Rotel RA-980BX

[Carlosraj]

Hi,

I am having a problem with this amp. This amp does not have a balance pot but individual volume pots. The problem is the right channel is much softer than the left. If I set the left channel level at quarter, I have to set the right channel level at more than half to make it sound balanced. I checked the volume pot (50KA X 2) and it is OK. I removed the 2 links between "pre out" and "main in" and plug a signal into the 'left main in" and 'right main in' and the left sound louder than the right. I guess it means that it has nothing to do with the "pre out". I checked all the components on both the power amp boards, all seem to be OK except that resistor R669(10 ohms, 3 watts) has blown, but this resistor is on the left channel which is working OK. I am confused. Can this resistor be the problem. Please help.

Thanks

Carlos

 

[JonSnell Electronic]

That sounds like the amplifier has reduced gain and the 'good' channel has a burnt out Zobel resistor. Check the feedback decoupling capacitor.

 

[Carlosraj]

That sounds like the amplifier has reduced gain and the 'good' channel has a burnt out Zobel resistor. Check the feedback decoupling capacitor.

Will do. Thanks

Carlos

 

[Carlosraj]

Will do. Thanks

Carlos

Hi JonSnell,

On checking again, I realised that I have overlooked another resistor that has also blown. R620 (562 ohms) on the problematic channel was open, after replacing it now the amp is back to normal.

Many Thanks

Carlos

 

[dimliakos]

You are a life saver! I had the exact same problem after a recap atempt and I was hopeless. I checked every single cap diode and resistance..Lots of work.. I can believe how I missed that little resistor...Not the amp works fantastic.. Thank you for shareing...