• If you are replacing a power amp tube, ensure the
replacement tube bears identical specs.
• Use only matched pairs of power amp tubes.
• If you install a matched pair of tubes bearing precisely the
same specs as the original tubes, the amp does not have to
be re-biased. Conversely, if the specs are not identical, the
amp must be biased. Biasing is a complex procedure
requiring special tools and should only be executed by a
qualified amp technician.
HOW CAN YOU EXTEND THE LIFE OF YOUR TUBES?
• Never operate the EDITION TUBE without a proper load
(speaker) connected to the output.
Switch the amp off and let the tubes cool down before
transport. A quality flight case is a good investment and is only
slightly more expensive than a complete set of tubes.
• Proper bias and trim are essential. If you find the tubes need
to be replaced too often, consult a qualified technician.
All other EDITION TUBE components do not require
maintenance. Use a slightly dampened cloth for all metal
parts and the exterior surfaces. Avoid exposure to mechanical
shocks, extreme heat, dust and moisture. Ensure the cooling
vents are not obstructed during operation.
Here are a few more basic rules that will extend the service life
of your amp enormously if you follow them:
- Make sure all peripheral devices and connecting cables are
in a state of good repair! - Ensure plenty of air can circulate
around the amp’s ventilation slots at all times - your EDITION
TUBE’s life depends on it.- Definitely avoid exposure to
mechanical shocks and extreme heat, dust and particularly
moisture.
- Be very careful about the kind of peripheral devices you
connect to your amp and always check out their specs before
you plug them in. Never connect speaker cabinets with an
impedance (ohm) rating lower than the EDITION TUBE is
designed to handle. Under no circumstances should you
connect devices with high output signal levels (e.g. power
amps) to your amp’s input.
- Be sure the AC power source delivers the current that your
amp is designed to handle before you plug it in. When in
doubt about the local rating, ask the venue’s sound
technician or a stage hand.
- Refrain from DIY repairs! To be on the safe side, you should
also have a qualified technician replace internal fuses.
5.0 TROUBLESHOOTING
1) The EDITION TUBE is not getting any power:
• Check the mains cable to see if it is connected properly.
• The mains fuse may be defective. Replace the fuse with
another identical fuse. If this fuse also trips, consult your
Hughes & Kettner dealer.
2) The EDITION TUBE is connected properly, but no sound is
audible.
• One or several GAIN and MASTER controls may be turned all
the way down. Dial in a higher setting.
• A short circuit in the speaker signal chain may have tripped
an internal fuse, or one of the power tubes is defective.
Replace the speaker cable and have a qualified service
technician replace the fuse/tube (identical specifications
are a must). Please read Section 4.0 on how to replace
tubes correctly.