Millercarbon's Mega Moab Mod Meander
One of the more useful resources in all my research is this site where caps are compared like fine wine- http://www.humblehomemadehifi.com/Cap.html The top Duelund caps are superb, but would cost more than the Moab - and take up about as much space! So I opted for Jantzen Alumen Z as they come very close for a fraction of the price. Then with a Duelund bypass cap they get even closer. It is one thing to read and look at these things on paper. It is quite another to actually hold in hand. The instant this happens it is quite apparent the Jantzen ring like the proverbial bell. Well they do appear to be rolled inside a thin wall aluminum tube. In contrast, the Duelund caps are in some sort of composite looking material that is thicker and quite inert. Even just a little bit of the Herbie’s material killed a lot of the Alumen Z ringing, and by the time I was done with fO.q tape the Jantzen are now pretty thoroughly damped. The Herbie’s material is thicker and so will double as additional isolation, suspending the caps about 1/8" above the mounting board and apart from each other. Another interesting thing that came up, inductors. There is a very generalized or simplified way of seeing electricity as a current that moves through the core of a wire while fine details ride along the outside, the skin effect. This is really silly simplified, leading to my saying to Krissy one day what we know about electricity is like what we knew about fire a million years ago- Don’t touch, fire hot! Millions like that even today. What’s behind the panel? Don’t touch! Still, we can do things even with this crude understanding. Coil a wire around and around, the fields block higher frequencies while the lower ones pass. This coil is an inductor. Inductors filter out high frequencies. There’s things we can do to improve inductors. An iron core improves efficiency. Eric uses one of these for the bass. Sometimes called a sledgehammer inductor, by Peter Gabriel fans, I guess. I wanna be.... A much better and (of course) more costly method is to shape the round wire into a flat ribbon and wrap the ribbon around with very thin insulation. This is better because we are trying to get the high frequency surface fields to interact and mute and this ribbon geometry maximizes these surface interactions. Also costs a lot more to roll into a pure copper wire into a uniformly thin ribbon and wind it all nice and tight and precise. So that is what we got, and I went for Goertz Alpha Core inductors. The gauge was a bit confusing. Normally with wire the gauge is thickness. In this case we want thin. So it was counter-intuitive at first to hear the thicker gauge is preferred. But gauge is really about cross-sectional thickness. The "thicker" 12AWG is actually ribbon rolled out very thin. But by making it wider we get the extra cross-sectional current carrying capacity. Now it makes sense! Alas, inductors get no love. If there is an inductor website where enthusiasts gush over their favorite inductors ineffable ability to convey the emotion in Tony Levin’s bass line, the perfect combination of slam and fundamental fullness, I have yet to find it. Still, that is what we are looking for here. Inductors also roll off the high frequencies from the midrange drivers. In doing so they affect not only the upper band of the midrange but the lower band of the tweeter. Nobody really seems to talk about this, yet it has to be. So in addition to what seems an obvious bass improvement it seems inevitable that quality inductors also contribute to improved midrange and treble. |
DHL has my Townshend Pods, to be delivered Monday. Crossover components are now ready to be fixed to the board and soldered together. Then stuffed in there somehow. 😳 So girls, my Saturday dance card is full! 😂 The crossover is mounted on an old Omega e-Mat. Thank you, Krissy and Frank for that one. Frank gave me the speaker idea quite some time ago, it has been brewing in there ever since. Mats however are too flexible to support this much weight. So they will be laminated to a BDR Shelf. Before laminating the completed crossover will be set up on Pods in order to determine where they will go. The BDR will then be drilled and tapped with studs used to screw Pods to Shelf. This will allow me to install the completed crossover and use it on the Shelf, and attach the Pods later without having to remove, drill and tap. I have an idea for a quick-release way to hold them in place that will also reinforce the brace. That's the plan. Iron Mike has a great quote about plans. So we will solder it, stuff it, and listen to it Saturday and Sunday. Then Monday with Pods. Anyways, with an eye out for the left hook! 😂😂😂 |
