> When the NB200 was connected to the mains via its charger a very audible > high-pitched whine would be introduced to the recording. However, by > doing the recording on battery power and the whine disappeared. At the > time I put it down to a badly shielded PSU made do with the workaround.
That's definitely switch-mode power supply noise. > Fast-forward to this weekend when I got it into my head to download > Audacity on my Mac MIni running OS X 10.6.8. I hooked it up to the NAD > PP-3 and ripped a new album only to find that the issue exists with this > hardware set-up too. Your Mac also has a switch-mode PSU (as does most equipment these days). > Obviously the original workaround does not apply since the Mini has no > battery to fall back on, but it got me to thinking: why is this problem > manifesting at all? Surely the output from the PP3 is a digital signal > and therefore immune to electrical interference - or put another way - > where is the whine being introduced into the signal? The noise is getting into the signal prior to the ADC stage - almost certainly at the turntable. *Check* your earth, and use a separate, filtered supply for your analogue stages (turntable + preamp). Vic. -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --------------------------------------------------------------
