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

I have finished two stage CSG-ACLF-001 AC power filter for audio. I can send one for free to person which has audio experience and can test and write review. This filter decigned for DAC or Headphone AMP or other audio product with total power 150W. Voltage Rating 110-230V AC Dimensions W/L/H 30/60/27mm Earth leakage curent 0.8A Temperature Rating -25C +85C

So I've been on vacation for the last few days and decided to go play with my tube amp since I had nothing better to do. After reading a whole bunch of stuff on the diyaudio forums I got a bunch of stuff together and played around with various power supplies for the heaters in my tubes. First off was a generic DC power supply I got as a kit in the local electronics store way back when. It sounds decent, with Grados there's more background hiss than I'd like but other than that I didn't notice anything wrong with it until I got the good stuff. Next was a benchtop power supply I found in the surplus shop. This is the quietest power supply, with Grados there's just the…

OK, so I did something stupid and accidentally shorted the secondaries of an Avel Lindberg Y23 transformer for two seconds. The voltage seems fine after I corrected the error. Do you think it survived, and or what's the harm in using it?

Im interested in finding out as much about acoustic tubes and pipes as possible and so will be posting key and relevant information right here. I would appreciate any contributions around: -Who were the early manufacturers of piped sound translation apperatus, when did they first come out? -Models names and pictures? -Does anyone own a pair of headphones that make use of an acoustic tube, and are they any good?- whats your call on the worth of the tube?, will it go on... Cheers -Louis

So it looks like the old B&W speakers are ok, which leaves pretty much only the amp as the culprit. Specifically, it seems like one channel is problematic. The sound it puts out sounds very very muffled, distorted, and scratchy. I opened up the amp and didn't see anything that to my untrained eye appears to be obviously kablooey. However, I did note that one of the fuses on the board looks different than the others. It's not blown but could that be it? Anyone see anything else?

My DAC has only one dual RCA output. I would like to use it with both of my speakers and headphones amp (but not at the same time), and don't want to disconnect and reconnect the RCA cables. If I add another dual RCA output by connecting them parallel to the existing RCA output. Would it be any problem?

I managed to pick up a pair of vintage RS-1 (wooden box, brown leather headband, no serial number). However there's no sound out coming out of the right driver. I'm able to unscrew the 1/4 plug and the wires seem okay. Looking into the grill, again the wires seem fine. I'll check the wires against ground with a multimeter when I get home. However, in case worse comes to worse, is there a knack to getting access to the drivers? I've read about sharp screwdrivers, hot water and hair dryer and even spoons ( http://www.headwize.com/projects/showfile.php?file=grado_prj.htm ) though it seems to have been done mostly on plastic or metal-bodied Grados and not wooden o…

I wanted to re-terminate an HD650 cable to 4pin XLR. What is the best way to strip off the black sleeve without cutting one of the tiny wires? I was trying to carefully clip it with small wire cutters but I keep snipping one of the little wires. I also tried a wire stripper and that was worse. Will it make much difference if one of the wires is not connected (as long as the majority are)? Also, I see that the HD650 cable doesn't have shielding so I assume one doesn't anything to the 5th metal connector.

I do not remember I ever started a topic but I am here for a decade or more. I am playing with google AI for a time and I like it. I left out chatgpt so this is new for me. I liked to think I am good to search info from the internet but this thing is so much better. Specifications, go not go situations with some equipment so much easier to resolve. I was curious I asked to design a opa548 virtual ground circuit for me ( this is why diy) and I built it. Not so complicated circuit, I built it and almost worked. The problem maybe was the messy breadboard not the AI, a pin had to be grounded to stabilize the opa. I was a software developer, supporter all my time so I know thi…

AKM post a pic, but still no details...

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

So I sent my K1000 to Fitz a little while back for a re-cable. Today upon removing the wire mesh grills Fitz discovered someone's handiwork... Nice huh? The person I bought them from mentioned that they had new drivers installed, but forgot to mention the custom port in the side of one driver! He also never mentioned they were installed by anyone other than AKG. I've looked back through PMs here and there to discover who the seller was, but sadly can't find the PMs. I also can't find the sale ad. I do remember he was a young kid from England, and it would have been around November of 2008 when I purchased them. Not that I'd get any satisfaction monetarily, b…

Well its done K701 recabled with Mogami 2534 Neglex Copper Quad Mic Cable. Nate had a supply of it, along with the black 3/16" Nylon Multifilament techflex, so I asked him if he could strip the jacket and shield off the Mogami, and feed it through the techflex, which he graciously did Here are some pics (some not so good) of the job: Stock cable Mogami laid into the K701 frame Preparing the 4-pin XLR end of the cable A happy ending On the other ear phone there are two small wires which I have not replaced, but I may leave them for now.

Could anyone who has succesfully built an issue free AlienDAC post your BOM? I will be placing my parts order through mouser or digikey on Friday and want to make sure I get it all in one fell swoop. I spent some time reading the long thread over at HF and it seems like to many people tried something different and it didn't work out. This will only be the second audio gizmo I've built (1st was a CMOY) so any other comments or advice would be appreciated.

Anyone here have experience with one of these? Price is right, but likely too good to be true? https://volumio.org/product/allo-stepped-attenuator/

Have any of you that have the IM716, or took advantage of the Buy dot com deal, removed the volume pod and added resistors? The other site has a thread on this but thought I check here as well. I just got in a pair and also have a few resistors hanging around; although, all I have are 75 ohm jobbies from KSC-35 mod craziness. Other than getting rid of the somewhat sizeable pod holding the switch and volume pot, anyone find it worth the effort?

and about time... I’ve been keenly anticipating this . Here’s a link for those that are interested or have missed the news; http://www.amb.org/forum/gamma3-high-resolution-dac-development-t2656.html

"There is no innovation in stereo amp design in a sense that there isn't any room for it, its based on an hi quality op amp chip that takes and input signal and outputs an amplified signal, the basic formula is still the same in every amp the difference is the ratio of resistors and caps and inductors used (value ratio which influences RC and LC constants in the cir), quality of components and the op amp chip" That is a quote from a local friend. We were discussing the Eico HF-81. He basically doesn't understand how an amp with bad measurements could sound good. Basically, what is truly important in the sound of an amp? I'm not into this side of the hobby but I'm s…

I am looking for a nice metal enclosure for a summer tube amp project. The requirements: Size: Approx 12 X 12 X 3. This is a bit flexible, and it can be oddlong as well. Material: Metal Color: I would prefer black Cost: I'd like to keep it about $50-$75. more toward the low end, though.

MachMat VCCS filament supply Gary Pimm CCS Design by HF member Roam, traced out by me while I was over at his place to pick up transformers for my own project. Yes I have his permission to post it. I spent about 20-30 minutes listening to it out of his Capitole CDP and my RS1, this amp is good, stupid good, but also stupid expensive thanks to the transformers and Emission Labs AD1 tubes. He says he has what should be a slightly purer version in the works using WE 205E's on the front end, but it may sacrifice a bit of bandwidth. No PSU schematic yet as he's still waiting for some parts to come in so it's running off an adjustable benchtop PSU. Can also be built with…

I purchased this DAC from another HC'er in Canada down to the states but it looks like maybe he didn't get around to testing it out before selling it to me as it locks onto digital signals but provides no useful output otherwise. I only have a glimpse of the history of this thing but it's lived a rough life. I am positive old forum favorite NoNoNoNoNoNo is the previous previous owner and the work here is very very bad. Lots of WTF and cold solder joints everywhere and bonus scorch marks on some box caps, that odd white wire is a jumper used after he lifted a pcb trace... As a novice I have since cleaned this thing up as far as I can get it, at least at my skil…

with that video of a home made tube going round these days... (and it turns out that guy was someone i worked with back in the midwest hifi days 30 years ago) I figured i would show a picture of a tube i made by hand in 1976 (at zenith) Has a couple of bugs in it. (actually a bug and a butterfly) http://gilmore.chem.northwestern.edu/tube1.jpg http://gilmore.chem.northwestern.edu/tube2.jpg Proving without a doubt that i was nuttier, longer than just about anyone. (made from picture tube necks)

been working on this one a while, with all the popular transistors disappearing, I hope that this one won't go obsolete before the boards are out. I don't think so because Fairchild has said that the bc parts should be available for at least 5 years but onsemi said the same thing. This one is a diamond transistor input set, used as a voltage to current converter. A pair of Wilson current mirrors with input and output cascade as the VAS and a triple darlington output stage. http://gilmore.chem.northwestern.edu/cfa2.pdf if someone knows of better surface mount parts to replace the bc series, I might as well do that from the start. ft >150mhz, hfe &g…

so this has been kicking around for a while, decided to publish. take my ubaltobal converter, cut it in half, and then take the top piece, replace the input transistor with a tube... high impedance input... DC coupled, no negative feedback, less than .01% thd, 10db gain... just add a high power bipolar output buffer, and cheap tube hybrid with lots of plankton. work in progress http://gilmore.chem.northwestern.edu/tubehybrid.pdf 100 volt power supply real simple with TI TL783 high voltage regulator +/-30 supplies with lm317/lm337 with boosters cheap!