I have a NAD 7400 PE stereo receiver (late 80's/early 90's) and I've recently noticed that the left side is weak, with significantly less volume and bass (switching the balance between the two sides). This happens with both speaker settings (A and B - different sets of speakers), and regardless of source (CD/video/tuner). I switched the speaker connections to make sure it is not a speaker problem - it is not. It also happens through the headphone jack. Not sure how long this has been happening. Does anyone know of a likely cause? I'm guessing it's a capacitor, relay or transistor somewhere in the path but I'm just wondering if there is a known or likely issue with this receiver (after this much time).
Also, is it worth having a receiver this old repaired? Any idea how a new 320bee or 325bee integrated (60 wpc) would sound in comparison (the 7400 is 100 wpc)? It is a great unit so I'm hoping I can have it fixed for not too much $$.
Send it to NAD repair. Ask for an estimate of cost before you proceed. If the channel is working but merely down in level, you will probably pay more for labor than parts.
I found an authorized service center not too far from me (I'm in DC), so I'm thinking of taking it there when I get a chance. I'd rather not have to deal with shipping it (cost/risks/time/etc).
Someone mentioned "the capacitor in the feeback loop of the amp to ground" - does this make sense to any knowledgeable people here?
Aslo is there a reason to worry that after I get this issue fixed it will happen again as all the caps start drying up? (Not close to an expert by any means, but I opened it up out of curiosity over the weekend and there are a LOT of capacitors in there!) I'd like to keep the unit and am willing to have it fixed, but not if it will be a recurring problem.
It's not unusual for any 15-20 year old amplifier to require service for various issues. Capacitors dry out and leak, resistors drift, noises creep in that weren't there before, etc. The NAD is like any other vintage product, you have to decide how much you want to put into maintenance or whether you would rather buy a new unit. There's no real way to foretell failure in most components. You can have all the caps replaced and that will probably give you another 20 years of mostly trouble free service. You will pay dearly for the labor on that job! I would prefer to have something new when I'm not dealing with a truly classic component. You'll have to decide whether the NAD is a "classic" component in your estimation. Go listen to some new gear and decide whether what you hear is worth buying rather than repairing the NAD.
To answer your question regarding the cap in the NFB circuit, yes, it could be that cap. Or, it could be a cap in the power supply or a coupling cap in the audio circuit or even a cap in the muting circuit. If it's not a cap it could be a resistor. Or it could be a cap that has fried due to a resitstor that has drifted off spec. Let a tech look at it and give you an estimate.
TMan, like Jan said, take it to a tech. NAD charges 60 dollars CDN per hour which of course can get pricey, but a cap replacement should only be an hour work TOPS, and the caps NAD uses are not that expensive due to the fact they use mid range caps from China. Shouldn't be expensive. If It were me, I too would agree with Jan, and would probably buy something with a warranty.Cheers.
Thanks for the replies. I'll take it to the shop when I get a chance. Hopefully it won't be too bad. Think I'll take the chance on this unit for now since I have a feeling I'd have to spend a lot more than the $300 I paid for it (6 years ago or so) to match the quality.
tman, you might be surprised by the goodies you can get for 300 skins today. Add the advances in features, and...
remember that a blown componant affects all the other bits in a circuit. Replaceng a cap or a resistor does not reach to the other componants in a chain that could be damaged.
Yeah Nuck, I've been curious about the latest NAD integrateds (like the 320/325bee) - I wonder how they would compare with the 7400.
But with 100 WPC with 5.7 dB headroom, and a nice tuner and phono section (even though I don't have a phono hooked up at the moment), I'll have the 7400 looked at. Hopefully it won't be too much to get it back in shape.
Hello, I have a NAD 7400 that has a low signal output on the left channel. I have equal level into the amplifier stage, but have yet to isolate the defective component, has anyone done component level repair for this problem? I would appreciate any help. Thank You, Bberry