Do It Yourself

So for various reasons that i won't exactly go into, i'm about to have a bunch of surplus stuff looking for an application. A bunch of programmed test sources signal generators. computer controllable. All phase coherent to the master reference source. http://www.programmedtest.com/pts500.html 3 x 1 mhz to 500 mhz generators 1 x 1 mhz to 620 mhz generator with dual outputs that can be inter-modulated 3 x 1 mhz to 300 mhz generators one with dual outputs that can be inter-modulated And some CW capable class A RF power amps 2 x 200mhz to 500mhz 50 watts 3 x 10mhz to 200mhz 300 watts As i said, looking for an application. So i contacted craig who is on…

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…

Hi guys,here is my hybrid e-stat amp design using only ONE cascoded voltage gain stage and a solidstate buffer which translate the high output impedance of the voltage gain stage into low impedance. The cascode voltage gain stage uses an ECC88 as input tube, for its low noise and high transconductance, and a 6SN7GTA/GTB to bear the high voltage(anode voltage is around 350V to get reasonable voltage swing). This stage will get approximately 200x, or 46dB gain. And please note that, the grids of ECC88 is biased at around -420V, so you can't really go DC-coupled, coupling capacitors or transformers have to be used. As most digital source components today have an ou…

Well, Pars once said that finding connectors it the (one of the) most boring part of DIY. Well, I can only say that finding a suitable multi-conductor cable might be a very close second. Here's what I'm looking for: total diameter 0.195" - 0.265" 6 conductor 400V will be the maximum potential carried, so I suppose 200V jacket is fine. I'm not sure the maximum conductor diameter, as I cannot find this stated specifically for the Switchcraft EN3 series Here's the "datasheet", perhaps someone else can find it. Switchcraft The funny thing is that they give 14awg ratings here: http://www.alliedelec.com/Images/Products/Datasheets/BM/SWITCHCRAFT/SWITCHCR…

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…

Hello all!! This is my first post here and was hoping that you DIY'ers can help out a noobie. This will be my first attempt at making a headphone cable and would like to know if this is the way to go about it... Unbalanced cable using a 1/4" TRS plug and 2 mini 4-pin XLR's for the headphone end, left and right. Is this the correct way for wire hookup? See diagram below....

I'm building a pair of the rev2 dynahi boards and a pair of Sigma22's and I wanted everyone's opinion on weather or not boutique capacitors make a difference in those boards. Since there's no electrolytics in the signal path (correct me if I'm wrong) I'm not so sure they would make a difference. And I think I remember somewhere that the boutique capacitors often have a negative effect when placed in those positions. My other option would be just to use Panasonic FC's

So as to stop spamming the stax thread, and get everything in one place. I recently got a ripping great deal on an SRA-3S in unknown condition. And since all of these are at least 50 years old, there is much to go through. There are some existing resources to link, and I will come back and add more as i scrape 'em together: It's a shame there are no component designations on the boards or schematic, so we'll go ahead and muddle through without them. Maybe I'll annotate some images. The area in the red box is the phono preamp. It's not much of a preamp. I hear you can pull the board and leave it out. An enterprising nerd could b…

So over the past two weekends I re-cased my original Dynahi. It's always had a slight 60 Hz hum from the transformer (my best guess). The amp boards, psu and tranny are all in one 16" x 12" x 4" case from par-metal. This time I put the transformer in it's own aluminum project box with a cover and then put that in the case. Then I put an aluminum barrier plate that runs the length of the case in between the amp boards and the power side. I used unshield twisted pair wire to hookup the input and output of the amp. The hum is still there as it was before without any of that. My guess is that aluminum project box is not a good shield and I should use shielded twi…

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 …

Hi all, I'm wanting to try building a cost effective ss amp but with opamps I can change out. Something with a small footprint. Is there any sort of Diy in the range of say $200?? THX

So I was out doing errands yesterday and came across a garage sale with lots and lots of electronic stuff. Highly unusual. The guy's wife had recently passed away and he was getting rid of all of his collection over the years. Suffice it to say i bought one standard corvette's trunk worth of stuff, and will go back and get more today. Anyway he had these capacitors i had to have. He said they were for a top secret military project in the very early 1960's. There are no labels on the things, or they came off years ago. He said they were 1000 uf/5000 v caps. So i brought one into work and sure enough it really is almost exactly 1000 uf. He said they were teflon fil…

Hi All... Anyone up for a group buy of IXCP10M90S ? This place below seems to have 146 of them and is in Florida. I know I need them for a bunch of projects and could wait but I'm thinking this might be good for everyone. Has anyone ordered from this place before? https://store.nacsemi.com/Products/Detail?part=IXCP10M90S&stock=XSJMZ0000019254&Mfr=IXYS&auth=n&utm_campaign=listing&utm_source=findchips&utm_medium=aggregator&utm_content=textlink&instock=y I'll run it like my others in the past. I'd say 7-10 people is all we need. I'm in for 30

I have had my beloved ATH-L3000 for many years now. It has developed a frayed cable around the split: I am seeking advice as to possible next steps. Right now, it is not causing any performance issue (has not broken connection). As a safety measure, I have wrapped the entire junction with some blue painters tape to hold it all in place - not ideal. Questions: Is a replacement original cable (NOS) available? - checked with AT - they had no real response - said send it in.. Try to repair the junction? - not much room to work and secure. Is a compatible replacement available (equal quality)? Possible third party cable replaceme…

Well, I'm looking at finalizing a project board that is currently 6.17" x 7.3". The 6.17" needs to be the width of the case, and the 7.3" needs to be the depth. I've looked at a few vendors, as I'm trying to find a width that will accommodate a few of the Hammond 1455 type cases. The Hammond unfortunately is too shallow. I looked at Context Engineering and notice they have one that supports a 6" card width, that might be able to work, with a 8.5" standard depth. I poked around a bit at Teko as well. Anyways, I know a few of you have gone through this and was wondering if you might have a few suggestions? The main deal is I need to finalize the size of the board…

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 …

well the stax mafia has been fairly busy the last few days. So a person over there was asking about a specific amplifier that they thought was WAY overpriced, and significantly under performing. Helped out by the fact that a certain moderator over there was shilling the hell out of it and doing his typical hatchet job on various posts etc. Well that's enough to get us involved. Combined with a picture of high enough resolution posted on the 6 moons website. Guys, seriously talk about giving away the farm. Well... http://gilmore.chem.northwestern.edu/alostudio6.pdf What a massive piece of crap this is. If you really want to build one, its trivially e…

I was looking around for something to bling my tubes around the base on the casework and found a nice and cheap way to do it for those little amps like the Starving student and CTH, EHHA and others with wee tubes. Looking around in Lowes hardware stores I found these solid brass Brainerd door viewers: If you unscrew the ends you end up with a pair of brass surrounds. One end fits the CTH and Ehha size tubes and the other fits the Starving student tubes so you'll need to buy two viewers to get a matching pair @ $7 or so each. When added to the case, you get this nice bling surround. They are pretty deep as you can see so you may need to trim them down depe…

I'd appreciate some advice here. My mini-dacs' xlr output volume is too high for comfortable listening. I intend to make use of attenuators/voltage dividers of type U (shown below) to manage the volume to a comfortable level. That I've seen here I've done some testing and the value of resistance that works best for me is an attenuation of 30dB (68K ohm on both pin 2 and 3 (the R1 positions)). The value of resistance I measure between pin 2 and 3 on my mini-dac when it's unpowered is 4450 ohm. I am presuming this is the source impedance and should be matched by the shunt resistance (shown as R2). My 4-channel rockhopper beta22 is fitted with two dact CT2 atten…

I think that I'd like to get some flux to make things like tinning wires (in a solder pot) and soldering to connectors, etc. more easy. So could you please answer the following questions: 1. Do you use flux? 2. If so, in what form factor? Paste? Pen? Other? Thanks for putting up with my total DIY ignorance and for helping me out.

i just found out there's a lot of similarities between this expensive amp and my 32 dollar headamp kits i built recently my question is: who copy who or it's just a Coincident ?

Hey, I was thinking about using the 220 taps on the primary side here in the US in order to half the voltage on the secondary side of a transformer. Can anyone think of any reason not to do this?

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…

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.

Hi new to the forum and I am interested in building a kgsshv or kgsshv carbon. I have done other projects from amb.org built a beta22 / lcdduino / volume control system. I am unaware if there are any guides or published places to get information on where to start these builds / parts lists? I have found the circuit board gerber files and I am guessing I have to send those to get my pcbs manufactured? But I am a bit confused as there are many versions and variations of build files. For example I see Kgsshvcarbon v1-6 and along eith them left / right / servo / ground. Any advice would be appreciated.