Do It Yourself

Looks like Heath kit will be coming back to business. Source Has anybody played around with heathkit's stuff back in the day?

I bought a replacement tip for the iron labeled Aoyue brand but seller claims works with the Hakko. When I replaced it in the iron the replacement tip spins sort of freely (I can rotate it with a slight bit of force) even with the nut for the protective metal guard screwed in as tightly as it will go. Is it supposed to do this? Thanks guys.

Thought some of you guys may be interested in these if you had not seen them. http://toolguyd.com/...-storage-boxes/

I've posted this already on another well-known headphone forum, here however I see DIY is more prominent. I'm thinking about bying an used pair of ESP 950s and seriously modding them. I've considered making a totally DIY ESL headphone, but making the headband and enclosures for them is too much for my limited skills. Kosses though seem to be a fine ESL headphone as they are, and from pictures of their insides on Wikiphonia it seems that there are some mods easily possible. 1) Removing damping and maybe adding 'phase corrector' like on old Fostex T50 - a felt ring which suppresses high frequencies coming from outer parts of their drivers to even out phase and f…

I know that AMB has his Arduino-based system in the works, but I'm at a point in my EE education where I want to design something myself. I'm thinking of the following high-level scheme for a 4-input, 4-output audio switchbox. TI MSP430 microcontroller LCD display pushbuttons ADG1604 analog muxes My question to the other EEs on Head-Case is this: most all of the electronic switchers I've seen so far in the DIY realm use relays. Is there any major downside to using analog muxes that I haven't realized yet? Any reason that I shouldn't pursue this technique? I was wanting to try something that I haven't seen already, and this seems like a very do-able project for m…

Hi folks, the Soldermizing itch has started again...I am in possession of a Stax SRM-1/Mk 2 "energizer" that, apparently, is in perfect working condition. Still, that is no reason not to f*** with it! Elsewhere, here or on one of the other "headphone" sites, I found guides to such things as re-biasing the unit (mine is a tad off), and thanks to (uh...) the person who pointed me to a schematic of this unit. The SRM-1 looks fairly basic and is within reach of my admittedly dodgy soldering skills. I would like to, at minimum, replace the power supply caps. Also, there are 13 (to my count) little caps that could be replaced. I would like to replace them with good q…

That's right. A few upgrades and tweaks for the old gal. On the list will be opamps, wiring reroutes and upgrades, power supply changes. First up, I'm going to remove these JRC4735B opamps (assuming I have correctly identified them) and replace them with...dunno. After reading up a bit it appears that these are part of the problem with this player sounding so dark. I'll have to do some comparisons, but it seems like an OPA2134 could be a candidate, or an AD8610 (or 20). Guesses? I'll have to check the pinouts to be sure.

I would like to thank "DefectiveAudioComponent" for his excellent DIY tutorial I did the same as 'practice' for an old pair of Sony and got ok results. Recently, I have gotten into headphones in a big (but somewhat cheapskate) way...I now own two pair of older Stax Lambda (one normal, one Pro). While all seems to be in good shape, save wear especially on the head band, I thought it would be nice to have real leather pads. I know that real ones can be had via Stax (Ebay) but pricey ... around $100 or so. After finding the above tutorial, I said, why not try it on the cheap? Liek the original author, for this 2nd project, I got scrap leather off Ebay (black, …

Hi guys, Been wanting to build this for some time, and was considering a M3 and σ11 to drive some home made computer speakers. I'm leaning towards a nice 2ch set of full range speakers. Based on the microFonken design. Its been awhile since I've done anything on this scale, as such, it would be much appreciated if I can get some advise/opinions/correction on the attached BOM. Cheers in advance

I have a few uses for a simple, regulated power PCB that supports a number of different ~25VA PCB mount transformers with a bit of filtering on each side of the transformer. I'm trying to nail down the schematic a bit and wanted to see if there was any advice out there

I assume frontpanelexpress.com is who I want to use if I want a 3.5"x2" engraved faceplate made for my amp? I'm messing around with their software right now, any tips? Thanks

Has anyone ever reterminated a Cardas Sennheiser cable for the HD650? I'm thinking of buying the Fat Pipe version that HF sells in a 10ft length terminated with 1/4" TRS and then cutting that into a 5ft cable and re-terminating it in a 4 pin XLR. I want to know if the cable is laquered inside and if I have to melt the insulation off of it to solder the wires. Then I would make an extension cable and 4 pin XLR to 1/4" TRS SE adaptor with the rest

ok, I'm finishing up a Twisted Pear Buffalo DAC using the soon to be released Legato III I/V output stage. I intend to use the BAL/SE stage in the beginning since all of my headphone amps are single ended. However I want to build a balanced headphone amp. It will be the balanced dynahi or M³ and I'm concerned about the statement below from Twisted Pear. What does this mean if I build a balanced M³ or dynahi rev2?

Here a video guide I made on how to make a LOD, hope it will be of some help to some.

I'm trying to learn MAGIC which seems to be the most popular open source VLSI layout program. Feel free to post anything relating to VLSI layout in this thread, perhaps something you bring up will be of use to me and others. Currently wondering if there are any other good programs, open source or not, and if there is something more GUI than command line based. I'm currently trying to run MAGIC off an SSH connection to my school's Unix server and it's giving me troubles so I'm going to go home and try it or just install MAGIC on my computer. Any good tutorials or examples would be nice as well, I'm currently following a set of tutorials by John Ousterhout.

So a Nugget B22 that I recently bought from penger died at a local meet yesterday - I walked up to the amp while someone else was listening (more likely trying to listen) and noticed that the amp was off, which seemed odd. The power switch did nothing and re-plugging the cord did nothing either. One day later the amp still doesn't power on so it wasn't temporary either. I verified this amp as working before the meet, and it worked when I set it up at the meet too, as I listened to some music for awhile on it. I hear absolutely no internal noises when depressing the power button and have no idea what caused this and no idea how to fix it either. (Edit: the power button …

Hello Head-Case I am working on an amp using this transformer in a PP output from a 6h30 tube. I would like to know if anyone has had experience with wiring the secondaries in various series/parallel configurations as indicated on the datasheet for different stepdown ratios to drive different load impedances The schematics & articles I could find which use this transformer for headphone use (the Raven, and a few from Andrea Ciuffoli) dont make mention of using the secondaries this way, where other a few others with sowter & "unknown to me iron" do. I think its something worth exploring, but would like to know ahead of time if its a waste of time.

Oh, the number of times I have mentioned how much I like Steve Blinn or Adona rack designs! Extruded aluminum exudes strength and elegance, gotta love those T-slots... but, the price, yikes! Well, in my never-ending quest to one day build myself something along those lines, I came across this little gem of a site: http://www.framexpert.com/ What's so special about it? A FREE download program that lets you build whatever you want using the t-slots. I've been playing with the erector set for about an hour now and it is pretty easy to use, especially given the fact that I have no experience with 3-D software whatsoever. It even provides a cost estimate of your build a…

I've been messing around with a Counterpoint preamp I have owned for several years on and off. It's always had a slight amount of hum, not real bad, but it bothered me. Over the years I've managed to make it worse, and then much better, but never quite gone completely. After dealings with a couple of former service techs on diyaudio, I finally decided to try once again to rectify this. I was prodded to look at the PSU, particularly the heater supply (I'd already done some work and parts replacement in the HV section). Looking at the heaters, I had recalled seeing some ripple on them back when I rewired the umbilical (both before and after). About 50mV of r…

Does anybody here have any experience with hot air rework station soldering? Anything to look for or avoid? And, how does this compare to flood and suck or toaster oven soldering? I was looking at this one as being in my price range and having generally good Amazon reviews.

I'm taking a Microelectronics lab course and we need to pick a particular not overly complicated circuit we think is interesting that is in the literature to build and test. If necessary, we are allowed to make use of the VLSI fabrication laboratory but have to design the layout ourselves. Any cool ideas people have for this project? Edit: Forgot to say that unless we provide the transistors/opamps/etc ourselves, we are using bog standard parts. 2N390x BJTs and ancient 4007 MOSFETs. Opamps are some newer version of the 1458.

I have the boards from Justin (KGSS and BH power supply). I'm having some trouble locating a BOM for both, a circuit diagram and a parts overlay image. So far, all I can find is this: http://gilmore2.chem.northwestern.edu/projects/showfile.php?file=gilmore2_prj.htm Any kind souls care to point me in the right direction?

They used to do it for classrooms, and I have a similar program for 16 listeners. I'm on a small budget and can't afford a headphone amplifier. I want to use an old stereo amplifier of about 5-10 or 20 watts (which is really two amps in one box) on a TV output source. A switch on the panel will unify the stereo to mono left amp, and right amp. I have a Telex model 753 mono passive headphone splitter with 8 each 1/4" mono inputs, for one channel, and parts to make an identical splitter for the other channel. (there's not even so much as a resistor in the box, just wire and phone plugs) Now, with two splitters on Left and Right speaker output channels, I plug in up to 1…

Schematics and photos attached! I got my belated Christmas present from Justin the other day, a lovely KGSS amp. Finally I got to hear my new Stax 007 Mk2 (Omega 2) in all their glory. Knowing that I was going to install my own Goldpoint 1 dB/step attenuators, and a Left to mono switch (to check headphone balance), I asked Justin to agree to construct a KGSS without wiring the input connections to the back panel or installing a volume control (yes, he did test and burn in the board). Leaving me with some fun to do on my own! The first thing I discovered is that the KGSS is extremely sensitive. I judged it has at least 15 dB too much extra gain, even with consumer (nomi…

So for various reasons that i won't exactly go into, i'm about to have a bunch of surplus stuff looking for an application. A bunch of programmed test sources signal generators. computer controllable. All phase coherent to the master reference source. http://www.programmedtest.com/pts500.html 3 x 1 mhz to 500 mhz generators 1 x 1 mhz to 620 mhz generator with dual outputs that can be inter-modulated 3 x 1 mhz to 300 mhz generators one with dual outputs that can be inter-modulated And some CW capable class A RF power amps 2 x 200mhz to 500mhz 50 watts 3 x 10mhz to 200mhz 300 watts As i said, looking for an application. So i contacted craig who is on…