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HELP - NAD c370 issues

fuzzface

Standard Member
Hi,

I have recently bought a NAD c370 which appears to be in good condition. I am running it through some BMW 601 s2's using QED speaker wire (no plugs). The sound is terribly distorted and low volume.. I dont currently have a dedicated player so have been using IPOD's, digital television, and other such devices to test.

I have tried the same speakers and same players through an NAD Bee and had no problems.. the only thing that has changed is the amp and the speaker wire. When i twist the connecting wire going through the player this increases the distortion (I have tried replacing the wire with the same result).

The amp was bought from a reliable source who was using it with no difficulties until I bought it a couple of weeks ago.

Would the speakers be uncompatible. If anyone could help I would be very grateful as I am desperate to get this system working?

Kind regards,
David
 

fuzzface

Standard Member
Stage 2 of the amplifier saga:

Last night I tried to test the setup with a different amplifier (a very old Cambridge Audio) with the same problem occuring = very low volume and high levels of disortion.
So i tested all the cables, parts etc = everything seemed fine.

So i thought I would try it all again from the start but tried from a different side of the room with a different power point (for space reasons more than anything).

1) Firstly i plugged in the small Cambridge Audio amplifer into a different power point in a different corner of the room and it works!!

(2) So I try the NAD amplifier and it works 100% better than before (volume has returned)but it is still diistorting more than it should!

So it seems everything is working, so what is the problem? re-distortion

Could it be the mains coming out of our power circuit? - doesnt make sense as the tv, radio, computer etc all work out of both the power mains i used for the above tests.

]Is it a supernatural presence?

Please advise?

Many thanks,
David
 

fuzzface

Standard Member
Is this something a power filter (surge protector) may solve?

Please help as my NAD c370 is sitting unused under my desk.:suicide:
 

Arfa

Established Member
When you turn on the C370 and hear distortion, how long has the amp been on for? The amp takes a while to warm up (with little red led) then finally clicks on (led turns green). Now once or twice, mine has come out of the warm up phase early and sounded terrible, similar to how you describe. If you haven't done so already, try leaving it on for a while (half hour or so) and then see if it improves.

That power socket does sound a bit dodgy mind. Maybe grab one of them power usage meters from Maplin. As well as display watt usage, they display voltage and amps being drawn. Might be a good easy check.

Next swap in some different speaker cable, there could possibly be a stray strand shorting. Possibly not enough to trigger the short protection, but enough to act as a resister drawing all the current.

Other things to try are swapping the speaker terminals you connect to, try the zone B ones, in case there's a loose connection on the other terminals. Ditto for the input connectors to, try plugging your source to others.

Also double check you haven't got the 'bridged' mode enabled! There's also the soft clipping function, which you could try turning that off, if not already.

Finally if you're still having issues, pop off the top and inspect the big capacitors for bulging or leakage. If you have either, they're knackered/dying and a service with Nad will be in order. This amp does carry a warning about needed lots of ventilation, or risk it dying quite catastrophically!
 

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