Do It Yourself

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…

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

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…

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.

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

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…

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

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

The part tested ok and seems to a 15 volt reg mc 7915ctg mc 7815ctg

The part tested ok and seems to a 15 volt reg mc 7915ctg mc 7815ctg Bottom right is where the reg were Below the vishey 4700uf caps

I enjoy thinking about different ways to accomplish the often-overlapping electromechanical goals of audio devices. Every few years I get to considering electrostatic headphone connectors, and every time I end up finding the same collection of vintage part numbers, shared experiences, and a few useful drawings that can be put together to probably lead to a functional socket or plug, if you want to make one yourself. I appreciate and have used that information, and now I'd like to consolidate it and create some actual specifications to help anyone trying to make a plug or socket. The most useful thing to start with would be plug specs. Pin diameter, length, pin circl…

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

Hi. I want to ask about Raspberry Pi Camera. I am absolute beginner. I want to make a project where Raspberry Pi camera send the image to the Raspberry Pi in greyscale and based on white or black, the stepper motor will rotate forward or backward. I want to ask, is it possible to make this project using Raspberry Pi or do I need to used other microcontroller also?

finally. higher signal to noise ratio, more than 110db. takes signals up to 20 volts peak to peak unbalanced, 40v peak to peak balanced. no input attenuator that adds noise for those stupidly high voltage dacs. ( requires 30v power supplies) (volume control in the middle) thd about .005% no feedback. work in progress 4 layer board. preamp2025f.PDF

The first completed DIY project in 3 years and in my new workshop lives! It's a battery powered Philips TDA1541A based stereo DAC, About 18 months ago I needed something to kick start me back into DIY after breaking down my old setup and moving to Florida. So I built a 10'x11' room in one of the garage bays and proceeded to slowly unpack. I ran across a few threads about the TDA1541 and became curious. This is what I settled on for the first try. It's on a test board I put together so I could mess with different power supplies and experiment with controlling relays to turn the power on and off. It's sounds surprisingly good! Very easy to listen to…

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…

9 years ago i started tinkering with the idea of a board to upgrade both of my SRD-7 to SRD-7 MkII, and then eventually a lot of stuff in my life went sideways and the project got shelved with a lot of other stuff. It did not work! it kind of worked. I screwed up something in the way the voltage multiplier was hooked up to the extent that there was only 26vac across the zener. I re-drew it yesterday. It's possible that aliexpress 1n4007 diodes were a factor. I'll use uf4007 sourced from mouser for the next revision. I know this shouldn't be hard. I'm kinda dumb for a smart guy. Sometimes i get a brain cramp. At the time, 9 years ago, my only high-bias stats we…

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.

I met Per Lundahl at Capital Audio Fest last year, and in trying to figure out what I could use I'd have for Lundahl transformers I asked about winding something that can drive e-stats, planars, low impedance, speakers from separate taps. I had also just bought a bunch of 6336B dual triodes, so thought that might work. The transformers came and many months went by but finally rigged something up. Basically right now it's just 6336B with both triodes in parallel, running about 200mA with a B+ of 260V. There's an e-stat output that steps up, and also 50 ohm and 6 ohm outputs. The grid voltage is set by a bunch of 9V in series. The black box in the middle on top o…

After almost ten years of loyal service, my KGST is starting to show signs of malfunction. Since last week I have a loud hum in the left amplifier channel. I replaced the tubes with another pair and readjusted the balance and offset. No hum could be heard and I could enjoy the music undisturbed again. The next day the hum unfortunately returned. Readjust everything and the hum was gone. After switching the amplifier off and on again, the hum returned. I have swapped the filaments, but that didn't solve the problem. I also left the gyro turned off, but that doesn't make any difference either. Hopefully someone has a good tip to try.

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…

So I want to print a holder for some supercaps. Anybody here disign in 3d regularly?

The speaker protection i have uses 2 relays for stereo channel (1 relay for each channel). But I'm thinking of using it in "mono-mode" and shorting the R+L input and R+L output to make it more "robust". Will that work? (this would mean I would need 2 devices for 2 channels.) Thanks again

As above. The 2 DACs I have already haa digital volume control which I believe are provided by the AKM/ESS chip. Thanks

For the bias voltage, I will be using a DC power supply I'm getting from Ebay: Bertan PMT-10C/N -1 kV 4mA Adjustable High Voltage DC Power Supply. Even though this supply takes in a DC input, the spec sheet says: "These fully enclosed modules are specifically designed with proprietary linear power conversion techniques to provide exceptionally low ripple and noise" Not sure how they can get a regulated high voltage from +24 VDC using "linear techniques", but in without using a switcher, but anyway, my question is: Is it necessary to ground one side of the bias supply? That is, connect it to chassis, U ground and audio ground? Is it necessary or useful for one …