Audio Research High Definition Reference 80S User Manual page 9

Tube cage removal and installation
CAUTION: THIS STEP FOLLOWED BY USER IS ALLOWED ONLY ONCE FOR THE INITIAL
INSTALLATION BEFORE POWERING UP THE PRODUCT FIRST.
Warning: Tube replacement shall be done by skilled or service personnel, or qualified
technician.
Important
The AC power supply cord must be disconnected from the amplifier before
replacement or installation of vacuum tubes.
To remove the cage:
Use the supplied 7/64" hex driver to remove the (3) cap screws and nylon washers at the
rear of the top cage, per illustration 1:
Illustration 1
Gently slide the cage to the rear. Then lift it up and off the chassis, per illustrations
2 and 3.
Illustration 2
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