Do It Yourself

Kevin, While surfing I came upon these instructions for Balanced Power Transformers. http://www.geocities.com/jonrisch/catch2.htm I was wondering what your thoughts were on his directions? I also am curious about his comments about Toroidal vs I-E and how I shouldn?t have used a Toroidal. His Comments Thanks Yikes

This is something I've been playing with for a while, in short, I can change my K340 from sealed to vented so I have more range for tuning the bass. This picture shows how it's done. Sealed the back with a piece of plastic and taped it in good with electrical tape, but first I put a couple holes in it which I've highlighted with the arrows. How does it work? Well, you can plug one, both, or none of the holes with a small piece of blu-tack, and that'll change how the bass sounds. With the holes open there's more bass but it isn't as tight, you get a bass hump but it doesn't really go any deeper. Close up both holes and the bass gets tight, maybe a bit too tight so i…

Just fyi: RadioShack Recalls Power Supplies Due to Electrocution and Fire Hazards

I moved this from the build gallery thread cuz it was getting too far off topic. I am playing around with a Rotel 991 CD player and was going to replace the exisiting I/V stage with THS4031 and AD8599 buffers. My plan was to use Aries adapters and socket the opamps, with Pana FM 100uf caps as close to the V+/V- pins, and somewhere in the area of 1-3.3nf across V+/V-. I had removed the stock opamps, so I put a std. Mill Max socket in one of the I/V spots, and put the Pana FMs on the bottom, going from pins 7-3 (V+) and pins 4-3 (V-). The board has a top ground plane which would be a better spot to run these too than pin 3, but I felt I could get the caps closer to the …

Does anybody have a source? All I see so far is chassis mount.

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 …

I have a couple of DIY questions: This one is pretty basic. I need an easy to use, lead-free solder. I'm guessing a lead-free eutectic solder is what I'm looking for. Is this correct and do you have any recommendations. Also, please recommend a source for it. Not that I'll be needing this information in the near future, but I have a question about Magnequest. I see a lot of other brands talked about here and almost no mention of this one. Are Magnequest not great transformers? Or maybe there is some other problem with them or the company? Or lastly, maybe nobody here uses them due to habit? I'm just curious as I know that Bottlehead likes and uses them.

I spent the better part of last weekend researching amps for a new pair of headphones. Reading other people's reviews and seeing their pics is fun, but figuring out whether the amp outputs enough power or if the damping factor is >= 8, well that's tedious. So what started as a few formulas on paper eventually (over the span of a week) turned into a website that calculates all this for you. It's a tool I built for myself, but I hope you'll find it useful too: www.audiobot9000.com

I and a few others have decided to get the new bipolar version of Blue Hawaii PCB made by PCBnet in US. I used PCBnet for the Carbon GB in 2015 (and other occasions). Their price is higher but we’ve had great experience with their board quality. The boards will be 2mm thick and 4oz copper, green solder mask and white silkscreen in leaded finish. The cost of boards is $30 USD for a set (two PCBs) if we can get 15 sets made. You’ll need to add shipping from me to you for the total cost. Kevin released this latest version of Blue Hawaii in early 2016. I worked with Kevin to trace the board and at least one headcaser has built one working amp with them. This …

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.

Aside from Alps RK-50, are there any quality quad potentiometers? I'm just curious if there are any others out there.

I've been getting back into guitar lately and think I'll want to put together an amp relatively soon to replace the cheap starter I'm using. Anyone have any ideas on a good one to put together?

Time to make some cables. I want to cover them in the soft nylon stuff. What sizes would I need for the following: 1) 4-conductor 22 or 24 AWG braid 2) Over regular Mogami Thanks!

ok, I have plenty of stuff that needs to go. Perhaps you do too. I'm open to all offers and if you're patient, I'll probably just give it away. Once this stuff goes, I have another list... so.. no prices, please make an offer. Pair of unopened, and unused ports. These are the best ports money can buy I suppose: Measurement Mic Preamp boards and Zen Headphone amp boards: A collection of Brown Dog adapters: Turntable motor pulley: Random component video cable: Mogami headphone cable: Onzow Zerodust, barely used: Twisted Pear Audio Ballsie, first generation I believe: Chinese Softstart Board, works great: A pa…

Hi all, I`d like some advice on the helpfulness or futility of wearing gloves while soldering (some suggestions of gloves to get, if useful would also help). Also are there any practical solutions for newbie burn prevention while learning to solder ? My head will be behind a thick lense when soldering so goggles aren`t a concern and there will be a strong flow of air to remove fumes from my vicinity. The most likely soldering station I`ll buy is a Xytronic 369 the same apparent model is labeled as a 379 in America. Rapid Electronics - Auto-temp 369 soldering station

Hi, I think I know the answer to this but I'll throw it out anyhow. I have some DMMs and would like to know about what you guys do with respect to calibrations. So I'll use 2 of my DMMs as an example. Fluke 87 and NEW VC99. I put them both in an electrical outlet at the same time and they both show the same V. The Fluke I bought around '96, the VC99 is about a month old. My plan is to measure some caps, resistors, etc and see how much they agree. So far the voltages measure the same. I'm not sure what it tells me if they disagree, but I thought I would just play around with a NEW meter and my Ol' Fluke. I may just send off the Fluke and get it calibra…

I'm about to give my M^3 a major overhaul - new enclosure, sigma 11 to replace the current tread power supply, and a possible cap upgrade. I've never found myself using the bass control much and am considering removing it. It's removal would seem to remove 1 pot and a few caps from the signal path, which might be a good thing to do, especially if you don't see the need for constant bass adjustment.

A really good article by Nelson Pass on class A, A/B and B operation... http://passlabs.com/pdf/articles/leaving_class_a.pdf

I thought it might be kind of helpful to have a thread of your least favorite parts so everyone else can avoid them. For me, right now it's the Switchcraft TA3F mini 3-pin XLR connector for AKG headphones. Piece of crap is made of metal and bad plastic and is breaking/falling apart on me. But there's no alternative available

Hello all!! This is my first post here and was hoping that you DIY'ers can help out a noobie. This will be my first attempt at making a headphone cable and would like to know if this is the way to go about it... Unbalanced cable using a 1/4" TRS plug and 2 mini 4-pin XLR's for the headphone end, left and right. Is this the correct way for wire hookup? See diagram below....

Hi, everybody! I'm novice here and signup being impressed mister Kevin Gilmore designs. First of all - thanks to him for making designs opened! Now i'm thinking about building Dynahi at a different manner than author. The main concept is to put overall amp in a comparatively small case such 3209: http://m.ebay.co.uk/itm/3209-class-A-Full-Aluminum-amplifier-Enclosure-AMP-case-both-side-heatsink-/271986781371?nav=SEARCH So, PCBs must be rerouted. Here i want to offer another building idea, best to understand by photo and renders (for understanding dimensions - caps are 18 mm diameter and 35 mm height): There are several benefits in such layout. 1.…

Hello, new to Head-case, but an experienced elec tech. After demoing a friend's, I'd like to build a balanced Dynahi, but am having troubles tracking down documentation and boards. Can anyone steer me in the right direction? Thanks!

For those that have not been following Tangent's thread on Headwize. http://headwize.com/ubb/showpage.php?fnum=3&tid=5806 No more board chopping in half, and apparently bye bye to the TLE rail splitter (yay). Now where can I order some SMD 0.1% thin film resistors?....... -Ed

Anyone's got experience with this multimeter? I'm getting into DIY and I have the possibility to acquire a used unit in mint condition for 135$. From what I've read, Fluke dmm are generally a safe bet, but I was wondering if anyone had some feedback to give about this particular model.

I've read a few times that the EnABL process can be applied to Grado headphones, particularly the metal housings ones. I've had my modded SR100 since mid march and I'm wondering if anybody ever tried that on the black or silver vintage SR325 housings or the MS2/HP1000/PS1 and what were the final results ?? I found this paper to be quite interesting : http://www.positive-feedback.com/Issue21/standingwaves.htm Also, I'm gonna buy some Dynamat Extreme for the housings vibrations dampening, anybody knows where are the key places to apply the black tacky-like substance ?! Is there anyone who can enlighten me here ? That would be really appreciated !