On Mon, 21 May 2007 11:57:37 -0700 Ken Restivo <ken@xxxxxxxxxxx> wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > On Mon, May 21, 2007 at 07:45:29PM +0100, Folderol wrote: > > On Mon, 21 May 2007 11:10:46 -0700 > > Ken Restivo <ken@xxxxxxxxxxx> wrote: > > > > > -----BEGIN PGP SIGNED MESSAGE----- > > > Hash: SHA1 > > > > > > The M-Audio Audiophile interface produced just as much noise as the Edirol FA-66 did. However, the amp I borrowed was buzzing even with only a regular (Korg) keyboard plugged in, so the problem may have to do with the amp. > > > > > > I also noticed that this laptop's analog video output produces some nasty warbling/ghosting on my external monitor. Looks like rain falling or fog travelling rapidly, especially with dark screen backgrounds. Dunno if that's an improper X setting, a problem with the monitor, or or maybe this laptop is just generating way too much EMI with the Core 2 Duo's 2.33Ghz clock? I hope that's not the problem-- that is one of the few things I cannot change. > > > > > > I've going to buy a keyboard amp, to isolate that variable at least. Off-topic, perhaps, but any recommendations? Most keyboard players I've seen recently seem to have Roland wedge-style keyboard amps. My local store carries the Peavey's (KB4, etc). > > > > > > Thanks Pieter and others for links about noise mitigation. I'll try those suggestions too once I get the amp situation squared away. > > > > > > - -ken > > > > Have you thought of plugging in nothing except a battery operated > > headphone amplifier? With no external earth loops and a high immunity to > > EMI pickup this could prove very revealing. > > > > It sounds fine with headphones, and also sounds fine going into my at home stereo: quiet and lovely. > > However, my stereo is *not* grounded: it has only a 2-prong plug. Intr'stin' > Likewise, the wall-warts for both the FA-66 and the Audiophile are not grounded. Maybe I should try to find a grounded wall-wart? I would expect that to make any problems worse. > How I wish these things were powered by their USB/Firewire cables! > > - -ken I'm afraid I'm late in on this thread so apologies if I am going over old ground. What happens if you unplug the laptop from its wallwart so that it is running off the battery? How about if it is still plugged into it's wallwart but THAT is unplugged from the wall. (I'm looking for possible radiation from any attached lead here) Does anyone at home have a cheap portable LW/MW radio? If so try tuning it to pickup crap from the laptop/interfaces - see where it is strongest and compare that with other similar digital gadgets - not very scientific but could give some useful clues. -- Will J G _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/mailman/listinfo.cgi/linux-audio-user
