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…

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…

Hi all, I'm going to do a board run for Dr Gilmore's latest projects (KGSSHV, Dynahi Rev A and DynaFET) so if anyone is interested, please sign up here. The KGSSHV will be the latest revision. Board set would be 2x amp boards and 1x PSU board. The amp boards are now mounted on side heatsinks. http://gilmore.chem..../kgsshvps8e.jpg http://gilmore.chem....gsshvampv7s.jpg The Balanced Dyhahi Rev A and DynaFET will share the same PSU. One PSU is enough but due to the symmetry, 2 would surely look better Board set would be 2x amp boards and 1/2x PSU board(s). http://gilmore.chem....u/dynahibal.jpg http://gilmore.chem....ynahifetbal.jpg http://gilmore.chem....…

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

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 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…

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?

Like i don't have enough projects going on at once I'm tired of waiting for someone to release boards that do this right. so here is mine in progress http://gilmore.chem.northwestern.edu/attenuator2.jpg Because i don't like any standing power on the relays, and i don't like the resistive drive either, this had to be a bit bigger. board is 3.4 x 10 inches. stereo single board, or two for balanced.

Lil knight among others have asked for an updated dynahi board. Here it is. http://gilmore.chem.northwestern.edu/dynahi8.zip changes, remove 2sk389,2sj109, add lsk389,lsj109 2sk170,2sj74 you can use opa445 instead of op27 and then you don't need the 7815 and 7915. 2sa1349,2sc3381 can be replaced with the single versions. I need to check this a few more times. unbalanced input, balanced output version coming soon.

So a couple of people have asked for a discussion of the design elements of the T2, and any observations and improvements that are possible. So as not to polute the T2 build thread, which is already seriously poluted, the discussion of T2 design elements, including kerry's dynamic amp should go here. doug wadsworth (wadia) should be stopping by soon Actually, a moderator change the thread title to discussion of the T2, and other circuitry as we see fit including but not limited to my other designs and shunt regulators and stuff like that etc...

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.

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…

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'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…

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?

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.

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…

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…

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…