Preamp or Not

There are electrical reasons which make a preamp the better choice for most amps out there. I will try to elaborate some other time. However for your cable question, it is worth trying xlrs to see what is going on. It sounds more likely, however, that your preamp is either introducing or amplifying a noise that is already there (rather than the noise being picked up by your cables.) Maybe try the preamp with other amps to see if it makes a difference. If the amp has gain control drop it and see if that helps. It is of course possible that if you are running very long rcas they pick up noise but that would have to be fairly long cable runs...

I have tried passive before and it does sound clear but thin in most cases. XLR was developed to reduce noise in very long runs of cables for bands. It works very well ask any band member of any clout if they use RCA and they will chuckle. I have a BAT VK51SE preamp and I have to say it is VERY quiet! The RCA cable was originally designed for tone arm connections (short lengths). I have had single ended cables and XLR both and I must say balanced is DEAD Silent. You can see my system and see that I am VERY serious about the sound. You can turn on the system and turn the volume to max without the cd playing of course and barley hear audible hiss from JM LAB Utopia tweeter at about two inches to my ear.

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

Espoverload, I briefly revisited your earlier thread in which I participated. Mihalis sort of mirrors my thoughts here. I though you had solved your noise problem when you used some XLR connectors on your amps? Not so?

One thing that might be helpful would be if you could more specifically describe the 'noise' or 'distortion' that you are hearing, i.e. is it a buzz in the lower frequencies which you clearly hear when you put your ear near(er) the mid range or bass, or a higher frequency constant hiss heard more clearly with your ear near the tweeter. You use the word 'distortion' and that covers way too wide a range of possibility of sounds.

Another thing to consider is I/C and PC dressing. PC's and transformers too close to I/C or other components can cause problems. As (IF) you follow my recommendation include an examination of their condition and their placement so you will know if it is the source of the noise.

If I had your problem this is exactly what I would do. Disconnect everything from your amps (except speakers of course). Disconnect these components PC's from outlets.

Then carefully reassemble, one component at a time and identify exactly when this noise appears. For example, when you connect your preamp first connect it to the amp but don't plug it. Listen. Any noise? No? OK then plug it in. Any noise? Yes? Pull the PC from the wall of conditioner and add a 'cheater plug'. Still have noise. OK disconnect PC and remove 'cheater plug'. Noise goes away - OK you now have identified your problem as a ground loop caused by your pre-amp. If the noise doesn't go away consider that you may beed dealing with the pre-amp(s) noise floor. They all have one - whether you hear it or not depends on speaker efficiency, amp sensitivity and gain issues. Pre-amps with high gain and speakers with high efficiency for example will regularly have noise issues which will be aggravated by speaker input sensitivity. I'm assuming the noise if the result of the pre-amp for this drill, but if you should continue the drill thru the addition of source components to see if any differences occur as they are added.

If after this drill you can't find a source, consider that the problem may be riding on your houses wiring and or other domestic items on the same circuits as your audio stuff.

It will be very helpful to anyone trying to help you if you can present a thorough, detailed, description of exactly what you have, what you have done, and the results of each transaction.

BTW your first drill will be in breaking this long winded exercise down into some easy to absorb pieces. :-)

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.