Do It Yourself

Just some quick cables I made, 0404 breakout cable, XLR-RCA, RCA, XLR, Digital, mini-RCA, Adapters...

I don't know if this will be a good topic or not but what the heck, I'll shitcan it later if necessary. Basically, the idea is to post if you're having trouble sourcing a particular part. Not one you forgot to order, but something new that perhaps you haven't used before and you'd like input on. Example (and the reason I started this thread): I'm looking for an IEC module that contains a voltage selector switch. So far I've found 4 that I like, which I've listed below. #1: Digi-Key - 603-1149-ND (Manufacturer - 10SB3S) Pros: simple all in one, filter could be a plus Cons: voltage selection is not user friendly, don't need the built in power switch #2: Dig…

Hi All: Ignorant people like myself and newbies often need various technical advices and assistance when dabble in this wonderful hobby. Many of these are general topics that do not specifically apply to one specific device. These valuable advices and suggestions are scattered in various threads over time and difficult to find. I thought it may be a good idea to have a dedicated thread where these discussions and information reside. So I thought I'll start this thread and see if it gets traction. So here goes my first question - inrush current limiter and fuse. My thinking has always been that the main fuse need to meet two main requirements; 1. provide protec…

I'd like to see what cables (make and model) people are using in their DIY's; a good source (store) listing for parts would be nice too.

hopefully i cleaned this up and its the current versions of everything see updated links on page 5

So this started a few weeks ago when someone found a picture of my 100 watt night light. Its an 833A tube. (new picture below) And he wanted a megatron made from 8 of these. (10 vac at 10 amps each tube) so 800 watts filament power just for the output tubes. By the time you make the +/- 1kv power supplies running at 40ma, and the power for the 300b driver tubes etc, way past the limit for usa 120v 20 amp service which is 1850 watts. And with the top of the tube at silly and dangerous high voltage... bad idea. So i started looking for slightly less silly alternatives. I think the 211 tube fits the bill. running with +/-750v power supplies at 35ma. So a megatron with…

been working on this one a while, with all the popular transistors disappearing, I hope that this one won't go obsolete before the boards are out. I don't think so because Fairchild has said that the bc parts should be available for at least 5 years but onsemi said the same thing. This one is a diamond transistor input set, used as a voltage to current converter. A pair of Wilson current mirrors with input and output cascade as the VAS and a triple darlington output stage. http://gilmore.chem.northwestern.edu/cfa2.pdf if someone knows of better surface mount parts to replace the bc series, I might as well do that from the start. ft >150mhz, hfe &g…

I think there are enough woodworkers on HC to warrant a thread now. Between Myself, Milo (AKA Al, AKA DOTU), Naaman, Doug, Jeff, Marc and I know there are others. I thought it might be nice to have a thread to keep up to date on various projects, new tools, new accessories and new enovations. For example: A new enovation I find very interesting, is a new blade stop safety system from The Felder Group. Like the system from SawStop, it's immediate, and it drops the blade out of the way before any damage to digits can be done. Unlike the SawStop system, it doesn't use a sacrificial cartridge to stop the blade. Don't get me wrong, the SawStop system was nothing short of …

I bet everybody knew this was coming but we've been moving fast and the board is taking shape. If it's not clear from the photo then this is a massive slab, 16" x 12", so quite a bit bigger then the production version. It will be built like the BHSE with the board mounted to the top of the chassis, with the tubes sticking out of the top and the components on the bottom. Massive heatsinks are needed to keep this beast cool and a single angle bracket is used on each side of the board to connect all the parts together and make assembly just a bit easier. To honor the Stax legacy the following will be printed on the board: "With the utmost respect and admirati…

This one has been brewing for a while now but since I wanted to build a nice balanced amp it moved up in line. Basic setup is the same as the old Dynalo but now with Super Symmetry input, higher rail voltages and naturally a bit more power. Input stage changed to THAT340 which is a quad bipolar transistor array with matched NPN and PNP pairs. It is cheap and easy to source so no jfet drama. The other transistors are new as well and the pinout is different to reflect that. Here is a look at the new PCB design which is pretty much ready: It is 138*86mm. Another thing from the same vein is a fully discrete unbalanced to balanced circuit that we have …

This has been needed for a while. For those with problematic DAC's that put out a bit of DC, and balanced headphone amplifiers happy to amplify said DC and produce differential DC on the output... http://gilmore.chem.northwestern.edu/protector.jpg This is the one case where ti kan's protection board does not work, unless you want to use 2 of them.

updated Megatron schematic. If you manage to figure out what the stax mafia is doing, please let us know. We are having a hard time keeping track of it all

I did search but I couldn't find a dedicated thread about DIY electrostatics so in the spirit of getting the discussion started, here is something I've been working on. Well over a decade ago I bought up all the spare Sennheiser HE60 parts to assemble new headphones. The first thing to go out of stock was the main housing so to assemble the last pair, I had to adept a HD650 housing to take the HE60 drivers. Ever since then it has stuck in my head to make my own drivers for those housings and well... here is version 2.0: I bought a ratty old HD650 and completely stripped it apart. Headpad, earpads and cable went into the trash while the rest went for a l…

topping dx5ii schematic class B output stage. and they seem to be proud of this crap. discuss dx5ii.PDF

Where to buy a stax 5 pin female plug?

Saw some talk about this and decided to make a new version. use either the tube unbal/bal to bal board, or the solid state version result is about 125 watts rms into 8 ohms at thd of .005% will definitely drive 4 ohms with suitably large power supplies. transistors are standard pinout, so pick your favorite output transistors. the to220 transistors are mje15034/mje15035 perfect for so many things, including esl boost transformers. pioneera09.pdf

I do not remember I ever started a topic but I am here for a decade or more. I am playing with google AI for a time and I like it. I left out chatgpt so this is new for me. I liked to think I am good to search info from the internet but this thing is so much better. Specifications, go not go situations with some equipment so much easier to resolve. I was curious I asked to design a opa548 virtual ground circuit for me ( this is why diy) and I built it. Not so complicated circuit, I built it and almost worked. The problem maybe was the messy breadboard not the AI, a pin had to be grounded to stabilize the opa. I was a software developer, supporter all my time so I know thi…

after all these years we have finally found a solution for the power supply modules at a rational price. which means we can make a transportable electrostatic amplifier. similar to srmxh,srm252,srm270 etc. 3 times the power, +/-400v power supplys, no obsolete components etc. designed to be mounted to the bottom as a heatsink with silicone thermal sheet in between. should be about $250 in parts unless you go nuts with the volume pot. not sure of casing yet.

So as to stop spamming the stax thread, and get everything in one place. I recently got a ripping great deal on an SRA-3S in unknown condition. And since all of these are at least 50 years old, there is much to go through. There are some existing resources to link, and I will come back and add more as i scrape 'em together: It's a shame there are no component designations on the boards or schematic, so we'll go ahead and muddle through without them. Maybe I'll annotate some images. The area in the red box is the phono preamp. It's not much of a preamp. I hear you can pull the board and leave it out. An enterprising nerd could b…

Is there a balanced to unbalanced (single ended) board that is recommended? Twisted Pear has two options but they use op amps, and then there's the Broskie Cathode Follower, and Unbalancer Two. Those two use tubes. What else is out there?

I believe the old thread is gone, so starting a new one. A retrofitted power supply for a JDM Esoteric SACD player

In progress Amp design by me, power supply designs and circuit board layout by kerry, support by birgir +/-300 volt power supplies. complementary push pull all bipolar design with cmos style multiplying current mirror.

Hi All, I would like to mod my SRM007Tii so that it can use 6S4A tubes. However I am almost new in messing around with electronics circuit. Need some guidance from you all. Pictures below show my 007Tii board with re-routing & termination labels (Incomplete). I took quite sometimes to compare snapshots available online posted by Spritzer & Justin. All of them have slightly different wirings. The one I understand the most is the one Spritzer posted for the first time, so my preliminary outcome is similar to his one although it is still incomplete. Therefore I would like to clear my doubts before I start messing around with the PCB. This i…

As proposed, I started this thread for all to share your KGSSHV Carbon build experience and to exchange Q&A. This is a natural follow up thread to the Carbon Group Buy thread. Here are the version of Gerber files used for the boards in the group buy: kgsshvcarbonv5.zip (amp board) kgsshvpssicfetdual2new.zip (GoldenReference HV power supply, all-in-one version) kgsshvpssicfetsinglenewrightfat.zip (GoldenReference HV power supply, B+ and bias) kgsshvpssicfetsinglenewleftfat.zip ( GoldenReference HV power supply, B- and 7815/7915 based +/-15V regulator) goldenreference4.zip (GoldenReference LV bipolar power supply) goldenreference4plus…

These caps are extremely transparent in the many uses I did. Both high voltage 600 and 1000 volts I’ve used them in dc blocking and seem to have a neutral sound has anyone tried these in Amps and pre amps I’m curious to know what others think I’m not a fan of anything oil as I feel they color the sound. In addition in stat amp builds 400 vdc seems on the edge of max range why don’t builders use 1000 vdc rated caps ? ABD0000C255.pdf