Lightning Boy Audio 1401 User Manual

Congratulations on an excellent purchase! This guide was put together to help you get
the most out of your investment.
The 1401 Stereo Microphone Amp (AKA 1401 Preamp) was designed to serve as the
output amplifier for the LBA 1401 Analog Plate Reverb. Though it's features are
specifically designed to serve this purpose, the 1401 Preamp also works exceptionally
well as a stand-alone mic preamp for dynamic microphones and vacuum tube powered
condenser mics. By adding on the LBA Ghost Box, the 1401 Preamp can be used as a
preamp for any microphone.
Getting Started:
Carefully unpack the 1401 Preamp. Be aware that there is glass in the package, so
proceed with caution. You will find 3 metal tube shields, and small boxes containing the
vacuum tubes. Carefully remove the vacuum tubes from their boxes. Align the pins of
the vacuum tubes with their respective sockets on the back of the 1401 Preamp and
insert it into their sockets. Next, the tube shields will need to be attached. Slide them
over their respective vacuum tubes and rotate into their locked position. There are little
nubs on the tube sockets to lock the shields in place. You can then plug in the power
cable and rack mount the 1401 Preamp.
Powering Up:
The power switch is located on the front panel. Once engaged, it will take about 30
seconds for the tubes to warm up enough to pass audio. While the 1401 Preamp will
start working within 30 seconds, it will require at least 10 minutes of warm up time to
sound its best. To power down, just turn it off. Nothing fancy here.

Controls:

The Front panel offers independent controls for Gain and Treble for two channels. The
Gain control comes before the amplifier stage in the circuitry. The Amp is configured to
run at 100% gain all the time, while the gain control allows for the input signal to be
attenuated before hitting the amplifier.
The Treble control is a feature particularly useful when using the 1401 Preamp as the
output amplifier for the 1401 Analog Plate Reverb. This control is a passive shelving EQ
circuit, which allows one to subtract high frequencies from the signal. With the treble
control turned all the clockwise, the treble EQ circuit is bypassed. This control is
designed to allow the user to darken the sound of their plate reverb if so desired.
Lightning Boy Audio
1401 Stereo Microphone Amp
Users Guide 2014