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Thread: NAD 7400 weak left channel - any likely causes? Worth repairing, or get new integrated? |
    
New member Username: Tman202
Post Number: 1
Registered: Feb-08
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| Posted on Monday, February 25, 2008 - 03:11 pm: |
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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 $$.
Any help is appreciated! |
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Platinum Member Username: Jan_b_vigne
Dallas,
TX
Post Number: 12308
Registered: May-04
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| Posted on Monday, February 25, 2008 - 03:55 pm: |
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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. |
New member Username: Tman202
Post Number: 2
Registered: Feb-08
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| Posted on Monday, February 25, 2008 - 04:06 pm: |
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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. |
Platinum Member Username: Jan_b_vigne
Dallas,
TX
Post Number: 12309
Registered: May-04
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| Posted on Monday, February 25, 2008 - 06:08 pm: |
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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.
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Platinum Member Username: Jan_b_vigne
Dallas,
TX
Post Number: 12310
Registered: May-04
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| Posted on Monday, February 25, 2008 - 06:12 pm: |
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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.
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Gold Member Username: Nickelbut10
Post Number: 1233
Registered: Jun-07
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| Posted on Monday, February 25, 2008 - 07:58 pm: |
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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. |
New member Username: Tman202
Post Number: 3
Registered: Feb-08
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| Posted on Tuesday, February 26, 2008 - 09:55 am: |
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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. |
Gold Member Username: Nuck
Post Number: 9832
Registered: Dec-04
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| Posted on Tuesday, February 26, 2008 - 09:00 pm: |
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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.
Just sayin'... |
New member Username: Tman202
Post Number: 4
Registered: Feb-08
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| Posted on Tuesday, February 26, 2008 - 09:14 pm: |
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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. |
Platinum Member Username: Jan_b_vigne
Dallas,
TX
Post Number: 12314
Registered: May-04
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| Posted on Tuesday, February 26, 2008 - 11:06 pm: |
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If the 7400 only has a bad output, you can still use the tuner and phono section as outboard devices into another intregrated amplifier. |
New member Username: Bberry
St Paul,
MN
Post Number: 1
Registered: Jun-08
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| Posted on Friday, June 06, 2008 - 07:04 pm: |
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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 |
