V1, V2, and V3 (see tube chart on pg. 10)
To remove tubes, gently pull upward using a very slight circular motion if necessary. When re-
inserting a preamp tube, mind the pin/socket orientation as they are “keyed” to insure proper
installation.
Changing output tubes
V4, V5 (see tube chart on pg. 10)
CAUTION!: Tubes can become extremely hot during normal operation. Make sure the
amplifier is OFF, and always allow tubes to cool before handling to prevent burns.
In general, it's best to change both output tubes at once (V4, V5 – See tube chart on pg. 10),
and preferable to buy a "matched pair" from a reputable dealer. However, because of the dual-
bias system, it is possible to replace only one output tube, then balancing the bias level with
the existing output tube.
Tip: Buy “burned-in” tubes when possible for maximum stability and minimal bias drift.
To change tubes, remove the old tubes and set both bias controls all the way down (counter-
clockwise). Insert the new tubes minding the “key” on the bottom of the tube, and slowly
bring up both bias controls until they are equal and in the safe bias range.
If tubes are not pre-“burned-in,” check the bias after playing to see if it has drifted from the
initial setting. Full burn-in may take up to 24 hours depending on the tube set. This is why
burned in tubes are preferred.
Different tube types and bias ranges (50-watt version)
The Hellhawk 50W can use both EL34, 6L6, and KT88 output tubes. Below are the correct bias
ranges for all types:
•
6L6: 37mV to 43mV
•
EL34: 31mV to 36mV
•
KT88: 31mV to 36mV
Anything lower settings will not harm the tubes, but anything higher than:
•
41mV and up per tube for EL34s
7
Содержание Hellhawk 50W
Страница 1: ...1...
