eric343

That's an impressively well-built amp.

One forum has already tried this: http://ipastudio.com/forums/ If you take a closer look, you'll find that the forums are barren wastelands of non-discussion. Only the LaRocco forum weighs in with a double-digit thread count, and most forums are still under three threads. (The TTVJ forum on Head-Fi likewise has fewer threads than any open-discussion sub-forum but the Meet Impressions forum, and fewer posts than all but the Music FS/T forum.) I would think that given the potential complexity of managing forums for who knows how many manufacturers, it would be better to create a melting-pot for commercial discussion and then branch-off sub-forums for manufacturers or topics that have traffic levels high enough to warrant it. If any manufacturer or topic ever gets that far, that is! I do like Hirsch's suggestion, not in the least because the props from such an esteemed member make me feel all warm and fuzzy If HeadCase is founded in the spirit of minimal moderation and maximal expression, it makes sense to give not only the hungry and oppressed but also the manufacturers and businessmen a place to talk.

Since Head-Case has of late begun its own DIY cable gallery, I'd like to discuss what I think is appropriate for such a gallery. Given that the Head-Fi DIY cable gallery has been used for commercial promotion by certain members (see the Ruh Roh thread), it would be nice if we could avoid that fate here. For example, posting glamour shots of cables for the purposes of attracting offers to buy is in my opinion not right. The DIY forum exists to help people build components which they could otherwise buy and promote the hobby of doing the same. At the same time, people should be encouraged to go into business if they're interested, since doing so fosters competition and therefore better prices and (hopefully) better sound. (witness the level of sophistication that Cmoy amps on eBay have reached, or the quality of cables coming from the various hobby makers such as ayt999, or any number of other examples) Therefore, I would suggest the following: a) It is not appropriate to simply post images of cables without giving a description of their construction, such that anyone could duplicate those cables given freely-available resources. Leaving out a useful description has the dual effect of discouraging others from duplicating your efforts (thereby decreasing possible competition) and adding nothing to the general body of knowledge regarding DIY cables. Describing the construction and materials allows others to discuss the same, while the simple fact of their listing may encourage fellow DIYers to try construction and materials which they otherwise wouldn't. On the other hand, simply posting glamour shots can only be detrimental in that it encourages people to focus more on the style and outwardly visible construction than on the actual technology. After all, props and encouragement from a glamour shot will be given only based on what can be seen in the shot. Commercial entities should not post pictures of their creations in these threads. While I don't think that this should be enforced too heavily, given that small entities have few other means of advertising, a for-profit manufacturer posting their photos is rather like an NBA player joining a street pick-up game. The pro ought to use their experience to advise and encourage the amateurs rather than simply showing off. I might be a little utopian, of course. Or maybe reading all the Supreme Court cases and judicial philosophy for this class I'm taking is starting to get to me.

I wouldn't call it "truly" ProSink-ed, since it's getting quite far from the idea. A "truly" ProSink-ed cable has a resistor from signal to ground at the sink end of the cable, equal in value to the impedance of the cable, nothing more or less. The in-line source-impedance resistor that Kevin describes may (and probably will) improve performance, but also customizes the cable to that system -- just like my crazy "bracketing" idea. Call it 'ProSink Custom' if you really want a shiny Genuine Marketing Term for it, I guess Regarding connectors-- I'm a big fan of the Cardas SLVR/GSMO and especially the SRCA. The WBT Nextgen have more detail & top end, but the Cardas are more musical & natural. Since the connectors in my experience are the only thing that affects the sound of a ProSink-ed cable, you can really go to town tweaking and comparing here.

You can't measure the characteristic impedance without a TDR. You don't really need to, either. Since you're DIYing, you can either: a) Use 300 ohms for wire that has 300 ohms on the box; or, Be anal and make the cable with 270, 300, 330 ohms, pick the best-sounding one, then bracket +/- 30 ohms to be sure, then bracket +/- 10 ohms, repeat centered on the new value, bracket +/-5 ohms, repeat, bracket +/- 1 ohm, repeat. But you'd have to make 24 cables, or modify the original pair 23 times -- so I'd at least suggest stopping when you can't hear a difference! In all fairness, though, you might not hear a difference at even the first step. The advantage of the bracketing procedure is that you'll find the best value compromise between the termination of your cable and the load on your system, which could be many many ohms off the actual impedance of the cable. You might therefore end up with a cable that sounds even more mindblowingly-awesome than a "proper" ProSink-ed cable, but that sounds awful when you put it on a different rig and/or change your source and/or amp. The idea of bracketing and the idea of the best value for the termination resistor being different than the impedance of the cable have not been tested (by me, anyway). Use at your own risk (of sanity, in any case).

Best thread ever.

Power cords -- well, how much power would a 50 ohm resistor dissipate with 110V across it? Internal hookup wire -- sure, just use small form factor coax.

I suggest that we neither invite nor admit people simply so that we can use them as virtual punching bags, free of normal Head-Fi moderation oversight. Doing so will likely result in this board becoming and remaining the Mos Eisley of headphone boards, while treating people as targets is satisfying but bad for you in the long run. (just like any other vice)

Good idea, and PPL.

The easy way: a) Pick some decent coax. The Risch stuff will work fine. It will probably be 50 or 75 ohm, because it's hard to find anything else. Put a resistor (of value 50 or 75 ohms, cable dependent) from the center pin to ground at the sink (amplifier or whatever) end of the cable. The KG approved way: c) Figure out what the output impedance of your source is. If it's less than 50 or 75 ohms, put a resistor in series (with the center pin) to make it 50 or 75 ohms.[1] Before a): Use a TDR to measure the precise impedance of the cable and make sure that impedance is constant to within the precision of your choice, then pick out 0.1% resistors of the appropriate values for steps and c). [1] If your source has an output impedance >75 ohms, use 300 ohm TV antenna-cable twinline or 450 ohm ham radio nutjob twinline. Decent quality 300 ohm stuff is almost impossible to find, but the beauty of this trick is that you won't hear a difference. Now go out and buy the most expensive connectors you can find, because they do still affect the sound.

The problem I've always had with the HeadWize forum was the crude software: specifically, the decidedly bare-bones search. It's not possible to find, say, all of Apheared's posts, or limit your search to an arbitrary subset of forums. Compare that to the features offered by a modern forum software, like this one or even more so Head-Fi.