SAM-A1 Owner’s Manual
FSL0132
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FSL0132 Version 5.1 © 2020 Fireworks Solutions Limited Page 6
3.1.
Equipment Operating Specifications
WARNING Operating the SAM-A1 outside of its stated operating limits can result in premature
failure of the equipment and in severe cases may result in the equipment overheating with a
subsequent risk of fire. These operating specifications must not be exceeded.
3.1.1.
Power Supply:
Mains input: Fused IEC Plug
Voltage:
205 to 255Vac – internally selectable – this is NOT automatic. In the true spirit of
old valve equipment, the unit must be set up for your mains voltage, see below.
Frequency:
48-62Hz
Power:
Nominal 70W depending on configuration, maximum 150W.
Insulation: Class 1 Protective earthed enclosure.
Fuse rating: 20 x 5mm HBC fuse rated at 2.5AT (delay)
IP Class:
IP20
Temperature: Min 0
o
C Max 40
o
C Operating and storage.
Humidity:
30 to 70% Relative Humidity.
The input voltage is compatible with BS7671, requiring a range of 10% -6%, 216V to
253V. The SAM-A1 will operate from 205 to 255Vac in, the input range is internally selectable for
the following supplies, with considerable overlap between the ranges: Blue is Neutral, primary Live
winding wires as follows:
210 ±5V:
Violet
220 ±5V:
Grey
230 ±5V:
Red
240 ±5V:
White – This is set as the default; good for around 225 – 253Vac in*
250 ±5V:
Black
*If the mains supply is too high for the selected input, the amplifier will get hotter (rear plinth),
wasting energy. The valve heaters will be run hotter and depending on the valves chosen, maybe
even too hot (this will reduce the life of your valves) – There is significant overlap between the
input ranges but for optimum performance and valve life, we strongly recommend the mains input
transformer winding is matched to your supply.
If the input is too low the regulators in the PSU may start to allow hum through to the speakers.
The input range is selected by connecting the appropriate input winding of the mains transformer
to the mains switch, with the alternative taps being terminated in female fast-on crimp connectors
and cable-tied back to retain them out of the way, the primary wire colours are identified above.
Input Voltage selection should only be performed by a competent technician capable of doing the
job safely and leaving the equipment in a safe state for use; alternatively, see FSL service section.
3.1.2.
Signal Input
One pair of RCA Phono sockets; isolated from chassis.
Input impedance:
90 to 100kOhms.
Input sensitivity:
200 to 500mVrms for full power out (dependent on configuration).
3.1.3.
Signal Output
Two pairs (right and Left) isolated from chassis 4mm sockets with binding posts for wires.
Output impedance: 8Ohms PASSIVE speakers only. It will work with impedances from 4 to
16Ohms but the SAM-A1 output is balanced with an 8Ohm load.
Output Voltage:
Max 26.5V pk-pk at 11Wrms in to 8Ohms (dependent on configuration).
Output Power:
8Wrms per channel (default) 16W peak (22.6Vpk-pk).
Bandwidth:
5Hz-50kHz -1dB at 1Wrms
Frequency response and distortion dependent on configuration.
