Do It Yourself

I got to thinking, that my source outputs PLENTY of voltage, so I could possibly get by with a headphone amp in unity gain, only suppling additional current. Is it possible to properly operate the dynahi this way? I am aware of how to change the gain, and fortunately dgardner socketed the gain resistor for me. My understanding of gain tells me that this resistor would essentially be bypassed to run unity gain, correct? The unusual nature of that setup is what made me wonder if it were possible. Certainly I could stick in a 100ohm resistor to get to a gain of 2, right? At any rate, is there any point to this? I figured that lower gain would equal less noise, since the v…

Well I traded for a pair of ALO jenna cable rewired 701s and of course the left channel is cutting out on me at the earcup. I have a 4 conductor extension that highflyin9 did for me a while back that is totally transparent to me so I thought I would use that cable to rewire these. Ken did a second entry so I am all set up to attempt to wire them balanced but I can't seem to be able to get into the earcup has anyone done these yet. I would stick with the jenna wire but it is all of 5 feet and I need a min of 10ft any help would be appreciated

Hello! I am building a set of DIY headphones in a headphone shell that has a 50mm mount. I could also add an adapter to accommodate a 40mm driver. I am looking for a nice driver for this shell. I tried two different drivers from Aliexpress and neither were very good. Any suggestions?

OK, so I need to replace a resistor on one of my ESL-63s so it matches up with the one Kent repaired. Kent sent me very detailed instructions that I think I'll be able to follow. Basically I have to unsolder a wire, unsolder a resistor, install the new resistor and resolder the wire. The rest is just disassembly that can be done with a screwdriver. My screwdriver skillset is pretty strong so I think I'm OK there. I'm looking for suggestions for a soldering iron. Currently the resistor swap is the only task on my DIY schedule. To be honest I doubt I'll be constructing CMoys anytime soon, but who knows? So I don't need the best iron ever but I want to avoid buying ju…

Gang, My Dad seems to have misplaced the wall wart for his EC/SS. I know it is a 16V AC wall wart, but I'm not sure what exact specs I should be looking for. Any help is appreciated.

I met Per Lundahl at Capital Audio Fest last year, and in trying to figure out what I could use I'd have for Lundahl transformers I asked about winding something that can drive e-stats, planars, low impedance, speakers from separate taps. I had also just bought a bunch of 6336B dual triodes, so thought that might work. The transformers came and many months went by but finally rigged something up. Basically right now it's just 6336B with both triodes in parallel, running about 200mA with a B+ of 260V. There's an e-stat output that steps up, and also 50 ohm and 6 ohm outputs. The grid voltage is set by a bunch of 9V in series. The black box in the middle on top o…

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

We're doing a quick moving T2 board set group buy; there are two members and we have a quote for two more (but will go ahead regardless). Specs are ... FR4Blue solder MaskWhite silkscreen2.36 mm thicknessENIG3 oz cuIPC-class 2100% e-TestedThe buy consists of a set of the full sized boards; one power supply and one amplifier board, $225 for the set + shipping and PayPal fees. Post interest here and we will close the buy in one week. If we have more then 4 participants the price will be lower.

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

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

a couple cool projects have popped up recently, one by Papa himself and one by John Curl's number one fan, Grey: http://www.diyaudio.com/forums/showthread.php?s=&threadid=120673 http://www.diyaudio.com/forums/showthread.php?postid=1484933#post1484933 Just figured someone around here might be interested!

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 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 …

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

Hi Gents, I

I happened to be reading the Head-Fi DIY forum today for the first time in probably a month or more and came across a thread that pointed at Par-Metals site. The short of it is there appears to have been a semi-catestrophic fire at Par-Metals office/warehouse at the end of January which has currently halted all production of enclosures. I checked Antec's site (the one I actually care about) and they are very limited in what they have as of 2/4 but are saying that they'll be restocked in one to two months. Anyway, just figured I'd give folks a heads up. I can work around the delay on for my project so it's no big deal.

Per the drawing below, where's the best place to solder the ground wire?

Has anyone built this balanced beast and tried it out?

Could someone point me to a schematic for re-termination of a Jade with a Stax Pro plug? Thanks, Jim

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…

Do-it-yourself-ers and MOTs: If someone had a mid-fi device that you knew nothing about, what would be your first recommendation? I'm fond of my X-Tone, but suspect it has cheap op-amps and/or caps in there -- any recommendations? I also have a MF X-24K that I suspect could be better. For that matter, I have a whole slew of X-tube stuff -- X-Pre, X-CANv2, X-LP2 -- I suspect the recommended mods for the X-Pre would be the same as the mods on the X-CANv2, neh? If anyone wants me to post pics of internal organs, let me know.

Hi All... I was cleaning up and found a pair of Electraprint OPT that I had wound for headphone impedance. I've attached the values. I got these for a build of tubelab's TSE that has now changed to a TSE II. My plan was to use 45 tubes for the output, that would give me 1-2 watts. The headphones I use are HE-560 and HE-6 SE. I have HD-650 and Beyer DT-770 (250 Ohm) as well. My thinking was to start with the 32 ohm tap and connect them directly to the headphones. I don't want to fry the headphones or blow my ear drum if something goes wrong so I'm looking for a sanity check. Should I build it for headphones and use these OPT's or abandon them and get a new set …

So I want to print a holder for some supercaps. Anybody here disign in 3d regularly?

I normally use FMs in most cases, but I see that they have come out with the FR series which are supposedly lower ESR, higher ripple current and longer life? Anyone use these, or are FM good enough? Or other? Use for now would be in PSU filtering for an I/V stage.