Rear Panel
1. Mains Fuse
The value of the Mains Fuse is specified on the rear panel. Never use a fuse of the
incorrect value or attempt to bypass it.
2. Mains Input
The supplied detachable mains lead is connected here. The lead should only be
connected to a power outlet that is compatible with the voltage, power and
frequency requirements stated on the rear panel. If in doubt get advice from a
qualified technician.
3. H.T. Fuse
The value of the H.T. Fuse is specified on the rear panel. Never use a fuse of the
incorrect value or attempt to bypass it.
4. Speaker Outputs
The output marked '1x16 Ohm' is for the connection of a single 16 Ohm extension
speaker cabinet. (or the internal loudspeaker of the HT Studio 20 combo).
The outputs marked '1x8 Ohm or 2x16 Ohm' are for the connection of either a single
8 Ohm extension cabinet or two 16 Ohm cabinets. Also, the internal loudspeaker of
the HT Studio 20 combo can be plugged in here if it is used with a 16 Ohm extension
cabinet. See table below.
Internal 16 Ohm combo speaker
Internal 16 Ohm combo speaker
plus one 16 ohm extension cab
One 16 Ohm extension cabinet
Two 16 Ohm extension cabinets
Single 8 Ohm extension cabinet
WARNING: The output marked '1x16 Ohm' should never be used at the same time
as any of the outputs marked '1x8 Ohm or 2x16 Ohm'. Failure to correctly match the
impedance of the amplifier and speakers, will damage the amplifier.
5. Speaker Emulated Output
This output emulates the tonal characteristics of a guitar speaker cabinet and
provides a natural valve overdrive tone for connection to a recording device or mixing
desk. Always use a good quality screened lead.
NOTE: To record 'silently', simply set the master volume to zero. You may also
record from this output without a loudspeaker connected, but ensure that no
loudspeaker leads are connected to any of the loudspeaker output jack sockets of
the amplifier, as this will defeat the load protection circuit and will cause damage to
the amplifier.
6. Effects Loop Return
Connect the (mono) output of an external effects unit here.
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'1x16 Ohm' output
'1x8 Ohm or 2x16 Ohm' outputs
X
X
X
X
X
X
X
X
7. Effects Loop Send
Connect the (mono) input of an external effects unit here.
8. Effects Loop Level
The Effects Loop Level switch sets the effects loop to either +4dBV/-10dBV, which
enables you to use it with either professional equipment (+4dBV setting), or with
guitar level effects such as effects pedals (-10dBV setting).
9. Footswitch
The supplied footswitch is connected here. The footswitch enables you to switch
between the Clean Channel and the Overdrive Channel.
NOTE: Overdrive Select switch (Front Panel 5) must be in for the footswitch to work.
Technical Specification
HT Studio 20 Combo
Power (RMS): 20 Watts
Valves: 2 x ECC83, 2 x EL34
Weight (kg): 20.4
Dimensions (mm): 574 x 528 x 290
Footswitch: FS-4 supplied
HT Studio 20 Head
Power (RMS): 20 Watts
Valves: 2 x ECC83, 2 x EL34
Weight (kg): 12.8
Dimensions (mm): 517 x 288 x 274
Footswitch: FS-4 supplied
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