeggy. Nobody does worse puns.

I turned 20,000 days old today... (yes, really) ...and counting

Had the best dinner. I had Steak Frite, but we kind of shared everything. Finished the evening with cones from Fairfax Scoop. Sorry no pics. The ladies didn't want me showing pics of their tripple scoop towers. Let's just pretend she does it for proper speaker separation.

https://www.seriouseats.com/detroit-style-pizza-recipe Followed this closely, including the sauce, and buying the pan from Amazon but I was able to get the Wisconsin Brick Cheese locally here. When I made it in California, I used mozzarella for most of the pizza, but used jack cheese around the perimeter because you want a little more oily cheese to melt and crust up the edges. Really tasty. Alden likes pesto so that's why one third is green. 😁

Qobuz finally has this one.

You don't look a day over 19,000!

Superunknown (20th Anniversary) - I chose not to go with the Super Delux 4h:15m version. Soundgarden 1994 https://album.link/i/1440811129 Example (hard not to just post spoonman): A lot to like about this album...

Speaking of SFJAZZ, new this morning: 😁

So you'll drink to that? As will we all. Cheers to 20KiloDay Mikey, Or 10TonDay Mikey in freedom units.

Test Tone @ Home live right now: https://mixlr.com/illuminator/

Thanks for making me look -- Tidal now has it, too: https://tidal.com/browse/album/239031935 Haven't heard this in forever (I did buy it on CD way back when, so it's probably in my collection somewhere, still with the shrinkwrap on).

Not sure if this is already widely known, but Cookie Marenco heard Laurie Anderson mention it, then did post to tell others. Radio Garden is a very cool app where you scroll the Earth to find radio stations. So currently listening to: http://radio.garden/listen/yumi-fm-93-0/aMOv7kiE Here’s a good starting point: http://radio.garden/playlist/rare-tongues/9M0t3goK

The black front panel looks amazing! Congrats!

This is what the thread is about. Detroit Style Pizza! With a BIG pepperoni. 🤩

Homework! The interview I had earlier this week gave me homework, so that's a good sign.

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

Please accept my apologies for any lowering of the signal to noise ratio in advance but my sincere and profound thanks (as a philistine of all things electronic) to people like Birgir, Kevin, Justin and the rest of you that have influenced (directly and indirectly) the creation of masterpieces such as the one below and the influence they have on the lives of us mere mortal lovers of music. This is the culmination of a dream of over 15 years in the making: Special thanks to Birgir for his efforts and support to this community at large

Sun's Signature / Sun's Signature. Yo, Cocteau Twins fans. ex.

Shot with a potato, still a good tune.

Carbon is getting a sister. Had a few holy crap this is good moments.

posted for the owner who will comment much further. (for some reason he cannot publish high res pictures)

good soldering technique and understanding what is going on when you solder: (a little wordy, somewhat dated and slow paced but the latter part of the video has lots of useful info). I heartily agree a good quality temperature adjustable soldering iron is essential and it will make soldering easier, more consistent and you will get better joints. Something along the lines of the hakko fx888d (although the use interface is horrible) that has descent power and is reliable and has repeatable temperatures. also good quality solder and good quality flux I would add a good quality multimeter, one that will not blow up in you hand if say by accident try to measure a 400V psu rail when the meter is in resistance mode... and yes I am speaking from experience here.... I was tired had already lecturer for 9 hours that day. its not cheap but I really like the brymen BM869s. - or one of the lower end models they seem to be very well made and robust. If the multimeter supports temperature probe(s) all the better for verify transistor case temperatures are not excessive etc. joe smith one you tube has done some excellent videos comparing and torturing multimeters for reliability and high voltage tolerance. for proper verification of stability, checking for clipping, etc a signal generator and scope are necessary. For a signal generator the bare minimum would be the analog output of a sound card on a pc and some software to generate sine waves, triangle and square. given the high voltage outputs and rails the scope needs to have switchable x1 and x10 probes (x10 is actually divide by 10 so you can get 400V down to a more manageable 40V). Scopes can be dangerous to use since the ground wire on the probes is actually earth referenced and is clipped to something in the circuit which is not at earth potential you get the possibility of a short to ground.... Some form of desordering to 1. fix mistakes, 2 make repairs. The cheap option is solderwick or a spring loaded desoldering pump. The far more expensive option is a desloldering station. For me using a soldering iron and solder wick has resulted in to many lifted tracks and is too slow and clumsy. something like this works well and is worth its weight in 2sj79s. There are many similar types out there. it is temperature controlled and has a vacuum pump to suck out the solder. For safety a variac is also very useful it allows you to slowly increase the voltage going into the psu so that if there is an issue it would hopefully manifest at lower voltages and hence reduce the collateral damage once you get more serious a transistor tester and identifier can be very useful especially to check for bad components or to post mortem when the "magic smoke comes out". It can also do small signal transistor and led matching. if you are going to do any surface mount soldering there are multiple ways to do it. fine tip soldering iron, hot air station, reflow oven. Magnification is useful - . The cheap ones can be really uncomfortable and can slide off your head easily but if your eyesight is not 20/20 I find them essential for surface mount and for generally inspecting joints etc. now some "luxury" items to make life easier etc The duoyi allows you to test high voltage zeners and also aids in detecting fake old stock transistors by providing non destructive transistor breakdown voltage testing. The instruction manual is crap and the sockets are junk. But with some modifications it works well. another luxury is an LCR meter - this can allow you to match capacitors and inductors and also can measure lower capacitances e.g. a few PF than a multimeter can manage. It can also measure the effective series resistance of caps and other parameters so you can compare caps and identify worn out caps in old equipment. super luxury items because you are addicted to building: distortion analyser super luxury? ultrasonic cleaner. flux residue can result in joints degrading over time and at the voltages some stax amps work at e.g. the T2 the residue can conduct and cause failures. super luxury: sometimes the provided gerbers are the wrong shape, don't fit your style and you wish you could change them. Sprint allows you to import gerbers, modify and re-export. Its relatively cheap. https://www.electronic-software-shop.com/lng/en/electronic-software/sprint-layout-60.html?language=en super luxury: sometimes you want to make your own schematics: https://www.electronic-software-shop.com/lng/en/electronic-software/splan-70.html super luxury: hands free thin probes for smd or when you don't have 3+ hands available. (The same company also sells hands free multimeter probes). disclaimer, all items shown here I own personally and use regularly. However, other builders may have their own favourites and peoples priorities and build styles vary. So these are suggestions and nothing more.

The pcb files are in zips with the contents in a format called gerber which can be uploaded to a pcb manufacturer like jlcpcb. The gebers contain all the necessary information for the creating the copper tracks, drilling of holes, silkscreen printing etc. Often there are minimum order sizes of around 5 of each type of board so often people have spares... There are no step by step instructions. There is an assumption that you can read a schematic, are prepared to read through some very lengthy forum threads and do basic drilling for mounting boards to heatsinks etc. the information is a bit spread-out. In general you need: BOM - bill of materials to get the right value and size components. Downloads from the appropriate forum thread for your build (and possibly two threads - the second thread being for the power supply) schematics - for troubleshooting etc in the forum threads and or download from https://drive.google.com/drive/folders/0B7egryukiT7_TFlEQlBRejdVdDQ the gerber files for getting the pcbs made in the forum threads or download from https://drive.google.com/drive/folders/0B_iJFfZStuVhSE5nOHBVdTByR1k the specifications for the transformers. in the forum threads. advice. in the forum threads and ask in the threads. in general the markings on the pcbs takes precedence over the schematic or bill of materials (unless the pcb has a silkscreen error). Some amps have more information than others - the threads grow organically over time depending upon popularity, etc. In general support is available for everything on a voluntary basis. You post questions on the appropriate thread hope for someone to answer. There are some very knowledgeable and helpful people active in the forum for example Kevin Gilmore, Kerry, JoaMat. Often the people who created the design will answer questions in the forum posts or people who have actually built one or even modified one. Unless you have lots of money/luck/ or existing stocks of obsolete components obtained from known good sources, I would stay away from any design which requires no longer manufactured transistors. There are many fakes floating around which can and will fail catastrophically on first switch on and non fakes are rare and there are few trusted sources willing to sell to non friends. I would advise reading the forum threads from start to finish and making notes, that way you can see the different versions/modifications emerge, see issues with certain components for example in the DIY T2 thread the voltages are high enough that some makes of resistor sparked and the insulation broke down.... Look at what people did that worked or did not work and learn from their experience. Finally if you can, give as well as receive. Post what works for you, post pictures, post updated bills of materials etc.

Finished! Thanks to KG, Sbelyo, Pars and mwl168 for the help!

I know this is an old topic, but I wanted to add some pictures of the latest sr-007 so that people can see if there are any differences. I did the blue-tac mod on the port and increased the spring to 105mm and flattened it as recommended. I inserted the spring as per the old -007 model as shown in the instructions (credit to spritzer for the instructions sheet picture). The difference in bass was actually quite moderate. It did help with bass response, but the change was subtle. Which is really all I wanted. No issues with the Stax fart at all so far. See attached. This was purchased Dec 15 2017 directly from Stax in Japan.

Anne Hache, 53.

PIP Billy Woodman, founder of ATC loudspeakers. One of the audio greats. Too early at 76 after long ill health. https://atc.audio/

RIP Ben Stelter, a 6-yo who died of Brain Cancer. As a hockey fan, it was incredible to see the impact he had on the Edmonton Oilers, and the love they had for him. Fuck cancer...fuck it hard especially for attacking such young kids.... https://www.nhl.com/news/ben-stelter-young-oilers-fan-dies-play-la-bamba-baby/c-335242756

Issey Miyake Dies at 84 https://www.nytimes.com/2022/08/09/fashion/issey-miyake-dead.html Missed this a few days ago. Of significance for me as Erika had an Issey Miyake dress as her wedding dress.