WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
There is a hole on the side of the unit which accepts a small screwdriver for tuning. You have probably not seen this hole When I was working on mine (many years ago), I was quite surprised to find this hole.
If you call up AR, they will most likely send you a service manual, especially if you can provide a serial number.
It is best to use an Oktet 6550´s and set the current through each tube to 65 mA, thats a dissipation of 32 Watt/tube. The holes on the side are for Servo Balance Calibration (Very difficult and time eating) Can copy the Adjustment prodedure.
Thanks for the all reply. I would liike to know is ARC havent the e-mail address? Becoz I cant find any e-mail on their website! And I think I better to ask for the service guide from them. Also I would like to order some spare parts for the CL60 and the SP11!!! Like the know and the power switch.... easy damage man!
Ofcoz I still want to ask for the circuit who can be help!