What's in a NAIM?

Does the NAIT5i produce the same hum when you connect another source? Does the Pioneer produce the hum when connected to another amp, TV, etc....? Could the television/monitor produce some feedback through the video or audio connections? Are you using multiple audio outputs on the Pioneer? Do you have any kind of "conditioner" or "protector"?

I know this doesn't answer your question, but after 20+ years of doing custom systems, I've had to do my share of trouble shooting with such issues.

You might read the Naim manual to make sure the settings are right. I have designed/installed several Naim systems through the years it seems like there are some settings on the NAIT that allow preferences such as RCA and DIN connections.

Also look at the video settings and connections on the Pioneer. Video outputs can have a lot of audio problems when not setup or hooked up correctly. Don't rule out the fact that there could be a technical issue with the Pioneer and/or video system.

http://www.naimaudio.com/support/manuals

Here is a link to the Naim manual site. I hope it works out for you.

I am using the DVD as my CD transport, since it also plays SACD.

I have tried isolating just the amp and the DVD - still hums

I route the DVD for normal play via optical link via Cambridge Audio DAC - no hum.

But the DVD only plays SACD via the left/right channel audio output and that's when the hum starts.

I measured an AC signal (i.e. the hum) of around 1.5 V AC between the neutral on the interconnect and the ground at the outlet - but I also found this with 3 other DVD players from other manufacturers, so I think this is normal, since it has no effect with other amps I have.

There are other reports on the web of similar problems with NAIM amps, so I am wondering if anyone encountered this before and had a fix for it.

I have also posted a related question here, but it is more a question regarding the design of various sources

http://forum.audiogon.com/cgi-bin/fr.pl?htech&1277418935&openusid&zzWilliewonka&4&&

The sources that hum are the ones where an AC signal can be measured.

I have an old AKAI and a Luxman amp and there is no hum aparant on either of them with these units

I have gone as far as switching all the breakers off except the dedicated line to the amp - it still hums - so I do not think it is from an external source

Lost for things to try...

Seems that the NAIM is very sensitive

Try this...it solved a similar problem for me w/ a Denon universal.

A short run of solid copper wire (bell wire - Home Depot) from the center screw of the electrical wall plate to a CHASSIS screw on the Pioneer should solve your problem.

Good luck.

If the system has coax connected from the cable box or to the TV disconnect it. If it is the cause, you need a ground loop isolator.