Found some further spec on the head
Power Output: 200W RMS
Power Requirement: 230/115/100 V
Frequency response: -3dB at 35Hz and 14 kHz
Speaker Outputs: Speakon/Jack
High Instrument Output: Impedance 1m Ohms, input range 25mV - 1.5V p-p
Low Instrument Input: Impedance 100k Ohms, input range 25mV - 6V p-p
Line Input: Impedance 100k Ohms, input level 0dBu nominal
DI Output: 600 Ohms balanced, level 0dBu nominal
Speaker Outputs: 1/4" jack connectors for 4 and 8 ohm speaker cab configurations.
Effects Send: 1k Ohms, level 0dBu nominal
Effects Return: 1M Ohms, input level 0dBu Nominal
Pre-Amp Tubes: 1 x ECC83 1 x ECC82
Output Tubes: 1 x ECC83 4 x 6550
EQ: Fully Passive Middle, Bass, Treble, Mid Shift, Bass Shift, Bright
Mute: Mute the output of the amplifier (useful when tuning)
VU Meter: Visual indication of the output level of the LB-30