Laney GH50L - Manual (Page 8)

REAR PANEL CONTROLS - CONTINUED
BIAS: This allows you to bias the amplifier to suit your chosen output tubes. The switch has two positions 5881/6L6 and EL34. We
recommend the use of matched sets of output tubes for best performance. Ensure the switch is in the correct position otherwise you
risk damaging your amplifier.
SLAVE OUT: The slave out gives the user an output for driving other amplifiers. This is useful in multi-amp setups where a single
preamp can drive several GH power stages. This can be done by simply daisy chaining SLAVE OUT’s to SLAVE IN’s. The Slave Out is
an (unbalanced) line level output.
SLAVE IN: The Slave in socket provides the user with an input to the power amplifier stage. The Slave in is only operative when the
FX switch is in Side Chain or Insert mode. When a Jack is connected to the Slave In socket the preamp signal does not pass to the
power amp.
FX RETURN LEVEL: This control serves two purposes.
1) In Side chain mode it controls the level of the FX Return signal mixed with the dry signal.
2) In Insert mode it behaves as an overall level control. (See 14)
EFFECTS LOOP RETURN: Connect the output from your external effects to this socket. The effects loop allows you to
connect external effects such as tremolos, chorus and delays to your amplifier. A portion of the signal leaves the amplifier via the
`Send’ socket and comes back from the effects unit via the ‘Return’ socket. A notable feature on the GH products is you won’t lose
sustain when the FX loops are in use. This is because the power stages are still driven by a tube FX loop buffer.
EFFECTS LOOP SWITCH: This allows the effects loop to operate in three distinct modes:
1) Side Chain: The return signal is mixed with the dry signal, the level of FX return is controlled by the FX return level control. This
allows you to set the right mix between the dry signal and the effects signal. (When the Effects loop switch is in ‘Side Chain’ mode the
Slave in socket is operative)
2) Insert: The return signal is buffered and sent directly to the output tubes, no mixing with the dry signal happens. The wet/dry mix
is adjusted within the external FX processor. The FX return level control then acts as overall level control allowing you to make up for
any insertion loss that may occur in the FX processor. Warning: In insert mode with the FX return level control at minimum the
amplifier will have no output, good normal level for this control is ‘5’ which is approx unity gain. (When the Effects loop switch is in
‘Insert’ mode the Slave In socket is operative)
3) Bypass: The FX loop circuitry is switched out of circuit altogether.
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