Do It Yourself

DACT Type 21 Stepped Attenuator Potentiometer 50K 300B - eBay (item 120473999989 end time May-24-10 11:05:02 PDT) Check these out, they look rather nice, any reason why I should try one out? The Rk27 on my millett is suffering from a much annoying channel inbalance! One of these would fit right in!

Toying with the idea for my Dynamite. Anyone hear the Goldpoint smd design vs the Dact? How about feel? Just put in a 4-ch Alps blue velvet pot, to replace a cheapo I had. I also put in pre-attenuation resistors cause I had the old pot turned to almost off for the levels to be right. Much better.

Im making this for my friend who is deaf in one ear. Its my first time making one of these and i would like to confirm that the wiring would be as follows IL1 IL2 IG IR1 IR2 on the input side then on the output side would be OL1 OR1 OG OL2 OR2? Sorry to ask such a newbie question but i would really like to make this work for him so that he can enjoy good music.

So I am just about to start building an M3. I have several questions and was hoping to clear them up here. If these questions have already been answered feel free to point me to another site/thread. I think M3, M^3 and MMM are too short search terms but I got nada in thread titles. My plan is to build an M3 using the AD8610s, with adjustable gain. I would like to use switch-controlled digital potentiometers for both the gain and the volume, but I haven't finished designing that circuit yet (and I also haven't found a readout LCD w/ microcontroller mini board suitable yet) so in the meantime I am going with an RK27 for volume and a gain of 8. I only have low impeda…

I'm looking to get an inexpensive bench power supply, hopefully for less than $50. Can anybody recommend one. If not, please recommend the least expensive ps that will do the job. Thanks.

I've decided to get serious about learning electronics. Tangent suggests this: The Art of Electronics 2/eby Paul Horowitz and Winfield Hill Cambridge University Press, 1989 1125 pages, hardcover ISBN 0-521-37095-7 Would you agree with this or would you suggest something else? I also plan on getting the Tube Amp text that Birgir recommends. I just need to find it again someplace in the DIY threads. Edit: Would it be "Valve Amplifiers, 4th Ed" by Morgan Jones Birgir? Or maybe "Building Valve Amplifiers" also by Morgan Jones?

Please. Suggestions for a balanced SS amp to power LCD's. B22 seems to be the only one I can find. Thanks!

I'm looking to build a DIY tube amplifier (for low impedance cans) for about $500 (excluding enclosure and tubes) that can match or beat the performance of my PPX3 SLAM 6SN7. Any ideas?

Keeping in mind Kevin Gilmore's design rules i have insomnia about stabilizing common mode of JFET input stage without sacrificing CMRR or straight referencing it to the amplifier/source ground. So, check attached schematic. While keeping straightforward signal flow aka "Gilmore's gesign rule" it also have second control loop which helps SuSy amps to maintain output common mode near ground potential.

could anyone grab a few meters of surgical silk for me? I'd like to use it as a turntable belt... I know there are doctors in the audience

Recently I purchased a B22 from Spritzer. The unit was built by Nate, so it's a nice Nugget Audio 3 boards + 1 Sigma 22, single ended, 8x gain unit, made to work on 230VAC. Apart from exquisite care to avoid hum and lower the noise floor, it features a dual input to select from two sources from a rear switch. Spritzer had changed this feature to a loop, so the switch was disabled and while one of the inputs is used, the other one works as an output. I point this because that switch resulted a handy addition. The amp works very well and sounds great with all of my cans, but as time living with it passed, I started to feel annoyed for the fact that being my so…

Is there a general preference?

Hello DIY guys, I hope you can clue me into good part sources. I want to build a switcher box. I have two sources and three destinations. (My two sources are my CD player and my computer; three destinations are two headphones amps and a speaker amp.) So I want to build a 2-in 3-out switcher. I want to switch ground as well as the signal so that the grounds of my sources do not have to be connected together at all times. A friend of mine is Don North, who is an experienced designer and builder of equipment, and could probably give me all the help I need, but he's a busy guy! I'm going to get info from this forum if I can. Don did give me just a bit of info. He said I co…

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.

I was not really planning on going into work next week, but this has changed my mind. http://gilmore.chem....n.edu/ebony.jpg 1500 grams, 8 x 2.5 x 3.5 inches about 50 years old.

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

Hi all, As part of my home theater build, have decided to go for 3 way actives for front LCR… so, need to build 9 power amps for fronts and 8 amps for surrounds… to pair up with my Sherbourn PT-7020A pre/pro. I needed something as easy, but more powerful. This is when I and my friend John found the datasheet of TDA7293. This IC can run up to 100V, low distortion, and can easily be paralleled. Having built single chip amp and extensive listening TDA7293 is my favorites for IC power amp applications. I have been looking for a source of PCBs using parallel TDA7293s… there are not many out there that you can buy. We then decided to do our own PCB. Our schematic is almost…

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 ...

ujamerstand had his university make up some of my version of the stax jacks, maybe he is willing to sell a few. I have 3 of the 6 pin teflon versions that i make left, i'm not going to make any more jacks this year due to lack of time. You could always plug the center pin with an appropriate teflon rod if you wish. Someone needs to organize a group buy and find someone in china to make a large batch of them, with REAL teflon.

So i just build a crack /w speedball and it all went well and it is sounding great. Except that the stock pot is pretty shit and i wouldn't mind a remote control. After some searching i came across this one: http://www.tentlabs.com/Components/page31/page31.html Some specs: Input impedance: > 40 k-ohm (actual value depends on volume setting) Output impedance: < 8 k-ohm (actual value depends on volume setting) Power: AC or DC, 6 to 10V max, current max 150mA DC, 225mA AC (power connector supplied with module) Volume setting: 64 steps of 1.0 dB Channel imbalance: < 0.15 dB Inputs: 4 Input / Output connectors: Cinch / RCA (can be supplied without conne…

Hello Board Im working on a shitty little amp that assuming the stars and plannets are in alignment will be at canjam. at the moment, not 1 part has been soldered but the casework is done and being painted.... Now that I have cursed my project by admitting that it exists: The case (a cheap "BUD box") that I am painting with hammer-tone paint, because it will (hopefully) mask some of my horrific screwups with the drill and could not ever look even close to as bad as a naked BUD box. I painted one corner of the top a little thicker than the rest, should I worry? Im going back for coat #2 in about 45 min... Thanks Ari

Man, I forgot to add 4 1000uF/50V Panasonic FM capacitors (P12393-ND) to my last Digikey order... anyone happen to have some on hand, or about to place an order and wouldn't mind shoving 4 parts into an envelope and sending them my way?

Hi guys Just finished my Bijou. It's only got about 20 minutes on it so far, but this thing sounds great. I'm currently listening to Fiday Night in SF with my K701 - very sweet. I'm not so great at describing the sound, but this amp certainly delivers - to me at least. Cheers Oh, I've temporarily mounted it on a piece of board so it looks pretty ghetto, so I won't post pics.

This is probably going to seem like a go-to-Head-Fi thread, but I'm in a bit of a DIY and audio equipment rut, and I really trust Head-Case a whole lot more to get me out of it...... I've built myself DACs for home (Buffalo) and office (y2). I've got an M3 at the office with Audio Technica ESW9's and AD900's, I have the Exstata with SR-Lambdas at home, and I've built and sold a couple of Millett Hybrids. I'm pretty chuffed with all of this equipment, but feel that I'm still a long distance from my audio end-game and really want to keep doing more DIY. So where do I go now? I'd really like to challenge myself with something new to further my electronics skills, and keep…

Given the outcry for some documentation on how to build some of these ESP amps I think it is time for a thread on the subject. Now the plan is to post here a summary of the parts needed to build a KGSS amp using the boards from Headamp.com plus what ever build/mods of Stax amps come to mind. KGSS Now for some time people have claimed that the KGSS is somehow hard to build when it really couldn't be further from the truth. My first DIY amp was a KGSS with those horrible old PCB's using offboard heatsinks and caps but after blowing up a couple of boards and PSU's (I really didn't have a clue as to what I was doing) I had two working amps. Now the new boards make …