Bias adjustment in Cary SLI-50 integrated amp

I purchased a Cary SLI-50 integrated amp in 1997 and recently replaced the output EL-34 tubes, which requires bias adjustment. The amp has two bias adjustment jacks but does not have adjustemnt screws, like the latest model - SLI-80. I don't know how to make bias adjustment. I can insert a multimeter but cannot make an adjustment, because there are two grey round-shape plugs each located near the respective bias adjustment jack instead of adjustemnt screws.
Can anybody advise me how to make an adjustment?

Best regards,
I had SLI-50 and 80 in the past, they both had bias screws to adjust bias. SLI-50 is not auto bias as far as I know, you should take a picture from top and maybe one of us can help you point out where the bias screws are.
Actually, the SLI-50 is auto biasing and you should be fine as it runs in true class A mode. The SLI-80 does have bias adjustment and runs in AB-1 mode and is switchable from Triode to Ultra Linear Mode for different power requirements. You can call Kirk which is never a bad idea for peace of mind.

Good Luck,

I own the sli-50 also. Auto biasing acording to Kirk and the owner's manual.