Do It Yourself

It happened finally. Something killed the power supply on my apogee ensemble. No scorch marks visible, no fuse i can find, it just doesn't power up anymore. I've emailed apogee, but they stopped supporting these a few years ago. I just don't have thunderbolt on my mac pro, and really don't want to go through all that. So I'm torn between replacing it with another one, finding someone to repair it, or getting a metric halo.

finally. higher signal to noise ratio, more than 110db. takes signals up to 20 volts peak to peak unbalanced, 40v peak to peak balanced. no input attenuator that adds noise for those stupidly high voltage dacs. ( requires 30v power supplies) (volume control in the middle) thd about .005% no feedback. work in progress 4 layer board. preamp2025f.PDF

One of these rare amps stopped by for a visit: This one belongs to Stuart but I'm taking a look at it for him to sort out the unbelievably noisy CT2 stepper and do something about the very high gain. I was thinking about a simple voltage divider on the input instead of messing with the circuit. I might also change out the PSU caps as some do appear to be stock. Any further ideas about this beast? I did read Doug's thread on the SHA-1 but I doubt I'll do something as extreme. It very noisy though and quite frankly, doesn't sound very good with RS-2's and Mullard E88CC tubes. Very edgy and with crappy bass. There also appears to be a small channel imbalanc…

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?

Has anyone used a Khozmo Attenuator? They look extremely well built. I wonder how it sounds compared to a goldpoint or a dact

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…

So, I'm working on a pair of monoblocks. swt61 has seen these monster heat sinks. 12.2" wide x 12" tall with 2.925" fins and 0.326" base, weight is 13 pounds... and I got four. I've done some thermal plots of 6 devices per heatsink on a small PCB. Each device is dissipating 14.8W x 6 devices x 4 channels ~ 350W. I'm wondering how much further I can push the devices. The sim data is very close to actual temperatures and since I don't want to drill holes under the devices for thermal probes, the simulator will be gospel. I don't really want to move the devices apart anymore, as I have a PCB in mind I'd like to accommodate, plus a design of my own. Datasheets for devices:…

I was chatting to justin and cetoole last night, asking for a solution to produce low volumes of sound, max -40dB down into the -80`s and below. Comfortably loud for me with my rs-1`s is up to -52dBu with pro mastered (+4dBu) material, using my donuts (yh-100`s) comfortably loud rises up to -44 dBu. The suggestion that came up, apart from a vinyl source was to I know very little about what is required to drive electrostatics so will really need a builder to construct this for me. A pre-built stuffed Stax bias supply PCB is available from spritzer. I`d really like to try this with my SR-3`s. Anyone willing to construct this for me please let me know. I ha…

I'm looking for some new hex keys/allen wrenches. I have the typical cheap set and assorted ones that came with furniture, but those suck because they tend to corrode or get stripped by tight screws. I need a set that is well-made and has more torque than the typical L-shaped keys. I know Klein makes sets, but they can get pricey. Any recommendations?

For fun and experience (and because the KSC75 cable is too short), I would like to recable the KSC75 in my Frankenstein HD580/KSC75. I've seen Mogami and Canare minis recommended. I was looking at Mogami W2799 and W2893 since people claim Mogami is more flexible than Canare. Is one of these better than the other for flexibility? Anything else I should consider.

so yesterday this showed up quoting alex... "In a nutshell, the Liquid Carbon is a fully-discrete, fully-balanced, transportable solid-state headphone amplifier that is capable of driving all but the most demanding of headphones - delivering satisfying levels and offering superb driver control for exceptional detail and linearity." lets run that thru fact check for a second. yep... "Liar Liar Pants on Fire" fully balanced? nope, not in the way that any truly differential amplifier would be. (like any of the super symmetry variants) and absolutely no common mode rejection. fully-disc…

Hi all, I've been more and more interested in building my own amp after having built a relatively simple Elekit amp. I've been reading through the KGSSHV and KGSSHV Carbon build threads and I think I've found the google drives for the schematics and various documents, but it's still a bit confusing where to begin, and I'm not entirely sure I should jump right into trying to build a KGSSHV Carbon. I'm also unclear where one sources the PCBs for any of those builds - seems like various members hold extras and there are some floating around on eBay of dubious origin. Anyway, I'm not exactly certain what build would be good to start out with, or what the differences are …

I have several OPA627 and OPA637 in 8 pin dip. Some I ordered from digikey, some from ebay that could've been digikey samples and some from ebay that aren't. The problem is I acquired some when there were some fakes going around. I didn't separate one order from another and put them all together. I'm sure some are real and some are fake but is there a definitive way to tell?

I've been lending a hand with board layouts for a few projects, notably for a build of Kevin Gilmore's DynaFET design, and doing so made me realize two things: (a) there aren't any DIY projects for amps with a truly high-end feature set, and ( I want one, but I can't really afford it. The DIY crowd has some amazing analog designers and has produced some really astounding designs, but the supporting and surrounding circuitry often isn't much more than a pot and maybe a selector switch, and sometimes a power LED or relay control circuit. There's so much more that could be done to make amps more convenient, self-monitoring, and just plain nifty. So I decided that this was an…

As Luvdunhill has a limit of 100 total for his mini-GB, and the the count was well above 100 not counting myself and luvdunhill, I've got a quote from Trendsetter at 5USD/ea, at minimum of 100, I've decided to organize a GB for those who still wants the LSK389B at 5USD/each, state your interest here At this point in time there are almost 100. Please be aware that the GB started as for SOIC-8 package alone. I have added the TO-71 to the spreadsheet. 20160120: GROUP BUY CLOSED

Nectar Sound, purveyor of the Pollinator and now the Hive headphones, has a DIY amp published on the website. I reached out and picked up a PCB so I can build this low cost energizer and see how it stacks up against my SRM-252S. Attached is the schematic, BOM, image of a completed amp, and hook-up guide. You can also access everything on the Nectar Sound website. Sajeev has updated the board slightly from the images attached to hold a pair of CL-90 inrush limiters to prevent blowing a fuse on start-up. I'm in the process of gathering the parts now, but wanted to post this to archive the build and see if anyone else was building (or has built) one. Nectar1p0_Headp…

topping dx5ii schematic class B output stage. and they seem to be proud of this crap. discuss dx5ii.PDF

I was impressed to see the great work done on these two sets of Stax Lambda Pro drives by Jazz over at Head Fi that I thought that his post should be duplicated here for members to see. Don't know how many times I played with my Lambda phones on my head to see if I could simulate Sigma style sound. Kudos to Jazz for two jobs well done. See JaZZ's custom made Stax Phones here...Homemade Headphones? - Head-Fi: Covering Headphones, Earphones and Portable Audio Jazz's comments below..... The idea of making my own housings for Stax drivers was born out of my experience with the Lambda and the Sigma Pro. Whereas the Lambda sounded too shrill (with the SRM-1 [?]) -- and …

I've seen posts here and there commenting on the difficulty of recabling the K1000, and it's definitely not something a novice DIYer should attempt, but I think most of the fear and confusion over recabling them comes from their unusual construction and lack of information regarding safe disassembly. I hope this guide will help clear up the process for advanced DIYers who are already comfortable recabling normal headphones, but wary about working on the K1000. A few notes before I begin... You should have your cable already built and ready to go before starting disassembly, so the K1000 is not left in a partially disassembled state, and complete the work on one ears…

This amp (plus the matching tuner and a Sony reel to teel) has been sitting at my parents house for as long as I can remember, completely untouched. I was finally curious enough to open it up recently and it is really something special in a vintage kind of way, a germanium SS amp with output transformers. I'm not sure how old this is but late 60's would be a good guess. Now it is about the same size as the larger Stax amps so no powerhouse but I'm a bit interested in hearing it. So here is what it looks like on the inside: Here is the back panel, DIN connectors everywhere plus the output transistors: It is a pretty neat layout and the assembly is bri…

I've been thinking about upgrading to a better soldering station. I am just a hobbyst so the tool is mostly for DIY work. I started out wanting to limit my budget to $200 US. As always the case, once I started reading stuff on the web, I am more and more tempted by those that are way over my budget. Right now, I am looking seriously at: 1. A JBC CD-1BD for around $400 2. A Hakko FX951-66 for around $260 I would love to hear your experience, experience and recommendations. Thanks!

I recently bought a Stax SRM-T1W and in speaking with others online, have heard that the PSU caps might be "dried up" and it's recommended that they be changed by default. Reportedly, the unit sounds/functions fine and is in "like new" shape cosmetically, but I'd like to do the most basic of these changes if I end up keeping the unit as a nearly two decade old bit of electronics is still a nearly two decades old bit of electronics, no matter how it might look. So I'm considering this project my (re)introduction to Stax and so am intrigued/excited about working through a few minor mods, mostly in regards to extending longevity. Can anyone here recommend the PSU cap…

Hi guys and gals, I bought a gamma2 and I'd like to plug in to the wall and use the trasit to send it data across toslink to avoid ground loop issues. Does anyone have any recommendations as to what to buy for a 5v 300mA supply to use with it. Sorry for the dumb question but I'm having no luck finding one and I'm obviously looking in the wrong place.

I'm looking to build something along the lines of the Stax SRD-7/ Woo Wee but with better iron in a lower turn ratio (maybe 1:10/1:15/1:20). Does anyone have recomendations for iron? Spritzer, do you offer your bias boards still? I'll keep my eye out for s SRD-7 with pro connection but in the mean time this could be a fun project. Thanks!

I did search but I couldn't find a dedicated thread about DIY electrostatics so in the spirit of getting the discussion started, here is something I've been working on. Well over a decade ago I bought up all the spare Sennheiser HE60 parts to assemble new headphones. The first thing to go out of stock was the main housing so to assemble the last pair, I had to adept a HD650 housing to take the HE60 drivers. Ever since then it has stuck in my head to make my own drivers for those housings and well... here is version 2.0: I bought a ratty old HD650 and completely stripped it apart. Headpad, earpads and cable went into the trash while the rest went for a l…