After carefully removing the chassis from the cabinet, turn the amp on (in standby) and let it heat up to normal operating temperature. Make sure you have it connected to your speaker cabinet!
Refer to the image below. Take the amp off of standby. Set your multimeter to measure mA.
Connect the black chord (ground) to the metal part of the amps chassis. I purchased a clip at radio shack for this so I can just clip in on and forget about it.
Touch the red chord to either outer pin of the bias test points. Once you have adjusted the bias to within tolerance for your amp redo at the other outer pin. There is only one trim pot and it is used to adjust the bias on the right and left side.

    72 to 80mVdc per side (pins 1 and 3 of CON 10) with respect to chassis ground for the 2466.

  43 to 48mVdc per side (pins 1 and 3 of CON 10) with respect to chassis ground for the 2266 / 2266C.

One side may be slightly different to the other but just set the bias so that both readings are within the range quoted. Check it again after 5 minutes to ensure it has settled at the specified value.



Do not touch any other part of the amp

Great clear post and good clear graphics also. Thanks for the work on this.

thanks Slowpoke.  That's perfect