I received my used NAP-300DRr/NAP-300PS today but on connecting it all up I’ve got hum through both speakers when at zero volume on the preamp which doesn’t change when rotating the volume knob.
I’m on the upgrade path having owned the NAP102/napsc/hicap/NAP180 for 24 faultless years. I know it’s not exactly conventional to swap the 180 for a 300 but a pre-amp upgrade will happen in coming months.
I have the. burndys connected from PS to amp with the green markers at the amp end. The din to xlr are connected with the red on the right channel. Green on the left. These are connected to output 2/3 of the hi-cap (as per the original connection guide of how to connect 102/hicap/135s. The XLR to din cables are brand new, unused by previous owner. Swapping the dins around in sockets 2/3 makes no difference
The hum doesn’t go away when the hicap and napsc (and CDX and ND5XS2) are turned off.
I don’t suspect the ‘new’ amp in any way, but struggling to find a resolution.
Is there a preferred order for rack placement ? Full system is CDX, ND5XS2, 102, napsc, hicap, Nap300dr/ps into Shahinian speakers
Are the burndys sensitive to ground lops/hum ? With ONLY the nap300 powered up but other components still connected I still get the hum.
The amount of cables doesn’t make for easy routing
I am not familiar with your equipment and I do not wish to tell you how to suck eggs and insult your intelligence. For me I would go back to basics and ensure all NAIM equipment is fed from the one power board from one power outlet. I do not know which country you are from. I am from AUS and we have 240V mains which allows for thinner copper conductors that can carry 10 amps for the same 2,400 watt power output from a power board and a single power outlet. Your case may differ if your mains is 110V, larger conductors and possibly less sockets on your power board.
Please let me know more. I have not checked your bio and will do so now.
If you have never had your units serviced, then proceed with caution.
If the NAPs are new to you, did you audition?
Otherwise, don’t assume any of the interconnects are in perfect order.
Cable dressing will be key, as is stack order. Is this all on a Fraim?
Post a photo and someone with similar units may be able to offer suggestions from their experience.
I agree that it’s now a process of elimination. No change in mains cables used, not even changed the plugs around on the musicworks 6 way power block
I’m hoping ive either got a wrong connection or too many cables/power supplies close to each other
Just to add I’ve not tried to play a source yet due to the hum, sources are fed to pre-amp on Naim hiline interconnects, as previously with the 180 in place
Not on a Fraim It’s on a 6 level wooden rack made by a company called Project (not the turntable people). Bought 20 years ago and the company don’t exist any longer. It’s not the rack itself, but component placement could be key.
Siting the 300dr and 300ps on neighbouring shelves above each other does mean the Burndys are sort of half coiled/looped in the available space
If it’s an earthing issue it would normally get louder as you increase the volume. That it doesn’t makes me suspect it’s a Burndy problem. Can you try putting the two parts of the 300 on the floor side by side and then connecting them to the Hicap? You may need to put the whole system on the floor side by side to be able to do this.
With it turned off, try removing the burndies and then reconnecting, to make sure they are engaged properly. You may want to try this first, before dismantling everything.
My first (late night) inclination would to first try your preferred source top, then NAC, then NAP head unit, then 2nd source, then the small units and then NAP PS.
Variations on that should improve cable dressing. Check you have all i/cs correctly orientated.
Thanks for the replies and suggestions. Got to go to the office for the next couple of days but some checks and potentially reordering seems to be the next steps
I had a similar experience but on one channel only, when I switched to the SL interconnects. Took quite a scare, finally solved by fiddling with the socket, pulling out the XLR connector a little bit, most likely the ground connection wasn’t done properly. Try on your side as well.
Disconnected and reconnected the two Burndys this morning. Connectors were locked home at both ends, so no surprise that on removal and reconnection there is no change in the ground loop.
I have a new suspicion though !!
I have one non-Naim cable in the system - a Russ Andrews Kimber 5 pin DIN 240’ to 5 pin DIN 240’. I ran this previously from the Hi-Cap to the NAC-102 pre-amp for power only, there was no signal path through the Hi-Cap to power amp. RA offer two versions with this plug configuration, power only or power+signal. Email to RA this morning, replied to within 30 minutes, has confirmed that the cable is power only (4 wires, 2 to negative pin, and two to positive pin).
So i’m hoping that replacement with suitable SNAIC will resolve the electrical path - only issue is that my SNAIC cable is 140 miles away in another system.
Edit - Naim SNAIC now ordered, black version which i believe is the later version and potentially better quality then the earlier grey one