Just received this preamp and there is a very noticeable hum at low volume in all modes. If I turn it up loud enough to drown out the hum it sounds great hooked to a nad 2100 amp. Had a Kenwood C-2 preamp prior to this without issue. Any ideas? I tried different connections, cables, settings without positive results.
Nad 1600 Hum
- Thread starter spdracer
- Start date
slimecity
Super Member
I'd be looking at some ground loop basics for this. There are stickies and posts on this site that may assist.
Does the preamp have a 2 or 3 pin plug. Does your other equipment (connected to the same outlets) have 2 or 3 pin plugs? Sometimes where there are a lot of one type, and only one of the other type, you can get ground loop problems.
Does the preamp have a 2 or 3 pin plug. Does your other equipment (connected to the same outlets) have 2 or 3 pin plugs? Sometimes where there are a lot of one type, and only one of the other type, you can get ground loop problems.
NAD80
Super Member
Hello spdracer, AudiOhm. Welcome to AK. I think the power cord is a 2 pin. The Owners and Service Manuals are here on HiFiEngine.com. https://www.hifiengine.com/manual_library/nad/1600.shtml . Just register and download for free.
That was my first thought when I heard the hum, until I realised that it's just humming on the right side. Also, the hum just about disappears after an hour of listening. Everything is 2 plug (old)
Thanks. I have looked at both the manual and service manual
NAD80
Super Member
I have a 3140 integrated amp. Needs recapped. Sometimes just flipping the AC plug around helps on the hum issue. Also check to see if there are any loose ground points (chassis screws) to the case. Check all the caps to see if they look good. NAD cut costs on the quality of the caps on some models.
Never thought of the ground screws, will check them in the morning. All the caps look good to my eyes, but I'm no expert. One prong is bigger than the other on the plug so won't be able to flip it around.
slimecity
Super Member
Yea second the capacitor views on this. Old caps dry out - you wont see this. As they do this they lose their ability to filter undesirable voltages which can get thru and affect the sound.
The fact that you only have it in one channel seems to rule out powersupply issues (as the problem would then be common to both sides). Looks like you may have a full recap on your hands - which probably should be done anyway to maintain the unit.
The fact that you only have it in one channel seems to rule out powersupply issues (as the problem would then be common to both sides). Looks like you may have a full recap on your hands - which probably should be done anyway to maintain the unit.
woodj
Super Member
Only after the problem is resolved.
Are you saying it could be something else beside needing a recap?
Any idea what else it could be?
Binkman
Lunatic Member
IMO reading thousands of post of which if you gloogle nad audiokarma will give you enough reading material for a year.
Caps are notoriously bad... Also "today" somebody posted on finding a Proton P-1100 sm and Nad came up, too. go figure.. leesonic and other builders get a decent return for fully checked out and stable units. if diy? don't chase rabbits and check any nad unit out at the board level.
bink
Caps are notoriously bad... Also "today" somebody posted on finding a Proton P-1100 sm and Nad came up, too. go figure.. leesonic and other builders get a decent return for fully checked out and stable units. if diy? don't chase rabbits and check any nad unit out at the board level.
bink
