The Rear Panel:
66
27. SPEAKEROUTPUT jacks: Using a
1/4” mono phone plug, connect the out-
put of the BT-350 to your speaker cabi-
net(s) via these jacks. Be sure to use
heavy gauge speaker cable – not instru-
ment patch cords – for these connec-
tions. These jacks are wired in parallel:
when connecting your speakers, keep
the total impedance at or above 4 ohms.
The chart below can help you determine
the total impedance load when connect-
ing various combinations of speakers in
parallel.
SPEAKER NUMBER OF TOTAL
IMPEDANCE SPEAKERS IMPEDANCE
4 OHMS 1 4 OHMS
8 OHMS 1 8 OHMS
8 OHMS 2 4 OHMS
16 OHMS 2 8 OHMS
16 OHMS 4 4 OHMS
28. AC Line cord: Firmly plug the sup-
plied, heavy-duty grounded power cord
into this receptacle. When in use, be sure
this cord is properly plugged into a safe-
ly-wired, grounded 120 volt, 60Hz AC
power outlet. Do not attempt to defeat
the ground connection on this cable!
If your BT-350 was purchased outside of
the United States, see the unit’s rear
panel for its power rating and follow the
above guidelines.
BIAMP OUTPUTS:
29.HIGH OUT: When used in the
biamp mode, this output connects to the
high-frequency power amplifier. See the
section entitled “Using the Biamp
Capabilities” on pages 8 and 9 for
details.
30. LOW OUT:When used in the biamp
mode, this output connects to the low-
frequency power amplifier. See the sec-
tion entitled “Using the Biamp
Capabilities” on pages 8 and 9 for
details.
NOTE: You may access the BT-350’s
internal power amp through the Effect
Return jack (#34), for either the high or
low signal. This is covered in the section
entitled “Using the Biamp Capabilities”
on pages 8 and 9.
LINE OUTPUTS:
31. UNBALANCED: This 1/4” mono
phone jack supplies an unbalanced out-
put signal for connecting to an external
power amplifier. Very short runs (under
20’) to a mixer or recorder having unbal-
anced inputs can also be made from this
jack; for longer runs use the Balanced
output (#32). The output level at this
jack is adjusted by the Line Out Level
control (#15) on the front panel.
32. BALANCED: This XLR-type con-
nector supplies a balanced signal for con-
necting to an external mixer, recorder or
power amp which has balanced inputs.
The output is adjusted by the Line Out
Level control (#15). Use the Balanced
output when the distance between the
BT-350 and the mixing console or
recorder is over 20’.
NOTE: The Balanced Output jack is
wired as follows:
PIN 1: GROUND
PIN 2: POSITIVE (+)
PIN 3: NEGATIVE (–)
EFFECTS LOOP:
33. SEND: When using an external sig-
nal processor with the BT-350, connect
a shielded cable between the Send jack
of the amplifier and the input of the
effects unit. This “sends” the pre-ampli-
fied bass signal to the device for process-
ing.
34. RETURN: When using an external
signal processor, connect a shielded
cable between the output of the effects
unit and the Return jack of the amplifier.
This “returns” the processed bass signal
to the BT-350’s internal amplifier.
BT-350
BT-350 ThunderBass Amplifier