Do It Yourself

I was hunting around in the garage last night and came across an old t-amp I put together many moons ago and it has a TKD pot attached, I bought it quite a while ago and don't recall where from. Are these any good? It's 50k so I figured it'd probably be ok for either the SS I'm about to start or maybe even the Dyna. I can't find too much info on it and nobody mentions them. looks the same as this which is listed as a Ko-on. Anyone familiar with these?

To all the owners of a transistor amplifier V3.0 from http://www.high-amp.de out there in the world. Here is a support how to update your amplifier to the version 4.0 that will be coming out soon. The items below are refered to the following schematic: http://high-amp.de/html/transistor_v3_schematics.html - replace the four resistors R07x and R08x with 51K/1W resistors to increase the current in the second stage to 4mA - replace the two resistors R11x with 200 ohm resistors to increase the current in the last stage to 15mA - replace the resistors R56, R57 by a constant voltage source as shown below (one per chanel) - If you are using the 2SC5466 in the last stage r…

I thought it would be fun to document the insane amount of work it will take to turn the Single Power ES-2 into something useful. Now Kevin had done quite a bit of work for me such as fitted new teflon tube sockets and teflon Stax sockets but that still leaves a lot of shit to do. Here is what it looked like when I got it: The wooden front for the amp section was cracked so Kevin threw it out. The weight of just the empty chassis was pushing 24kg so my first decision was to ditch the PSU and do it internally. First up do the back panel: Here is the reason why I don't add RCA's to my amps... Now for the front panel. Mikhail had plenty of …

This is the story of a very sick little Firstwatt F5 that needs some TLC. This is hopefully the last chapter in a rather sad story involving our Scottish Lord of Drink. Dough bought it from some scammer on DIYAudio which not only botched every facotr of building the amp but couldn't even be bothered to ship it properly. To fast forward a bit I had expressed my intention to build an F5 here and Doug offered to send me this amp to do with as I pleased. I took this a good chance to tinker with an F5 and help a friend out since this amp will be returned to Scotland in fully working condition later on. Now onto what awaited me in that 13kg box from Scotland. Parts …

Is there a balanced to unbalanced (single ended) board that is recommended? Twisted Pear has two options but they use op amps, and then there's the Broskie Cathode Follower, and Unbalancer Two. Those two use tubes. What else is out there?

After almost ten years of loyal service, my KGST is starting to show signs of malfunction. Since last week I have a loud hum in the left amplifier channel. I replaced the tubes with another pair and readjusted the balance and offset. No hum could be heard and I could enjoy the music undisturbed again. The next day the hum unfortunately returned. Readjust everything and the hum was gone. After switching the amplifier off and on again, the hum returned. I have swapped the filaments, but that didn't solve the problem. I also left the gyro turned off, but that doesn't make any difference either. Hopefully someone has a good tip to try.

Has anyone ever looked at, or used these On Semi parts? Look interesting to me. (Mouser part numbers below): 863-MPSW56RLRAG 863-MPSA56RLRAG 863-MPSW06RLRAG 863-MPSA06RLRAG The "W" devices are rated to 1W @ 25C in free air.

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 have question about how to hold a rubber sealing ring in place when closing two halves of an electronic component. I'm trying to assemble a backup controller for my ebike. I want to match up the good front from one controller with the good back from another. There is a rubber seal to go between them. The problem I'm having is that the seal won't stay in its groove dry. Would it be ok to use something like a bit of Vaseline to hold the ring in place? Maybe something else?

Hello Head-Case I am working on an amp using this transformer in a PP output from a 6h30 tube. I would like to know if anyone has had experience with wiring the secondaries in various series/parallel configurations as indicated on the datasheet for different stepdown ratios to drive different load impedances The schematics & articles I could find which use this transformer for headphone use (the Raven, and a few from Andrea Ciuffoli) dont make mention of using the secondaries this way, where other a few others with sowter & "unknown to me iron" do. I think its something worth exploring, but would like to know ahead of time if its a waste of time.

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.

For those interested in another solid state circuit; http://www.diyaudio.com/forums/pass-labs/248112-pass-stat-headphone-amplifier-concept.html#post3753546

Can anyone recommend a reliable PCB manufacturer in China?

Hi all, First of all let me begin to say i am a beginner wit some detailed instuction and BOM i come pretty far. Just finished my O2 and ready for a new challange. I have a new DAP on the way with balanced output so i thought a Balanced in to out would be a great additition. So i have a few options which i cant decide which one to build. -Krell KSA5 Clone -Audiotechnica AT-HA5000 clone - "The Wire" bal-bal amplifier OR the Dynalo which is pretty hard to research because his website is down. This link for instance http://gilmore.chem.northwestern.edu/boards/ My headphones are Audeze Sine and HD650. So not that much dem…

Hi, I recently bought an L300LE, and unfortunately the mechanical part of the headset is rather poor...particularly the plastic frame and the headband adjustment, the former desitinated to break with use because it was too fragile, the latter simply does not hold the set position due to the weight of the headset...I had to put bluetack on it to lock the two slides in place the aluminum frame of the 700 is much better.. but the cost is insane! simply crazy! has anyone made anything DIY to replace these shoddy parts?

What is it that generates a pop/crackle sound when a stepped attenuator traverses steps ? this is happening with my left channel goldpoint stereo volume attenuator, the matching right attennuator in the same amp is unafflicted by this odd effect. One differance I can see between the two attenuators is that the unaffected one has wires linking to chassis ground (xlr pin1) other wise they seem to be wired the same. left -pop/crackle right - no pop/crackle n.b. the loudness of the pop/crackle generated when traversing steps increases as the attenuator knob is turned further clockwise. While on a step both attenuators perform the same. The actual volum…

Thinking about recalbing my K701s... Any suggestions for a good 4-condutor cable? \ I will be running it balanced. How does Mogami 2534 rate? Thanks Pete

So I don't make mistakes in my latest build I was wondering what is reccomended most. Should I twist the AC power leads on a torroid being used in a DAC? Should I twist the DC power hookup wire that will go from the PSU to the DAC board? I'm assuming I should always twist the signal wires...

Hello, I would like to inquire about "caps in the bias supply" for Stax headphones. Spritzer and others said several times that "caps should not be used after the ballast resistor" (for example here: ) In this quoted case it refers to a cap in parallel after the ballast resistor. In other places the same is said about the cap in series, after the ballast ( What problems does the cap cause exactly, in that position? May I ask an opinion about the attached "blinker" circuit (with a series cap...), of which I read a long time ago; I have used one like this for a long time "without adverse…

Does anybody know where to get knobs for the bottom 2 POTS with the dual concentric turning shafts? ALPS Blue Velvet, Bourns Potentiometer and more......

So, I want to build an L-Pad based headphone adapter so I can connect headphones to the speaker outputs of an amp. This is mainly for S&Gs, but if it works great then I have the added bonus of having my innate and poverty-enhanced cheapness vindicated. I was planning to use this information from Meier to optimize the impedance for my headphones: http://www.meier-audio.homepage.t-online.de/ - click on "tips and tricks" and look under the impedance optimization title. One thing I can't figure out (yes, I'm challenged with these types of calculations) is how many watts the resistors should need to be able to disspate. Let's assume I have an amp that maxes out aro…

Hello, I have a Cavalli CTH amp that I built about 8-9 years ago. During that time I tinkered with it and had to rebuild parts of it once or twice, and then again rewired it and installed a new volume pot. Long story short, I burned out the input ground (IG) connection on the board. I was able to get it to connect to some degree, or so I though, but recently when trying to bring it back to life it came off again. I wanted to ask advice on how I might go about repairing this. The IG seems isolated from rest of the board, so am wondering if I can just install a isolated nylon spacer on the chassis and put a metal screw on it, run IG wire to that. IG currently is connec…

Are the connectors Etymotic uses to attach the cables to the pods of the ER4 custom? I'm thinking of building a cable for them and would hate to splice the original connectors.

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.

Hi Everyone, First of all, I'd like to thank you guys for all of the information you have posted on this site. Without all of this, I would probably be screwed, and not able to find enough information on how to make a Stax amp. I have been wanting a sizable upgrade from my pair of HD 595s and after getting the Fidelio X2s which I wasn't too impressed with, have decided to go all the way and get the STAX SR-407 . I decided that I would also like to take this as a learning exercise and build my own amp. I've built a Millet SS Hybrid before, and know my way around electronics a bit, although probably not at these voltages. I have been doing some research over this past …