Capacitor log Mundorf Silver in Oil
I am building outboard x-overs using the Northcreek inductors on the woofers and low mid, and Solen Heptalitz inductors on everything else (it is a 6-way design with 10 inductors, 9 capacitors, 5 resistors and three adjustment pots per speaker). Needless to say if I went Duelund for caps and inductors I'd be broke, so I'm using Mundorf Supreme caps and the above-mentioned inductors!! I might spring for some Duelund resistors, however. I did the driver induction experiment just to see how close I could get to the inductors before I heard interference - it was very surprising how much of a magnetic field they set up. If you put those inductors inside a speaker enclosure you'd better make sure they are far from the drivers. Also, inductors will interfere with each other (look up "inductor crosstalk"). The inductors need to be well separated in space if they are in the same plane (i.e. both lying flat), I found that the bigger inductors need ~8 inches between them in that sort of arrangement. If you place them with their axes at 90 degrees, you can get them closer - see the chart I linked below: http://techtalk.parts-express.com/showthread.php?p=1500176 Iron has a much higher magnetic permeability than air, and that causes the magnetic field of iron-core inductors to be contained in a much smaller space, so they can be placed closer together than air cores without interfering. Iron cores, however suffer from hysteresis distortion and can saturate at high power levels. I have not heard the Northcreeks in a finished speaker yet, only on the crossover prototype board with a driver wired into them - they sound good, but I won't know any more until I finish putting the speakers back together. |
Ait Sorry I was kind of joking with the Iron core. Meaning it is a side benefit of hysteresis. I totaly understand where you are coming from on the cost factor and think you have made good choices. Mundorf Supreme's are a very good bang for the buck cap. I would love Duelund inductors but that is the tough part knowing if that is the best place to put fixed amount of $. Duelund resitors are supposed to be best bang for the buck part as well. Keep us posted on your rebuild. I did check on a seperate issue on the net they had copper prices the lowest in history in 2002. (U.S. $) The second lowest year was 1932. (inflation adjusted price) So today's copper price is not out of line at all! In fact when my speaker were built copper was twice as expensive as today. Steen did say good inductors would be measured in pounds or kilo's of copper or silver etc. |
Sorry copper link. http://www.fwallstreet.com/blog/183.htm Rumour has it that the Chinese want copper (and other commodities) instead of $. So unlikely we are going to see copper prices of 6 years ago maybe the lowest in history. In the 1800's copper was $16 a pound. Those North Creek inductors have 10 lbs of copper in the 8 guage so up to $160 in 1800's copper prices per inductor! http://silverstockreport.com/email/copper_discovery.html |
Sorry guys for the commodity post. The stock and commodity trader coming out in me. I do not own copper futures but other commodities. I bought the first 20 ft of Duelund copper wire. (more to come) Ait like you I am trying for bang for buck. I think that is why threads like this can help. I am getting North Creek knowing (or at least I believe Irish65) that Duelund sounds better but at $1k an inductor! I can get North Creek and V-Cap teflon an amp for less! Now would a VCap'ed amp and North Creek inductors sound better? Not sure but would expect so. Duelund I do have the upmost confidence in your products no doubt but why do your inductors cost sooooo much more than anyone else? Your caps are not? Yes they are more but not that much more. |
