Okay, in the past I sort of made fun of myself about ordering fairly expensive machined caps to cover unused RCA and XLR jacks on my Max and my CD players. The ones I bought are made by Cardas (the only ones widely marketed to audionuts like me), and they didn't provide any sonic benefits that I could hear when I installed them on my Max, covering two unused RCA jacks and one unused Neutrik XLR/headphone jack; as well as on my CD player to cover one unused RCA coaxial output jack (before I started using any outboard DACs). I wasn't bothered by the lack of sonic benefits when I first tried them, as I bought them primarily to keep dust and fingerprints, skin oils, etc. from getting my my unused, unprotected RCA jacks (and to keep dust out of the big, unused Neutrik XLR/headphone jack).
Not too long ago, I received my PreHead from Meier Audio, and it has twelve total RCA jacks on the back. I'm only using two inputs (so four total jacks), leaving eight unprotected jacks (nine if you include the unused Neutrik XLR/headphone jack on the front panel). Naturally, I ordered a bunch more caps to protect the eight unused RCA jacks and one XLR/headphone jack. Did they make a sonic difference this time? Believe it or not, this time, yes. I didn't try putting them on and taking them off when music was playing, but I did try the following: setting PreHead gain on high, CD player playing zero-bit track (total silence) through Bel Canto DAC2, and turning the volume on the PreHead all the way up through Grado HP-1 headphones. With no caps on, the very mild background noise with the volume all the way up has a slight rasp to it. With the caps on, most of the rasp goes away. I've done this a few times now, and the results are the same. The eight RCA caps seem responsible for most (if not all) the difference, because when I remove and replace the XLR Cap alone, I can hear no difference; removing and replacing the RCA Caps does illustrate the difference.
What're they blocking out? I'm not sure. Does this have any impact on sonic performance when music is playing? Maybe in some miniscule way, but I haven't really gone out of my way yet to see -- I just received all the new caps I needed to cover up my naked PreHead today. Though not a mindblowing thing, I was admittedly surprised to find any difference at all. Why do they present a difference for me with the PreHead, but not the Max? I'm guessing it's based solely on the quantity of RCA jacks -- again, my PreHead has eight unused RCA jacks and one unused XLR/headphone jack; and my Max has only two unused RCA jacks, and one unused XLR/headphone jack. Some time next year, I'll probably be buying some new home theater components (most of which have dozens upon dozens of jacks nowadays) -- when that time comes, I'll have to order a bunch more of these things to see what kind of impact it has on such jack-laden components.
NOTE: These are non-shorting caps.
Here's a photo (an old photo I took for a past review) of my Max with a Cardas XLR Cap covering the unused XLR/headphone jack (this will not work on standard headphone jacks) -- I am using one just like this to cover the unused XLR/headphone jack on my PreHead:
Here's a photo of the back of my PreHead with the Cardas RCA Caps covering eight unused RCA jacks:
Not too long ago, I received my PreHead from Meier Audio, and it has twelve total RCA jacks on the back. I'm only using two inputs (so four total jacks), leaving eight unprotected jacks (nine if you include the unused Neutrik XLR/headphone jack on the front panel). Naturally, I ordered a bunch more caps to protect the eight unused RCA jacks and one XLR/headphone jack. Did they make a sonic difference this time? Believe it or not, this time, yes. I didn't try putting them on and taking them off when music was playing, but I did try the following: setting PreHead gain on high, CD player playing zero-bit track (total silence) through Bel Canto DAC2, and turning the volume on the PreHead all the way up through Grado HP-1 headphones. With no caps on, the very mild background noise with the volume all the way up has a slight rasp to it. With the caps on, most of the rasp goes away. I've done this a few times now, and the results are the same. The eight RCA caps seem responsible for most (if not all) the difference, because when I remove and replace the XLR Cap alone, I can hear no difference; removing and replacing the RCA Caps does illustrate the difference.
What're they blocking out? I'm not sure. Does this have any impact on sonic performance when music is playing? Maybe in some miniscule way, but I haven't really gone out of my way yet to see -- I just received all the new caps I needed to cover up my naked PreHead today. Though not a mindblowing thing, I was admittedly surprised to find any difference at all. Why do they present a difference for me with the PreHead, but not the Max? I'm guessing it's based solely on the quantity of RCA jacks -- again, my PreHead has eight unused RCA jacks and one unused XLR/headphone jack; and my Max has only two unused RCA jacks, and one unused XLR/headphone jack. Some time next year, I'll probably be buying some new home theater components (most of which have dozens upon dozens of jacks nowadays) -- when that time comes, I'll have to order a bunch more of these things to see what kind of impact it has on such jack-laden components.
NOTE: These are non-shorting caps.
Here's a photo (an old photo I took for a past review) of my Max with a Cardas XLR Cap covering the unused XLR/headphone jack (this will not work on standard headphone jacks) -- I am using one just like this to cover the unused XLR/headphone jack on my PreHead:
Here's a photo of the back of my PreHead with the Cardas RCA Caps covering eight unused RCA jacks:
Who knows, but if they protect them, AND make a small amount of sonic change, they might just be worth looking into. It would probably break the bank to buy enough to cover all the RCA jacks on my Melos amp!!!
