Hi guys;

I just acquired a 122x/150x combo to replace the 112/90.3 demo pieces I had. They were connected in conjunction with a NAD AV receiver (T753) and REL subwoofer. I had the NAD's sub out connected to the REL's low level input while the NAP's speaker outputs were used to connect to the REL's hi-level input. I was using the low level for movies and the highlevel for music and it all worked fine.

When connecting the 122x/150x instead of the previous pair I got the loudest hum u can ever imagine. I spent a good time trouble shooting and I localized it to the REL. I disconnected the REL's low level interconnect and that took care of the matter.

I need some advice please. The NAD only outputs the 0.1 channel's audio data to the subwoofer out, even if I specify that no subwoofer is connected within the NAD's OSD menu. Therefore I must use the low level (phono) output from the NAD. How can I enjoy the REL with both music and movies?

quote:

Originally posted by Flame:
while the NAP's speaker outputs were used to connect to the REL's hi-level input.

For this connection - please note http://forums.naim-audio.com/eve/forums/a/tpc/f/3452929996/m/4752905007

The best way to achieve this connection is to connect at the SPEAKER end of your NACA5 speaker cables (minimum 3.5 metres, equal lengths, per side).

Consult the instructions supplied with your subwoofer - the cable used for this connection does not need to be of the same quality or gauge as the main speaker cable, twin electrical flex would be sufficient.

By connecting at the speaker end of the speaker cable you ensure that the load seen by the amplifier is as suitable as possible - being determined by the two lengths of NACA5.

As to the earth hum you are experiencing - as you know, this is a matter which requires an alteration to your wiring before any solution will be safe and this is the priority.

It is quite possible that a "Ground Loop Isolator" fitted inline with the REL AV processor lead or that between the AV processor and your 122x may ameliorate THIS problem but the word MUST in "This Apparatus Must Be Earthed" continues to mean that advice offered for your unsafe system does not imply approval of leaving matters as they are.


In addition - you should ask your dealer to contact either Naim UK or the area distributor - to seek advice from our technical department. He will, of course, need to mention the absence of earth connection as this is likely to be relevant to problem solving.

Must_Be_Earthed.jpg (13 Kb, 6 downloads)

That's it Adam!!! I'm gonna get somebody to earth my main socket! Your perseverance (nagging lol) has paid off...

Connection to the REL via hi-level is made at the speaker end of the NACA5. Lastly, the new amps are so great and sounding sweeter by the minute Will probably post my impressions after a couple of weeks of run in.