Noise/interference prob after adding power amp

[stilgar1000]

Hi all,this is my first post so many thanks in advance for any replies

setup
laptop playing apple lossless into Beresford tc7520 via airport express connected optically Roksan K2 integrated amp,Roksan K2 power amp,Dali Ikon 6 speakers Chord Chameleon Silver + inters,Chord Oddyssey speaker cable.

I have recently added the power amp making a bi-amp setup and now have a problem with noise/interference.I have the Beresford in pre-amp mode and after about 15 mins of use a very annoying electronic type noise starts,I would describe it as high pitched beeping almost like a slowed down version of the noises an old dial up modem used to make when connecting and would seem to be electronic in nature rather than an electrical hum/buzz.
I have plugged and unplugged everything several times with out curing the noise,yesterday I went back to the original set up of just the Beresford and K2 integrated and the noise has gone so that would seem to prove it`s something to do with the power amp,could it be interfering with the Beresford in some way?
I am starting to wonder if the power amp may be faulty as it`s strange that the noise only starts after 15 mins or so rather than straight away.Any suggestions/advice most gratefully accepted,sorry to be so long winded for my first post but this is driving me nuts!

[Marco]

Hi matey,

Welcome to AOS

Can you do me a favour please and pop into the Welcome area and tell people your first name, basic location and music tastes, as this is the required procedure for all new members.

Cheers!

Marco.

[stilgar1000]

Whoops,not a good start! Will rectify my glaring error immediately

[Alex_UK]

Hi Phil, this will be a laugh, me trying to help... but at least I am trying! (welcome, BTW.)

I agree that it sounds like the power amp is at fault, if going back to your initial configuration remedies the problem. I'm not sure how the K2 integrated works, but assuming there is a pre-out, can I suggest that you set it up using the integrated as a pre, into the K2 Power, with a source directly into the "pre" but not using the Beresford? This will confirm or deny that the power amp in itself has a problem totally unrelated to it's co-existence with the DAC.

Assuming this setup works fine, try the Beresford in line out mode into the K2 Integrated (still as a pre) and see what that gives you.

Not sure I've made any sense, the heat could be getting to me!

[Butuz]

It would be a good idea if you tested the power amp straight out of the beresford variable outputs. See if it noises then. I suspect it will!

If no noise - then try as alex says - getting rid of the beresford and running with just the integrated and power.

Frankly I would dump the integrated anyway (unless you need it's inputs) as Beresford straight into Power amp is a great combo!!

Butuz