buzshaws
Active Member
Member Kahoona did a nice thread on his .2's that he restored. At the end of that thread I had a question about his crossover circuit and how it differed from the Infinity schematic, which is the same my v.2 crossover circuit is based on. I have seen several crossovers like Kahoona's, probably more than the layout in the schematic, which is really interesting but also begs a question as to the reason for the changes. Here's Kahoona's thread, with a link at the end to the PDF schematic:
http://audiokarma.org/forums/index.php?threads/infinitesimal-nudies-and-question.546437/
After I made a post in that thread about the crossover differences, it seemed it would be better served in its own thread so I started this one so the topics remained independent. I'm revisiting this issue because I'm still at an impasse as to what's going on. My Infinitesimal II crossovers were modded when I received them. Film caps had been replaced with a Mundorf Supreme and the resistors changed from the original sand cast units to Eagle resistors. Lytic caps were replaced with Bennics. Not crazy about the choices I decided to get Deulund graphite resistors and Mundorf MCaps to replace the "replaced" ones still and waiting to install them until I get another 5-way binding post. Original owner did that already too but I'm not crazy about the ones he'd chosen. If the original stock components are going to be upgraded in any way then I prefer to put in the ones of my choice.
Now back to my original quandary. Kahoona's crossover is different than my initial pair, which correspond with the widely available schematic linked to in the above post. Unlike Kahoona's version, it illustrates two 5 watt 1.4 ohm resistors and a .2mH coil in the tweeter circuit, but Kahoona has two 2.7 ohm resistors @ 5 watts and no coil. I'm sure his was all original and stock when he did his restoration/upgrade. This is reinforced because I just got a "new" pair of Infinitesimal II's and this pair's crossovers are just like Kahoona's version. Everything is stock and they came in the clear poly bags inside the box. They could almost pass as NOS and likely never opened up until now (the enclosure that is). Truly remarkable but that's another story. The reason I bought them is I wanted a pure stock pair that had been untampered with so I could have a reference to experience and therefore understand what an original pair is supposed to sounded, then any changes or upgrading of components has a baseline for relevence. I'm perplexed at the differences in the two production crossovers and the Infinity schematic being the only document available regarding the v.02. Those are pretty significant differences and surely will affect the sound. If Infinity made such a revision, and clearly they did by evidence of the schematic and my two v.02 samples, which is the most recent? I'm of the opinion the resistor value changes to 1.4ohm and added the HF coil came later, as it would only be implemented if thought beneficial, as it indeed increases the cost. A manufacturer doesn't do that just for fun, especially when such a change is inside a box that no one sees. I don't plan on changing my recent ones in any way because they are perfect and sonically represent what an original pair were when new, but my other previous pair is based on the schematic and I have the components to upgrade them already, so they're free to put the modern components in. Any feedback is just for enlightenment because others that may want to change electrolytics and the film caps, as many want to do, may wish to take note that what they see in their crossovers indeed differ from the said schematic and there will be a choice whether to change similar for similar or base the choices on the schematic. I can't help but think if one wants to follow the schematic that in addition to adding the .2mH coil, the resistor value change should be considered part of that revision too.
http://audiokarma.org/forums/index.php?threads/infinitesimal-nudies-and-question.546437/
After I made a post in that thread about the crossover differences, it seemed it would be better served in its own thread so I started this one so the topics remained independent. I'm revisiting this issue because I'm still at an impasse as to what's going on. My Infinitesimal II crossovers were modded when I received them. Film caps had been replaced with a Mundorf Supreme and the resistors changed from the original sand cast units to Eagle resistors. Lytic caps were replaced with Bennics. Not crazy about the choices I decided to get Deulund graphite resistors and Mundorf MCaps to replace the "replaced" ones still and waiting to install them until I get another 5-way binding post. Original owner did that already too but I'm not crazy about the ones he'd chosen. If the original stock components are going to be upgraded in any way then I prefer to put in the ones of my choice.
Now back to my original quandary. Kahoona's crossover is different than my initial pair, which correspond with the widely available schematic linked to in the above post. Unlike Kahoona's version, it illustrates two 5 watt 1.4 ohm resistors and a .2mH coil in the tweeter circuit, but Kahoona has two 2.7 ohm resistors @ 5 watts and no coil. I'm sure his was all original and stock when he did his restoration/upgrade. This is reinforced because I just got a "new" pair of Infinitesimal II's and this pair's crossovers are just like Kahoona's version. Everything is stock and they came in the clear poly bags inside the box. They could almost pass as NOS and likely never opened up until now (the enclosure that is). Truly remarkable but that's another story. The reason I bought them is I wanted a pure stock pair that had been untampered with so I could have a reference to experience and therefore understand what an original pair is supposed to sounded, then any changes or upgrading of components has a baseline for relevence. I'm perplexed at the differences in the two production crossovers and the Infinity schematic being the only document available regarding the v.02. Those are pretty significant differences and surely will affect the sound. If Infinity made such a revision, and clearly they did by evidence of the schematic and my two v.02 samples, which is the most recent? I'm of the opinion the resistor value changes to 1.4ohm and added the HF coil came later, as it would only be implemented if thought beneficial, as it indeed increases the cost. A manufacturer doesn't do that just for fun, especially when such a change is inside a box that no one sees. I don't plan on changing my recent ones in any way because they are perfect and sonically represent what an original pair were when new, but my other previous pair is based on the schematic and I have the components to upgrade them already, so they're free to put the modern components in. Any feedback is just for enlightenment because others that may want to change electrolytics and the film caps, as many want to do, may wish to take note that what they see in their crossovers indeed differ from the said schematic and there will be a choice whether to change similar for similar or base the choices on the schematic. I can't help but think if one wants to follow the schematic that in addition to adding the .2mH coil, the resistor value change should be considered part of that revision too.
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