NAD 3150

The lamp will glow when you have bias current flowing. So not a problem.

Just remember to make sure the adjustment is still correct when on full mains as it can change with the higher supply voltage.

The centre pin of the resistor pack will go to the speaker output and so measuring from speaker + to that centre pin would always show as 0 volt. If the manual says to do it that way then it is wrong. You have to measure across one of the resistors which you seem to be doing.

8mv will about 36 milliamps current

A buzz :D a loud buzz, a quiet buzz. It needs quantifying and checking. Does it change with the volume control for example.


oh by the way the buzz dissapeared with those 10 loose joints;)
 
If the resistor is in series with a relay coil, sitting there running hot day in and day out, it could turn brown into violet easily. Discoloration is a sign of long term (over)heating. And if it does read 490 ohms that pretty much confirms that it’s running too hot - values tend to go *up*. Probably using 1/2 watt carbon film when they really needed 2 watt MOX or WW for long term stability.


it was def a 2w carbon installed
 

Mooly

Administrator
Paid Member
2007-09-15 8:14 am
mmm i will,eventualy, trouble is i have 17 nads yet to fix :eek:

So that is why the price has increased, shortage of supply 'cos someone is buying them all up :D

oh by the way the buzz dissapeared with those 10 loose joints;)

Well that's good :)

sorry yes composite

Composite as in carbon composition... NAD use those things? Carbon film is fine but not the other. That's very 1960's.

Carbon composition, you could keep it original:
 

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Mooly

Administrator
Paid Member
2007-09-15 8:14 am
More a case that the applications that used them have disappeared I think. Things such as line output stages on CRT based TV's although they do still turn up in switching power supplies which see the same very high voltage very fast rise time pulse waveforms. Thy do have their uses still.