Why, there's a buzz in my NAD....

[natlus]

Not exactly a buzz, but more like a wooshing electric sound (herein referred to as the 'sound') that ebbs and flows with my NAD 7240 receiver. I'd like to try to fix it myself, and I'm trying to get the hang of this DIY thing...So some background:

1) I think I've isolated the sound as coming from within the receiver--I ran it through my cans, sans speakers, sans CD player, all unplugged. When a source is plugged in(ie, CD), it does not interfere with the music signal--the music sounds clear.

2) The sound does not change with the volume pot or bass/treble pots or the signal source switch.

3) The sound DOES seem to respond to the speaker switch--if I push or pull it a bit, the sound seems to back off, though it returns. It also changes sometimes when I turn the speaker switch back and forth from A to B, etc..

4) I've used DeOxit power booster and Gold Connector on as much of the speaker switch box and switch behind the face plate, as well as blew out dust, cleaned other pots, etc..Anything I might have missed or a particular connection I need to attend to?

5) I've tried another outlet with same results. The current outlet is used with a Monster Cable AV200 Surge protector. Finally, when I turn the receiver off, the sound builds up and dissipates.

Thanks in advance!

[RoyY51]

Natlus:

As the former owner of two NAD T762 receivers and the present owner of a T763, I can state without reservation that NAD has quality control issues. There has been a laundry list of problems with all these units that has only been rectified by persistance and the willingness to go without, while inspections and repairs have been attempted by authorized facilities. If your unit is beyond the Repair It Yourself stage you might have to travel the same road. However, there is a light at the end of it: you will be rewarded with a beautifully controlled sound at a reasonable price.

Good luck!

[natlus]

Natlus:

If your unit is beyond the Repair It Yourself stage you might have to travel the same road. However, there is a light at the end of it: you will be rewarded with a beautifully controlled sound at a reasonable price.

Good luck!

Thanks for kick starting this thread. It seems that threads in this forum attract many views but few replies--perhaps a reflection of the cautious, plodding approach a DIY'er must take with their equipment?

In any event I am interested in the laundry list of quality control issues if only to create a list of rule outs with my NAD. The units you mentioned I think are the newer ones, while the 7240 is of the 'Power Envelope' series. I've read that poor soldering and something to do with the capacitors is a theme with them.

If you've (or anyone) has taken on some NAD amp/receiver repair, any manuals to recommend? There's one at vintage-electronics.cc but am not aware of its quality.

Thanks again.

[RoyY51]

I just finished typing a lengthy but erudite reply to your question, only to discover that I was no longer logged on, and would have to retype the whole thing. I think that this might have something to do with how long it takes me to type ANYTHING, so rather than repeat this exercise in futility, please allow me to refer you to my review of the T762 on this site. It pretty much sums up what I was trying to convey, but with a lot less wordage.

Again, hope this help!

[natlus]

I just finished typing a lengthy but erudite reply to your question, only to discover that I was no longer logged on, and would have to retype the whole thing. I think that this might have something to do with how long it takes me to type ANYTHING, so rather than repeat this exercise in futility, please allow me to refer you to my review of the T762 on this site. It pretty much sums up what I was trying to convey, but with a lot less wordage.

Again, hope this help!

Couldn't resist. I did read the review--I can feel your pain (ie, visa-vis title) but my sense is that older NADS have different problems than your relatively newer one. Your sound really just fell apart. I've gotten some good tips in these forums on soldering, so it looks like I'm going to get some practice, if I can just get motivated.