RSX 1065 needed critical adjustment

[Rob Baker]

Hi everyone....Have a question. I have a 4 year old RSX 1065 thats really been a great unit. I resently had a EPROM and Firware upgrade. Not long ago the unit started acting up by running hotter then it every had before and the cooling fans would run only after 15 minutes of very light use. Really the fans never came on before even when pushed. I just got my unit back a few days ago after the local Rotel dealer could not fix the problem and it had to be sent to Rotel USA to have the tech's there repair the unit. The explaination for problems where that a "critical adjustment" had to be performed to the Bias of one of the channels. They ran a test with the unit at volume 72 all channels driven for one hour and the unit is now working fine. After having the unit running at home for a couple hours it's working great again. CAn anyone explain to me what happened to my unit...what it is they actually did to repair it and what can i do to prevent this from happening again ?

Thank.....Rob.

[Kevin D]

Not sure what would have caused it to change, but I believe the BIAS settings deal with the transition of the amp from class A to class B. Class B has downsides at low volume, and class A has issues with heat at high power.

Sounds like the bias was set to leave it in class A mode longer then it should be, causing the increased heat.

I would imagine it was some type of part failure that caused the BIAS level it was set to to no longer be correct, but I suppose it could be easy for a borderline setting to drift into a wrong setting over time.

Kevin D.

[Rob Baker]

Thanks Kevin....i really had no idea what they meant about Bias settings