[proaudio] Hello all! General linux daw question. Problems with x and h/drive events creating interference..

["independent commercial" <independentcommercial@xxxxxxxxx>]

I think this is the first time I've posted here, so thank you all for your advice and especially to the devs who created this overlay. 
I am having problems with my amplifier amplifying noise from what seems to be activity on the PCI busses.
First, a little bit of history.

I've been using this overlay for a little while and apart from underestimating my need for space on my /usr/ partition have had reasonably good luck with the setup. I have an A7m266 asus (AMD northbridge) motherboard with a Barton mobile cpu pin modded to 2Ghz. No problems there, runs well with cpuburn for some time. On the first slot is an LSI scsi card connected to 2 drives which have the root/swap and home partitions mounted on them respectively. Unfortunately no matter how much swapping around and fiddling in the scsi bios even though I am only using one channel and the other channel seems to be disabled, the second channel always takes a good IRQ. So, I've used that channel for the drives and the first, so-called disabled channel shares with the Matrox G550 card which drives a Dell 1920x1200 lcd monitor. Was the best I could do. The card has AGP 4x and FastWrites enabled in xorg. My kernel has the realtime-lsm module enabled and working, no preemtive RT patch. No problems there with xruns. The card is on the third slot and is an M-audio delta 66, it has it's on it's own IRQ of 9. There is nothing in the second slot. I realise if I moved the SCSI card to the second slot then the card wouldn't have to share with the AGP card but then it /always/ shares with the audio card which I figure is worse. Plus the actual SCSi channel sharing with the AGP card has nothing running on it (the drives are the channel which has it's own IRQ). I've read the 
d.robbins article on irqs but will have another look to see if there is anything I missed.

Here is the gripe and really is a strange one and I was hoping someone here might be able to point me to the right direction.
Ok I am getting noise from x and drive events from the (admittedly average quality) amp, but not from my headphone amplifier which is connected to the other 2 channel outs on the card. Is it possible the amp is feeding back into the card through the rca cable to create these noise issues? I've swapped channels from the headphone amp and integrated amp on the audio card and still the same results.

Any ideas, I am sorry if this is not the correct place to post this question.
I would like to add this overlay seems to work extremely well. I did use another daw distro and had less than perfect results with jack and everything working properly.
Kind Regards, Nicholas