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OPERATIONAL MANUAL
FRONT PANEL LAYOUT (ALL VERSIONS)
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CHANNEL I – EF86 PREAMP
1. INPUT JACK SOCKETS
Guitar input jacks into the EF86 channel. These are wired in the traditional way that gives a 6dB
difference in gain between them. The socket nearer the front of the amp is the higher gain, the
one nearest the rear of the chassis is 6dB quieter.
2. VOLUME CONTROL
Controls the volume level of the EF86 channel.
3. BRILLIANCE SWITCH
This is based on the original tone altering control from the original AC15 which basically was Off
or had a massive bass cut function (which by its nature made the sound “brilliant”, but no bass).
We felt that the two original positions were too extreme, so we have expanded this to have three
positions, the new position being like the early AC30 “TREBLE” amps. So the function now is: -
OFF = flat response, 1 = treble (new position), 2 = brilliance (original circuit)
4. BASS SHIFT
Position 1 is the original bass response, whilst position 2 gives a tighter bass response which is
useful for high volume use to prevent the tone getting too muddy.
5. EF86 MODE
This switch re-configures the EF86 valve from Pentode mode to Triode mode. Triode mode will
give a lower gain tone with higher headroom. Pentode mode is the original mode and has a very
sweet high gain tone with not very much headroom.
