Preamp or Not

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.

I forgot to mention that the other day I was hearing a buzz or spit intermitantly on the left speaker and was worried that a tube was going bad or worse one of the amps! After investigating all my connections etc. I found one interconnect was laying directly against a power cord (perpendicularly by the way). This power cord was feeding the preamp and I'll be damned, that was it. Repositioning the interconnect fixed it. When the noise is occuring try taking a wire and touching to both the amp and preamp to see if the noise worsens or lowers. Do you have a friend with a different preamp that you could see if this goes away?

Espoverload
Sorry I just reread that you have tried new amps etc. Forgive me for being dense. If you know some one with a power conditioner that may be an easy test. Also several years ago I noticed my lights in my house dimming at erratic intervals. This kept happening and it worried me so I had the electric company take a look at my power. On the outside of your house is a a meter. It is fed on three legs. Each leg must read equal voltage. Mine did not. Upon investigation the power company tech said one of the leads was loose at the box in the back yard. This box fed 2 or 3 houses. It is sounding like you have a power problem in your house. Some fluke meters (voltmeters) have ocilliscope screens so you can take a sample of the power at your outlet and see if there is some large scale noise in your ac supply. Good luck!

Espoverload, A cheater plug is a plug with the old fashion 2 blade connector with the big round ground blade removed. You plug your 3 blade PC into it then you plug it into you outlet.

While it is always nice to have one in the drawer to use if you think you might have a ground loop, or where it is, I doubt that is your problem based on the sound you are describing.

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.