Preamp or Not

Thank you for your suggestions. The major reason I'd like to use XLR connection is distortion. I hear a high frequency noise (distortion) from the mid-range and tweeters of the speakers. When I disconnect the RCA from preamp the noise disapears. I have tried everything and can't get rid of the distortion. The noise is not from the amps only when the RCA from pre is connected. So I was thinking if I could eliminate the preamp and go directly from source to the amp with XLR, I may be able to avoid the distortion. Otherwise, I am OK with the system's sound.

Thank you Newbee, 4est and all others with comments. I guess if preamp was not necessary for sound quality, everyone would use a CDP with volume control. I have a couple of decent preamps but both introduce distortion when connected to the amps. I think my distortion problem started when I sold a pair of very good gold and silver RCA interconnects. I am not sure if I had the noise before and didn't notice it or the cables I am using now are not as good. A passive preamp may do the trick as has been mentioned before, but I don't want to buy a bunch of new equipment and still have the distortion noise. So that's why I am asking members to provide me with their experience. So far I have learned a lot. I would appreciate any info on "ground loop", etc. It may be very obvious to most but I am in the dark when it comes to complex trubleshooting. Keep those great comments coming.

Thank you for great comments.

Mihalis, As far as changing amps and preapms, I have done all that with no positive results. My interconnect runs are less than a foot so the length can't be an issue. Nither of my preamps have external gain control.

Booboobaer, I am glad you confirmed that it is possible to hear no noise from you speakers at maximum output with no source. I was begining to think this is a normal anomaly. I have tried various speakers as well and the noise is still there. since there is no noise from the amp with no connection to the pre. the problem is isolated to the pre unless there are other factors involved. My system sounds very good, at least to my ears, but it's one of those thing that you want to find a reason for and ultimately a solution. The only reason I have not yet decided on a new tubed amp and XLR connection, is that I have no reasonable degree of assurance that after spending another several $K, I will eliminate distortaion. Since I have tried multiple amps, preamps, speakers, power cords, wall socket, etc. without any result, I am in a dilemma to purchase another piece of equipment. So I am hoping one of the members with the same problem can help. All comments are very valuable and I welcome all. Thank You

Newbee, Thanks for the detailed response. I Understood your response to the last thread and that's how I isolated the problem to the preamp. The noise is a high frequency distortion (hiss) only heard in the mid-range and the tweeter at high volume. As I stated in this thread, my pre and source have only SE in/out. So in order to try balanced connection, I have to purchase a new pre and good IC. Again, I am happy with the sound of the system and I don't need to upgrade at this time. However, if that's what it takes to get rid of the noise I'll do it. But different members have different points of view. Some say XLR makes no difference unless you have very long runs and some indicate it makes a big difference. That's why I'd like to try everything else before committing to buy more gear. I'll try your suggestion on disassembling the entire system and tryng to isolate the source of the interference. I do have several PC's, IC's, RGPS transformer in close proximity to each other. Also my amps and preamp are very high gain and speakers are 8 Ohms with 91db sensitivity. I'll try some more thigs as suggested and post the results.

BTW, what is a cheater plug? Thanks for your help.

Thanks both for your comments. A long time ago I had a similar problem with My B&W 803N. I asked my dealer and he said make sure nothing is connected to TV or Cable. I disconnected my CD/DVD from TV and that fixed the problem. The hiss is identical but so far nothing has worked. I am confident the moise is not from any one component since I have at least two of everything and changing amps, preamps, PC, IC, does not help. So I think there is a simple solution but I haven't figured it out yet. I'll keep on trying everything you have suggested and hopefully put this problem behind me and enjoy the music. Thanks all.