Help! Rotel rb1080 bias setting

[birdyman]

Can anyone tell me what is recommended bias voltage for Rotel RB1080?
Thanx in advance.

[sakis]

adjust VR 601 while monitoring voltage between TP1 and TP3 for 7 mv (millivolt ) reading for one chanel

adjust vr 602 while monitoring voltage between TP2 and TP4 for 7 mv ( millivolt ) reading for the other chanel

regards sakis ( information for the available service manual )

[Ian Finch]

Hi Sakis, wrong thread etc. but RA 1060 Rotel - similar? There's no urgency, its an old job never completed.

[sakis]

Originally Posted by Ian Finch

Hi Sakis, wrong thread etc. but RA 1060 Rotel - similar? There's no urgency, its an old job never completed.

sure Ian ....what can i do for you ??? service manual or adjustment procedures ??

[Ian Finch]

Wow, that was quick, quick service hehe.
It was the bias setting which I stupidly didn't check for before replacing output Txs.
I thought you may have had this one in the file for RB1080 too. thks

[sakis]

well Ian its not the exact same thing ...see attachment please that is a part of the service manual ... ( e mail me i f you want it ) ( for the 1060 ...its not in the same file with 1080 works diferent )

kind regards sakis

[Ian Finch]

I think with those figures and warm-up note it should be fine thank you very much, Sakis. I had presumed 12mv and now I know better. Thank you too for the offer of manual details. Can I offer you a beer or would you like something better?

[sakis]

i am fine Ian thanks....i would be actually tempted to listen to it either way 5 or 12 mv and for sure it will run hotter with a bit nore bias ....

often if i service amps that are supposed to used from normal people and no party animals i try to keep that bias up ( up means to a reasonable up )

kind regards sakis

[sakis]

just been looking at the schematic of the 1080 and i ve seen that is a 200w very symmetric and inetersting amplifier but still doesnt use any vi limmiter for the output section nice approach for a hifi machine but not really safe for this ammount of power ...

if the power supply is good that design will easilly produce 200w at 8R and almost double at 4 ( even though specs say 300 and that is not really possible without any limmiting )

so either the supply is poor or the estimation is academic

still remains an interesting amplifier

[birdyman]

Originally Posted by sakis

adjust VR 601 while monitoring voltage between TP1 and TP3 for 7 mv (millivolt ) reading for one chanel

adjust vr 602 while monitoring voltage between TP2 and TP4 for 7 mv ( millivolt ) reading for the other chanel

regards sakis ( information for the available service manual )

Thank you for your quick reply.