Laney TT20 User Manual - page 10
Notes
Rear View
V1
V2
V3
V4
V5
V1 ECC83 Low Noise Type part # 005548A
V2 ECC83 Soft distortion Type part # 005570
V3 ECC83 General Purpose type part # 005548C
V4/V5 EL84 Matched Pair part # 005562
Solution 3
Replace the secondary fuse and turn on the power. View the output valves. If one valve fails to light up, replace that
valve. If the output valves check out ok, another cause of a blown secondary fuse is a damaged preamplifier valve. Start
with valve V1 and replace it, follow the above procedure. If the symptom persists, consult a qualified engineer, do not fit
higher rated fuses.
Symptom 4
No pre amplifier boost.
Solution 4
Replace pre amplifier tubes V1 or V2 or a combination.
Symptom 5
Slow loss of power
Solution 5
Check first for damaged output valves (glowing ,flashing or dead) by using the procedures described in symptom 3.
All of these trouble shooting procedures can be performed quickly, without the aid of any sophisticated test gear. We
suggest that you always maintain spare valves for emergency purposes. Keep your Laney free of dirt, dust and moisture to
prevent performance failure Never subject your valve amp to environmental conditions that would not be comfortable to
you!
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