To be clear, you hear these sounds with the pre-amp > amp > speaker (no sources connected, power turned on) BUT not with just amp > speaker (power on)? Does the sound change if you change inputs on the pre amp?
To answer your questions:
1. I do NOT hear any hash with the XLR connections plugged into the power amp (powered on) and plugged into the preamp with the latter switched off.
2. Changing inputs does not make a difference, Tape, CD and LP player all pick up the same amount of hash with preamp switched on.
3. I am pretty certain that the speakers are picking up radio signals (well, sounds like radio because I can hear the worst type of adult contemporary music imaginable!) and not cable signals. All the MORE reason I need to fix this!
It's your pre-amp's xlr outputs. Contact Marsh and see what they say, could be something miss wired internally that is ok when you run single ended. I don't understand your 'jumper' description, I thought newer W-5's had a switch to select xlr or rca inputs. It's a bummer problem since both your W5 and the Marsh are suppose to have improved sound if run balanced. Go back to SE connection in the meantime so you don't go crazy. ;-)
It has been a rather depressing couple of weeks. Let me explain:
- I tried out the Cardas XLR and RCA caps, no luck!
- I took my pre amp to my local hi end store and hooked it via the XLR interconnects I use at home, perfect, no issues, no noise!
- I will take both my amp and pre amp to the store and basically try to recreate conditions at my house, if there is a problem then I am on the right track, if not then there is something very wrong with wiring at my house which could mean an expensive visit from the electrician!
Keeping my fingers crossed!
It seems all my components are totally fine - they worked perfectly at the store with all the cables I use at home in balanced mode, no noise issues what so ever. Not a thing wrong with my electrical socket either, I got a Transparent Labs line tester installed on my outlet and the line was diagnosed as having no problems.
Even the most well read and hardcore stereo guru is stumped by my dilemma! No one seems to have an answer; I am hoping that if I install a new audiophile power socket it might help though chances are slim!
Khalid (I may have to move house!)
You might also consider a power regenerator from PS Audio (like the P600), which converts your home's AC power into DC and then re-generates it as AC with perfect sine waves (or something like that...check out their website for details). From what I've read, no power conditioner (including the expensive highly-touted ones) can clean a signal to the purity of the one that the PS Audio units generate, because (since they are just fancy filters) they still rely on the power being well generated (by your power compnay, I suppose).
I have moved to a new house and NO problems! No noise, all xlr connections work just fine. Still, it would be great if someone could come up with a technical explanation of what happened at my old place.
If someone has the spare time and insight, it would be helpful for others pulling their hair out over this.
This is a classic symptom of interference from an AM radio transmitter. For FM and television (which uses FM for the sound), RF interference won't actually de-modulate the audio from the station.
The most likely cause of what you describe would be a mistake in the design of the ground traces or wiring on either your preamp or power-amp, whereby the RF crawling around on the interconnect shields (which is where it's supposed to be), gets somehow injected into the signal conductors.