Do It Yourself

I just boought a locky_z curve tracer https://www.ebay.com/itm/Locky-z-2019-Curve-tracer/114233327020?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649 Has anyone here used one or have experience with one? I was reading on another forum that the ones he's built with used parts sometimes fail. They're also swapping out the relays, electrolitic caps, op amps, voltage ref, and some of the resistors for better accuracy. I'm waiting on a power supply so can't use it just yet.

Can't seem to find any info or examples of these in use, but someone here must have tried them. I have found that buffers on the output of a Muses electronic volume control works very well and had good results with Sjöström Audio diamond buffers but Kevin's little PCB's might be even more compact. Can anyone remember a thread or post where these were introduced? They are a very simple circuit and could possibly do with some extra PSRR with caps right on the power pins, they are so compact I have found a neat way to stack them, in the pics below is a quad channel balanced stack, all the PBCs are connected through the power pins, leaving the i/o's separate. E…

I purchased this DAC from another HC'er in Canada down to the states but it looks like maybe he didn't get around to testing it out before selling it to me as it locks onto digital signals but provides no useful output otherwise. I only have a glimpse of the history of this thing but it's lived a rough life. I am positive old forum favorite NoNoNoNoNoNo is the previous previous owner and the work here is very very bad. Lots of WTF and cold solder joints everywhere and bonus scorch marks on some box caps, that odd white wire is a jumper used after he lifted a pcb trace... As a novice I have since cleaned this thing up as far as I can get it, at least at my skil…

Hey y'all, I've lurked around here for a few years but now I'm planning on getting started building amps, and I could use a bit of assistance. I've never soldered anything and I've probably stripped a wire once, so I'm gonna need to ease into this. From what I've read here and on Innerfidelity the Bottlehead Crack or Torpedo would be good places to start, as they're simple builds and pair well with my HD650s. Any other suggestions? I read this plan on getting the Hakko FX-888 as my solder 'gun' and 63-37 eutectic solder. According to tangentsoft I need small screwdrivers, small cutters and pliers, and a wire stripper. Are any other supplies needed? After this…

Hi STAX guys, first of all greetings from Munich, Germany. Within the last weeks i read a lot in your huge STAX Threads and learned a lot about the moddings that can be done throughout the hole STAX product line. But to be honest I lost control about the information I got. That is the reason why I opened a new thread. I own a STAX SRM-1 MK2 (early A-Serie) (my father bought it in 1983 when I was born 😊 ) and it has the very early number A5327. In the PDF you can see the wiring diagram which is for units beginning with number A5494 (so different from mine). The unit was not in use within the last 20 years and I already replaced the electrolytic caps (Nichicon LKX…

Hi new to the forum and I am interested in building a kgsshv or kgsshv carbon. I have done other projects from amb.org built a beta22 / lcdduino / volume control system. I am unaware if there are any guides or published places to get information on where to start these builds / parts lists? I have found the circuit board gerber files and I am guessing I have to send those to get my pcbs manufactured? But I am a bit confused as there are many versions and variations of build files. For example I see Kgsshvcarbon v1-6 and along eith them left / right / servo / ground. Any advice would be appreciated.

Has anyone built this balanced beast and tried it out?

Well cheap compared to all the monster amps out there So correctly done, one would do the Uberamp2-Raal edition, which results in something really big,heavy and lot of heat. And a custom and large chassis, and a pile of $$$ This is a bit cheaper and easy enough for just about anyone to do. From the Ti Opa541 datasheet, showing paralled opamps good for at least 7 amps rms of output into anything including a dead short... Designed to be mounted directly to the heatsink, amp board right angle to the heatsink. All wires to the board directly soldered, 4 oz copper highly recommended. Power supplies are a minimum of 24V at 10 amps, like this, but more …

Hi all, I purchased a KGSSHV recently, and whilst overall i'm very pleased with the sound, the pot installed is cheap and unfortunately has some balance issues at lower volumes. It looks to be a modular type pot, and bizarrely has 4 lugs per channel rather than 3. I've managed to get hold of what I'm told is a rather nice TKD 4CP 2500 pot, which has three lugs per channel. Can anyone offer some advice on the correct way to go about wiring it in? Looking at the old pot, there looks to be a set of bridged lugs on the far right which go directly to a piece of wire bridging the inputs at the back of the amp, as well as left/right input and output wires from t…

As many of you know, I for one have stopped releasing all new designs for a few years now after I got fed up with people building crap and claiming it was somehow connected to Kevin or I. Now this also means I don't release the PCB's for many of the older projects as I want to change something and often... make them smaller. So this hasn't stopped people selling crap with our circuits but at least they don't get any of the updates. Now here is an amp I saw come up for sale in Japan a while ago. The new owner contacted Kevin to try and trouble shoot it but yeah, we don't offer any real help with these things. Something about the PSU did peak my interest so when …

For the Carbon I am building, the user would like to be able to bypass the volume pot, but would like it switchable for when the source doesn't have a volume control. I had initially told him no problem, this will be easy. The more I thought about it, I realized it isn't quite as easy as I had surmised. Simply shorting the input to the output (wiper) would still result in potentially bad things depending upon where the pot was in its rotation. Since I had already done the pot adapter boards for the gb awhile ago, I started with one of those for pcb layout (the pot I am going to use is a TKD CP2500 4 channel). My initial thought was to take the pot completely out…

Does anyone have or know where I can find a board that would let me mount a single or side by side Amveco PC mount low profile toroidial transformers? I'm just looking for a board that would have AC in and out going to terminal blocks and allow the use of standoffs. Amveco PC mount low profile 50VA toroidial transformers https://talema.com/wp-content/uploads/datasheets/70000K-72400K.pdf If not, I'd gladly pay someone for their time to lay out a board for me. Something like the pic in here

I published a modification for the Stax SRM-T1/T1S/006 in AudioXpress July 2017, which is just out. The modification adds 5.1 kilohm output safety resistors and cascoded constant current output loads, which with their heatsink fits the space vacated by the plate resistors - see photo. Spritzer did something similar a few years ago with an SRM-007, adding constant current loads, but he also changed to 6S4A outputs. Unlike plate resistors, constant current loads burn up practically no signal current, so while the stock amp burns up 9.2 mA signal current in the plate and feedback resistors at its specified 300 VRMS maximum output, the modified amplifier only …

I have had my beloved ATH-L3000 for many years now. It has developed a frayed cable around the split: I am seeking advice as to possible next steps. Right now, it is not causing any performance issue (has not broken connection). As a safety measure, I have wrapped the entire junction with some blue painters tape to hold it all in place - not ideal. Questions: Is a replacement original cable (NOS) available? - checked with AT - they had no real response - said send it in.. Try to repair the junction? - not much room to work and secure. Is a compatible replacement available (equal quality)? Possible third party cable replaceme…

Hello everyone, hope everything doing very well today. Few days ago I found two transformers in my dungeon, which named by my wife. I mentioned it has 16V out and double 110V in, so I guess perhaps could make something like stax srd-7. Then I made a pcb and give most places to voltage doubling rectifier, as same as srd-7, and... it works. Well somehow the bias unable to reach 580V, only around 490V, the sound quality, of course, bass section bit weak, so I have to turn the EQ on, then everything fantastic. BOM: 2 30W transformers 110-0-110 in 16V out, 1 50W transformer 220V in 110V out. 1 fuse @200ma 6 0.1uf 630…

Nectar Sound, purveyor of the Pollinator and now the Hive headphones, has a DIY amp published on the website. I reached out and picked up a PCB so I can build this low cost energizer and see how it stacks up against my SRM-252S. Attached is the schematic, BOM, image of a completed amp, and hook-up guide. You can also access everything on the Nectar Sound website. Sajeev has updated the board slightly from the images attached to hold a pair of CL-90 inrush limiters to prevent blowing a fuse on start-up. I'm in the process of gathering the parts now, but wanted to post this to archive the build and see if anyone else was building (or has built) one. Nectar1p0_Headp…

Is this the new product for high voltage transistors ofr electrostatic headphone amplifiers? https://www.akhansemi.com/company.html

Edit: I've started collecting payments. Information is here Enough people have expressed interests where I am organizing a group buy. Here is the link to the spreadsheet to register interest and what you would like. I can also include mounting hardware for the XLR jacks and other parts. I plan on going through enclosuresandcasesinc.com and using their 175DT desktop case. I priced a custom length 6.8" case without any cutouts or finish and it was around $30 each if I bought at least 10. Currently getting a quote for machining and anodizing but it doesn't seem so bad if I get enough people. Here is what I've drawn up. Let me know if there's any egreg…

Folks, I replaced all the electrolytic capacitors in my SRM-600. I can't say for sure if this has happened before, but this (photo) capacitor at 10V 4700uF is heating up. Not very much, around 55C. The headphones aren't plugged in. Can you tell me if this capacitor is in normal operation? Does it have to warm up? My SRM-600 for 230V voltage. First, I supplied a cheap Jamicon TKR472M1AJ26 capacitor. It was heating up.Then I decided to place EEUFR1A472L Panasonic Low ESR capacitor. However, it's warming up, too. I checked the diodes next to it - they're not broke. On the cap about 7V. Any other caps running cold. Only 4700uF/10V run…

Anyone here have experience with one of these? Price is right, but likely too good to be true? https://volumio.org/product/allo-stepped-attenuator/

Could someone post how to do this, or a link?

Wondering what type of plastic Stax uses for the (black) jacks on their amps. Or if anyone knows of a black plastic or material that is machinable and plays nice with high voltage. I don't know what Stax uses, thought it might be bakelite as it is hard and brittle but it fails the "409" test for bakelite and a sliver that I cut from one floats as well (bakelite is heavier than water). You can sometimes identify plastics by the way they burn. Couldn't ignite the (tiny) slivers that I had. Possibly a phenolic smell after heating, might be a lower density resin related to bakelite. DIY jacks are usually made from white teflon (or delrin). Black coloured materials t…

Keeping in mind Kevin Gilmore's design rules i have insomnia about stabilizing common mode of JFET input stage without sacrificing CMRR or straight referencing it to the amplifier/source ground. So, check attached schematic. While keeping straightforward signal flow aka "Gilmore's gesign rule" it also have second control loop which helps SuSy amps to maintain output common mode near ground potential.

Anyone has experience with the Ebay kits for the KGSSHV Carbon: https://www.ebay.com/itm/Power-supply-PCB-for-KG-Kevin-Gilmore-KGSSHV-CARBON-Electrostatic-amp-L9-50/123415369465 and https://www.ebay.com/itm/Kevin-Gilmore-KGSSHV-CARBON-Electrostatic-Headphone-amplifier-bare-PCB-L8-39/123327894674 The names contain "L9-50" and "L8-39": are these version numbers ? I'm interested in building a KGSSHV Carbon and any help is appreciated.

Hope you guys don't mind, but I'm taking the liberty to collect some info, links etc. here. 900V floating supplies 350V/us the cole slew (couldn't resist) seems to be happening in bits and pieces in multiple threads on multiple forums and there are some implementation issues which seem to be worth discussing...namely fitting all of this somewhat daunting amplifier into one case. I guess at some point Kevin decided to split the input and output stages- output board output schematic The output stage features the floating supply floating supply fboard floating supply schematic the input/driver board As of today the aim is to fit this all in …