VALVE REPLACEMENT AND TROUBLE SHOOTINGPS
The valves in your new valve amplifier will eventually need replacing due to wear, this is normal with valve amps. In most
instances you should be able to effect valve replacement yourself without incurring the costs of a service engineer. Following are
some of the most likely symptoms of valve malfunction and a suggested method of correction.
Normally valve amps give optimum performance when fitted with matched sets of output valves as factory fitted to all
Laney
valve amps. NB: Damage will not occur by not fitting matched sets although the amplifiers performance may be impaired.
SOLUTION 2
SYMPTOM 2
SOLUTION 1
SYMPTOM 1
Power light illuminates, no sound out put
Check time delay POWER FUSE and replace if necessary:-
LC30 : 230V T630MA Time Delay. 115V T1.5A Time Delay
LC50 : 230V T2A Time Delay. 115V T5A Time Delay
Amp connections have been performed correctly but power light fails to illuminate
Check secondary HT fuse and if blown replace with T 500MA (LC50) T250MA (LC30)
SYMPTOM 3
Secondary HT fuse (T500/250MA) blows repeatedly. This is a strong indication of a damaged output valve. The chart below
shows the valve layout and the function each performs.
V5
V4
V5
V1
V2
V3
VALVE IDENTIFICATION LC50
VALVE IDENTIFICATION LC30
V1
V2
V3
V4
V6
V6
V7
V8
V1 = Clean channel stage, ECC83
V2 = Second gain stage, ECC83
V3 = Third stage gain, ECC83
V4 = Phase splitter ECC83
V5 = Output valve EL84
V6 = Output valve EL84
V7 = Output valve EL84
V8 = Output valve EL84
V1 = Clean channel stage, ECC83
V2 = Second gain stage, ECC83
V3 = Third stage gain, ECC83
V4 = Phase splitter ECC83
V5 = Output valve 5881
V6 = Output valve 5881
USEFUL HINTS AND TIPS
VALVE REPLACEMENT AND TROUBLE SHOOTING
4:
Connecting your guitar to either the 'HI' or 'LO' input has an effect on the sound, regardless of the guitar type/pickup
configuration. The 'HI' socket provides more gain and extended treble, but with less BASS. The 'LO' socket provides a full
range signal with extended low frequencies and lower gains. You should experiment with both inputs to find the one which suits
your guitar, style of playing and gives you the most tonally pleasing results.
5:
When using the 'BRIGHT SWITCH' on the amplifier keep in mind that it has a greater audible effect the lower the amount of
distortion produced by the preamplifier. At some distortion levels the 'BRIGHT SWITCH' may appear to have no effect at all.
The following hints and tips are provided so that you can get the best performance out of your
Laney
valve amplifier. These are
only guidelines and should be adapted for your own preferences:-
1:
Valve amplifiers take a short time to 'warm up' to optimum operating temperature. To get optimum performance out of your
LC30/50 allow the amplifier to 'warm up' for three mins. before you begin playing.
2:
The position of an amplifier in a room has an effect upon the overall sound characteristics. If you wish to increase the bass
response of your amplifier place the amplifier on the floor. If you wish to reduce the bass response of your amplifier place the
amplifier on a stand.
3:
Do not place you amplifier hard up against a wall as this will reduce the air circulating around the back of the unit and may
result in overheating.
Laney
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