Do It Yourself

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…

Tonight, I'll be making some new ear pads for my new vintage electrets. The electret arrived with ruined pleather pads. No pleather left, only uncomfortable fabric. As a downside, the fabric ruins all the deep bass. My first attempt to restore the pads wasn't a success. They ended up a bit too small for the baffle. I'll be making them (or try to make them) with a bit bigger diameter, to reach further out on the baffle. They are to fit onto here: And the old pads measure like this:

Is anyone familiar with this "hacker collective"? [url=http://www.nycresistor.com/]NYC Resistor

I have some of these Chinese "CMC" type RCA Jacks. They have a knurled ring that has indents for some type of PIN wrench. What do you guys have for these to keep them from getting scratched up via pliers? PIC

Ok, I have a quick question. So, I have some of these sockets, with brackets: I need to somehow embed a nut into the bracket, so I can then secure them to the top of the chassis. I won't have access to the bottom of the socket. I don't know much about PEM nuts, but I was wondering if something like that might work. I'm leary to try an adhesive, or soldering, etc. but maybe it might work, but I'd prefer a better solution. If someone wants to make me a bracket, that's a different story, but let's assume that's not a viable option either.

http://www.ebay.com/itm/322416989057?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT Looks real in the pic and has a pic of a lockyz output from the curve tracer. Gets good feedback and all. Still no real way for me to tell from the pics. I was hoping to buy a set and ask one of you more experienced users to test them for me to see if they meet original specs.

I just bought some copper tape off ebay. Soooo...what should I tape with it? Biggie.

I've been lending a hand with board layouts for a few projects, notably for a build of Kevin Gilmore's DynaFET design, and doing so made me realize two things: (a) there aren't any DIY projects for amps with a truly high-end feature set, and ( I want one, but I can't really afford it. The DIY crowd has some amazing analog designers and has produced some really astounding designs, but the supporting and surrounding circuitry often isn't much more than a pot and maybe a selector switch, and sometimes a power LED or relay control circuit. There's so much more that could be done to make amps more convenient, self-monitoring, and just plain nifty. So I decided that this was an…

Given the outcry for some documentation on how to build some of these ESP amps I think it is time for a thread on the subject. Now the plan is to post here a summary of the parts needed to build a KGSS amp using the boards from Headamp.com plus what ever build/mods of Stax amps come to mind. KGSS Now for some time people have claimed that the KGSS is somehow hard to build when it really couldn't be further from the truth. My first DIY amp was a KGSS with those horrible old PCB's using offboard heatsinks and caps but after blowing up a couple of boards and PSU's (I really didn't have a clue as to what I was doing) I had two working amps. Now the new boards make …

hi! i'm new here.. i'd like to ask for some help. diagnosis and repair.. i have a A4tech hu-200 usb headphone. now it only plays the right channel.. but before that happened i noticed that the audio is like panning from left to right til it could only be heard in the right. i researched about repairing headphones and all i saw is that the problem could be a loose wire or something similar but when i open my headphone there were no loose or broken wires. what could be the problem? and how do i fix it? i don't wanna send it to a repair shop cause i wanna see if i could repair it myself.

I ordered some of those teflon 9 pin sockets off the eBay user many here have used. They look fine but I've not used 9 pin teflon before, at any rate getting a tube in one is extremely difficult. I can remove an individual pin and put it on pretty well, but leveraging all nine into the socket is a nightmare, I can't imagine trying this with a soldered socket. At least when unsoldered the pins have a little play to align themselves. Other experience? Do I actually need to pull all the pins, try to use and pre stretch them before use? Ugh ...

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 …

Hey, I was thinking about using the 220 taps on the primary side here in the US in order to half the voltage on the secondary side of a transformer. Can anyone think of any reason not to do this?

I forgot to order the fusedrawer for a DD12.9111.1111 shurter IEC inlet. The part number I'm looking for is 4301.1405 Does anyone have one of these fusedrawers they don't need right now? If not is anyone placing an order with mouser soon that could order this one for me? The mouser part number is: 693-4301.1405 Thanks in advance, Manuel

This concept has interested me for a while now given just how simple the amp could be made. Just two tubes per channel and then a phase splitting output transformer makes for a stark contrast to something like the T2. Now whether this simplicity is better or worse isn't the issue for me, I just want something different. I figured it was time to get the concept of these amps outside of the random thread on HF and PM's. I've been talking to Frank Cooter about this and given how happy he is with his D3a/KT88 amp I'm going to try something similar. I'm always a fan of using what I have (hence my Exstata is a bit different from all the others) so soemthing like the …

Well its done K701 recabled with Mogami 2534 Neglex Copper Quad Mic Cable. Nate had a supply of it, along with the black 3/16" Nylon Multifilament techflex, so I asked him if he could strip the jacket and shield off the Mogami, and feed it through the techflex, which he graciously did Here are some pics (some not so good) of the job: Stock cable Mogami laid into the K701 frame Preparing the 4-pin XLR end of the cable A happy ending On the other ear phone there are two small wires which I have not replaced, but I may leave them for now.

A mate at Auriculares posted the link to this article which may be of interest for you DIYers. Not being a DIYer myself I found it interesting nonetheless.

I know almost nothing about capacitors, but have it on fairly good authority that the frequency correction network on my old ESL63's uses an old Electrolytic-type capacitor which is not particularly good for this function, and should be replaced with a Polypropylene version at the same capacitance (220uF). Excepting the vast difference in size between these two types, what brands am I looking for? This cap is in the signal path, so quality is of the utmost importance. Voltage rating shouldn't be lower than 250V. It doesn't necessarily have to be a single 220uF cap - two 100uF caps will do the trick, and might be easier to place in the housing. Thanks for your help …

I'm venturing into cable making and I've found sources for everything I need, except good quality copper wire. What should I look for? Thanks in advance! .

I didn't find anything in search, which was surprising. Maybe I suck at searching. Anyway, a couple q's for those that own one or more: 1) How do vintage ones hold up? How often do they need recalibration? I'm not talking about serious vintage, with 50 tubes inside, but 1970s to 1980s solid state stuff. 2) Specific brands to look for/avoid? 3) What's the cheapest decent digital oscilloscope that can be hooked up to a PC? This or something close to it is what I'm used to using in the labs (yes I know it's a couple thousand... used): Digital Phosphor Oscilloscopes: TDS3000C Series > Data Sheets : Tektronix Specifically TDS3012B. 4) How useful/not useful has i…

I wanted to re-terminate an HD650 cable to 4pin XLR. What is the best way to strip off the black sleeve without cutting one of the tiny wires? I was trying to carefully clip it with small wire cutters but I keep snipping one of the little wires. I also tried a wire stripper and that was worse. Will it make much difference if one of the wires is not connected (as long as the majority are)? Also, I see that the HD650 cable doesn't have shielding so I assume one doesn't anything to the 5th metal connector.

Has anyone tried to better this thing ? Any ideas?

My HD-600 is one of my workhorses and I love them. Lately I have been having trouble with the right channel going in and out. I think it might be a bad contact with the wire but I am not sure. Any suggestions or anyone willing to take a look at them for me?

So, I have some nice shiny TO-3 transistors. I'd like to make a PCB with these as output devices and some sort of way to transfer heat via flange that I can mount to a heat sink. I have to admit I've never used this package, so I'm curious.... assuming I cannot mount the can on the fin side of the heat sink (which would require way to much milling and effort), what sort of ways are there to deal with this? Second question, and not at all related to the above... any recommendations for a relatively low voltage CCS? Let's say 60V and 3A or so as extreme parameters. Thanks!

I've started up this thread to give folks a place to offer their time/parts/labor whatever to help Icarium get his SP amp up and running and with a little luck maybe even sounding good. Hopefully this thread will to organize the effort that I'm sure has already begun via PM's. If your unaware of Dan's situation: