Octave HP 300 SE, Owner'S Manual

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9. Tubes
9.2. Replacing tubes
Please use only original OCTAVE replacement tubes. These have been selected and tested for
use in our amplifiers.
Important! Changing tubes is a job for a qualified technician!
1. Switch off the preamplifier, unplug the power cord from the wall socket, and allow the unit
10 minutes to cool down.
2. Take off the cover by removing the M 3 screws, (10 pc.)
3 . Take out the old tubes.
Carefully remove the tubes from their sockets, taking care not to exert sideward pressure
on the sockets.
4. Fit new tubes
Please ensure that the tube pins are all perfectly straight before inserting your new tubes.
Straighten any bent pins very carefully by hand if necessary.
5 . Cleaning tips
Cleaning agents and contact cleaners are not recommended for tube sockets. Clean dirty
sockets with compressed air and carefully clean tarnished tube pins using a wire brush.
6. Please note:
No adjustments are necessary to your amplifier after fitting new tubes.
It may take new tubes some time (up to 300 hours) to achieve their optimum sound quality.
Manufacturing faults in tubes may only become evident after about 100 hours of use. You
should therefore be wary of installing untested tubes. However, faulty tubes or tubes of the
incorrect type will normally not damage the amplifier.
9.3. Tube service life
 Thanks to the protection circuits and soft start electronics, the tubes used in your amplifier
should achieve an average service life of
5 - 10 years .
 Because the tubes have different service lives, it should never be necessary to renew the
entire tube complement at the same time.