The Signal Path:
The LUNCHBOX
Acoustic
has two main channels, one for your acoustic INSTRUMENT and one
for your favorite MICROPHONE. The Instrument channel has a standard ¼” jack on the top panel
feeding a Hi-Z preamp for tonal compatibility with most acoustic-electric pickups. The Microphone
input has two jacks on the rear panel, a standard ¼” and an XLR with switchable 12-volt Phantom
Power. These feed a Lo-Z preamp to capture the full dynamics of your microphone. All the main
inputs are protected against RF interference and ground-error overloads. The Instrument and
Microphone preamps feature separate analog GAIN controls on the top panel for easy adjustment
of each channel’s input sensitivity.
Following the analog input preamps, the signals are converted to 24-bit PCM digital at a 44.1
KHz sampling rate. In the digital domain, ZT’s proprietary dynamics and EQ signal processing
are implemented. Also, channel-specific TREBLE and BASS tone controls with characteristics
closely following a vintage stack are applied. Additionally, the LUNCHBOX
Acoustic
has individual
REVERB controls, offering the option of different signal echo & decay for Instrument and
Microphone channels. At this point, the signals are converted back to analog and routed to the
selectable FEEDBACK CUT circuit.
The final preamp stage mixes the Instrument and Microphone channels with the stereo AUX
INPUT (
1
/
8
” jack on rear panel) and routes them to the buffered EFX loop. The EFX SEND can be
used as a DI or Line output without interrupting the LUNCHBOX
Acoustic’s
internal signal path.
However, plugging into the EFX RETURN will disconnect the internal signal path, replacing it with
the output from your effects. Finally, an analog master VOLUME is applied to the mix just before
sending it to the power amplifier.
The output amp section is carefully designed to constantly adapt to the signal characteristics
and the instantaneous power supply behavior. The amp itself is a pair of Class A/B output
stages, running fully bridged across the speaker load. The result is very high RMS power, with
extraordinary additional peak power on top of that. We feel this is the only way to deliver the
demanding dynamics of acoustic instruments to your audience. The LUNCHBOX
Acoustic
includes an adjustable HEADPHONE output and a switchable EXTERNAL SPEAKER jack on the
rear panel (8 Ω minimum).
Main Inputs
:
The ¼” INSTRUMENT channel input is located on the top panel of the LUNCHBOX
Acoustic
. This
input is shorted when not in use to reduce noise.
The MICROPHONE channel inputs are located on the rear panel of the LUNCHBOX
Acoustic
.
Both ¼” and XLR Microphone inputs are provided, with switchable Phantom Power on the XLR
input.
Phantom Power:
The LUNCHBOX
Acoustic
Microphone channel offers a 12v Phantom Power feature. If you are
using a condenser microphone, set the Phantom Power switch to On and connect it using a
standard XLR microphone cable.
