Do It Yourself

Interesting read..... http://www.humblehomemadehifi.com/Cap.html

As above. The 2 DACs I have already haa digital volume control which I believe are provided by the AKM/ESS chip. Thanks

Looks like a DIY ESL? Best regards Moray James.

not sure if there is any interest, but ran across these: DODD AUDIO DIY

my GF and I want to build a ferrofluid sculpture. We'll need a pretty damn powerful electromagnet to make it work. The problem is where the hell do we get a powerful but inexpensive electromagnet. I'm hoping that we can build one. Is this something that a total amature can pull off?

I have a 30" Monitor that is awesome, but the Video Controller chip has issues with the Lead Free solder joints going cold and causing Video issues. The fix is for the board to be re-balled with Leaded Solder. Anybody know someone who could do this? Here's pix of the board: It's the Altera chip with the issue

I just bought a 1lb reel of Kester 245 solder online and the date of manufacture is 11/30/04. The website says that their leaded solder 'goes off' after 3 years. Given this is almost 6 years old, should I return it or not worry about it and just use it? Slightly reluctant to return it as Kester is not so easy to get locally here in the UK and I wanted to buy a decent/premium product for my first forays into serious (non-disastrous) soldering.

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 was going to name it 'Double the Carbon, double the voltage, double the fun', but I'm afraid that would be too wordy. Ever since I measured the output swing capability of the Carbon, I wanted to see if it can drive my ESL speakers. To do that, I'd need a beefed-up version that can output at least 1kVrms before clipping. That's 1414V peak, out of a ±750V to ±800V PSU. To simply scale up the Carbon amp and the GRHV PSU without major changes to the PCBs, a few hurdles would have to be overcome. First is the 900-V rated 10M90s in the cascode CCS that bottom out with ±450V PSU. When I was browsing the high voltage FETs at Mouser, I found the UnitedSiC UF3N170400B. …

I have a Nice 20" Craftsman D.P. I bought recently. So I'm drilling (butchering) a computer case presently and the tapered chuck spindle keeps dropping off! I cleaned it up real well and have seated it against a blcok of wood with some pressure. Fell out pretty easy. I retracted the chuck and pounded it in with a dead blow hammer. Didn't help. Then took a small masonry hammer and some wood and pounded the crap out of it I thought. Still fell out. What's the super secret way of wedging that gadget in there!

Not sure if this is the place, but I need knowleadgable people abou the subject so here we go: I study design and I'm thinking about building a hybrid headphone/computer speaker, and was thinking about the difficulties of this. I'm uncertain if it's at all possible, because I'd have to meet the sensitivity and dB output of both a regular speaker and a headphone speaker. And I can't actually design one (I'll only design the prototype around it), so I'd have to use something that's already out there. Sound quality is not really a concern, it just needs to be acceptable. One thing I considered was to have a regular driver (sort of those used in laptops) with some kin…

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!

I've read as much as a I on the topic and there seems to be fair arguments for both amps. It seems HC fosters a fair few with impressions of both amps, so I figured I'd ask here for opinions. My situation is this: I don't plan to begin building/organising the eventual winner of this topic for at least 5 months, but as the changing of hands of djgardner's KG amp stash to AMB has offered me a wonderful oppurtunity. Get the boards and the majority of the transistors from one place, and Ti even offers matching which would cut down on alot of the hassle. All in all, this may be the best opportunity I have to build a dynahi. But I don't want to build it if the β22 would …

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.

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.…

If I take say 1 120 Ohm 5 watt wire wound resistor for each channel that's sufficient for a dummy load correct?

I think I'm moving on from Par-Metal. I can't get them on the phone any more and email response is spoty. Has anyone found a chassis supplier on Ebay that can sell something better? I'm looking for boxes that are 16" wide x 12 - 16" deep by 4" high and where I can have front and rear panels milled by FPE

so due to a comment i made over there, someone wanted to know if i had the eddie current dht filament schematic. here it is. eddiecurrentfilament.PDF

Just wondering if anyones tried Craig's teflon, pressure adjustable tube sockets? They're very $$$ ($70) but if I was building a 300B/2A3 amp using "the good stuff" parts, it wouldn't be totally out of line. http://www.eddiecurrent.com/Tube_Socket.html

Hi, I know there are many schematics like this but this aims to be a very cheap amplifier for the estats and it should be better than the SRD boxes. The power supply for tube has +-300 V and there will be four windings on transformer for heaters. I know I can not trust the simulation so I think it will have a maximum output voltage around 500 V peak to peak with some luck, probably less. I took the CSS from SRX+, so credit goes to JimL. Output current is set to 6mA per one output. So 12mA per channel. I added small feedback to stabilize it with 470k resistors. My goal is to make a small cheap amplifier. Voltage output is rather small than other amps bu…

Hi Gents, I

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 !

Yes, I know I have it backwards, but that's intentional -- and the question. Is there a way to modify the ER4s to give it ER4p capability? Say perhaps by splicing it above the resistor and having two plugs, one of 100 ohms, the other of 27 ohms? Or perhaps by putting a resistor in parallel instead of in series? (Not sure why you would do this, unless you really didn't want to throw away that resistor.) And then it would be what, 37 ohms, right? Yes, I am looking at Fitz' ad.

Saw this stuff for sale on diyaudio and thought of you guys... would this be the proper stuff for making electrostatic headphone membranes? diyAudio Forums - ESL films any interest?

As somewhat of a learning experience, I decided to build a PSU using the kgbhultraminipsV4 board (KGBH). All seemed to go well in assembly, and I tested every adjacent solder point for proper continuity, and ensured no cold solder joints. Used proper heat sinks on the silicon devices wires while soldering to avoid overheating them. Cleaned the board with 99.99 alcohol. I set the board up with 2x100v and 1xs150V zeners to output 350V. I plugged it into a 300V x2 transformer (smartly using a very long extension cord in the garage) it I got a HUGE pop. I was using 5W zeners, and when they go, they really go! It was the Positive side of the PSU. One zener totally evap…