Do It Yourself

I just bought a 1lb reel of Kester 245 solder online and the date of manufacture is 11/30/04. The website says that their leaded solder 'goes off' after 3 years. Given this is almost 6 years old, should I return it or not worry about it and just use it? Slightly reluctant to return it as Kester is not so easy to get locally here in the UK and I wanted to buy a decent/premium product for my first forays into serious (non-disastrous) soldering.

I was going to name it 'Double the Carbon, double the voltage, double the fun', but I'm afraid that would be too wordy. Ever since I measured the output swing capability of the Carbon, I wanted to see if it can drive my ESL speakers. To do that, I'd need a beefed-up version that can output at least 1kVrms before clipping. That's 1414V peak, out of a ±750V to ±800V PSU. To simply scale up the Carbon amp and the GRHV PSU without major changes to the PCBs, a few hurdles would have to be overcome. First is the 900-V rated 10M90s in the cascode CCS that bottom out with ±450V PSU. When I was browsing the high voltage FETs at Mouser, I found the UnitedSiC UF3N170400B. …

Does anybody have a source? All I see so far is chassis mount.

I've never done this before, but partly due to seeing a pic of an amp that Nate had built, I was thinking of countersinking two screws on the bottom of the l'espressivo torpedo prototype that I am building for my brother. So, a couple of questions: [*]Is a Hammond 1455 case such as what is used thick enough to countersink a 4-40 flat head machine screw in? [*]Countersink bits: do you need one for each size you are doing? I would be most likely to use 4-40 or 6-32. [*]Angle: I see 82

Check it out - it even has pics of the populated board at the end of the PDF, hehe! http://www.eserviceinfo.com/downloadsm/21578/Melos_Melos%20Sha%20Gold.html

planning to build an electrostataic amp for my SRM L700. I have built several amps for my Moving coil earphones (HD650, K601, K702...), but never built an electrostataic one, I read some topics about it, also some diagrams of amps , there are still some questions need your help. 1. Never saw the full differential structure (for example, opa1632, lme49724) used in the electrostataic amp, why? 2. The electrostataic earspeakers have much larger impedance than moving coil ones, the only capacitive impedance is isolated by the output resistor (usually 5.1k), so...the electrostataic amp works like without loads? 3. Why the output resistor is usually 5.1k ? …

For those who haven't been browsing HF: This is some amazing work! http://www.mundohi-fi.com/portal/index.php?module=pagesetter&func=viewpub&tid=8&pid=8&page=1

Quick question and likely an easy one, but it escapes me. If one were to have a power meter on the front of their amp, say, like the D'Agostino Momentum, what would it be connected to? I assume across the power supply...or would it be across the output? Thanks! Gratuitous picture for fun.

Does anyone know a supplier that sells the square wood tube amp cases with the metal top for mounting the tube & transformers?

With all those new balanced amplifiers around I can't really resist and I want at least to have a taste of that heaven with a balanced 650, so, what is the most beautiful sounding but also simple DIY balanced amplifier in your opinion?

Hi, n00b here. Please dont get out your shovels or hammers, i'm just asking a honest question. I've noticed that the term "sand" has been used a lot in the DIY Forum when referring to semiconductors. Does this mean something along the lines that transistors and diodes are made out of silicon, basically quartz "sand"? Therefore: sand = semiconductor? Since semiconductors are generally not considered "passive" devices, maybe it could be a fancy acronym for Silicon Active Node Device? I've searched high and low and could only find this totally geeked-out reference: Self-Assembled Nanodielectric. Could this explain "sand"? Or is it something else? …

Head-Case DIY'ers, I've got a quick question on wiring for neatness. What is a recommended method for tying two 18awg cables from a transformer into one quick connect terminal? Should it be a short piece of 18awg cable soldered to both at one end, adding heat shrink over the junction? Thanks, bperboy

was trying to re-wire the left driver of my ad700's, when the actual tiny copper solder tab lifted off the base of the driver... I still have it, but how the hell do i put it back??? It is the bottom left solder tab on the left driver (ground). Have i completely screwed my cans or is it fixable. Any advice greatly appreciated!

When I found out that amb had designed a single-rail version of the σ22 power supply I thought it sounded just about perfect for my Squeezebox3 power supply project. Here are the preliminary results. This PS is actually for a friend but mine will be very similar with just tweaked casework. If you want more info on this PS have a look here. I did just a little testing tonight and the new PS definitely seems to have helped the anemic base that the SB3 DAC has with the stock PS. More on that later when I can back to back it with the DAC I'm currently using.

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…

Ok, I have a quick question. So, I have some of these sockets, with brackets: I need to somehow embed a nut into the bracket, so I can then secure them to the top of the chassis. I won't have access to the bottom of the socket. I don't know much about PEM nuts, but I was wondering if something like that might work. I'm leary to try an adhesive, or soldering, etc. but maybe it might work, but I'd prefer a better solution. If someone wants to make me a bracket, that's a different story, but let's assume that's not a viable option either.

A mate at Auriculares posted the link to this article which may be of interest for you DIYers. Not being a DIYer myself I found it interesting nonetheless.

So as most people know, the Qualia 010 Medium-sized headband is actually too big for most people. I have the M-sized headband myself and have been struggling to get a nice fit with it. At first I was using a folded-up linen to close up the space between the headband and the top of my head but it always felt ridiculous (and looked ridiculous too) so the other day I began looking for a better solution and one day while doing some routine cleaning, I realized I could use a sponge! Yes, a sponge, and it ended up being perfect - just the right amount of leverage and comfortable too. There was only one last issue, how to attach the sponge to the headband without causing any dam…

ok, I'm finishing up a Twisted Pear Buffalo DAC using the soon to be released Legato III I/V output stage. I intend to use the BAL/SE stage in the beginning since all of my headphone amps are single ended. However I want to build a balanced headphone amp. It will be the balanced dynahi or M³ and I'm concerned about the statement below from Twisted Pear. What does this mean if I build a balanced M³ or dynahi rev2?

I'm building a Xono clone. I need to match 2SK170 JFETs and BC550 BJTs. I'm new to transistor matching - Google has left me a bit confused with the amount of "suggestions". Any clues as to the best / most convenient method, hopefully with a link to a tutorial?

We have lots of info on good parts, but I can't seem to find good tools. I don't mean multimeters and soldering irons, I mean the guys that do the hard work but go unnoticed, like helping hands and wire strippers. In my experience, the standard helping hands thing from PartsExpress is a little flimsier than I'd like, and I don't know how to determine a good wire stripper since I only have the one from a group buy with not enough sizes. Feel free to throw in whatever cool tools you like too, because what is a man without his tools?

Dunno if anyone here might want to say something in this thread: http://www.head-fi.org/t/707823/intellectual-property-giveaway-on-the-discovery-of-terminal-illness#post_10316570 But I will certainly miss him.

I have a Quattro I and II with different issues, appreciate anybody who has repaired CDP's. I haven't opened these up yet, doing some research first. Quattro I. Has tracking issue. Has trouble tracking some disks randomly (some 20% of the time) Quattro II. Sticking/opening drawer issue. Possible to replace the drawer mechanism? Any replacement drawer pointers? Thanks much -

I built my original Dynahi 8 years ago and I'm going to re-case it to match my other builds and to fix some hum because the transformer is in the same case. I built a stereo version with two one channel boards powered by one PSU. I do not remember how I arrived at the value of the transformer I have now but I think it's 160 VA. The original BOM for the PSU says 250VA. Should I go up to the 250 VA spec'd in the BOM? Or is the 160 VA enough? I was thinking of trying to reduce the size of the transformer because of the hum but now I see I may have undersized it.

Basically a two part question. I want to get some isolation feet for some of my gearses and speakerses. The speakers are easy, as I know they are M6. But... 1) How would I go about determining the thread size where I don't currently have a screw? In other words, the component has a threaded insertion point, but I don't know what size it takes. 2) For those components where I want to replace the current feet, what's the proper way to measure the screw so that I arrive at the proper thread size?