Palmer main Passive 2-Channel Line Merger

Description:

Sometimes it is necessary to send two stereo signals to one device, for example, when two mixing consoles have to drive a stereo power amplifier. In practice, this is rarely possible without ground loops occurring. The Palmer main solves this type of problem. It mixes two stereo input signals via a resistor matrix, whereby the input pair A is galvanically isolated by a transformer in order to avoid ground loops.

The Palmer main works purely passively. The result is a particularly low noise floor and a neutral sound. Thanks to large transformers, it can handle high-level signals up to +20 dBu without distortion. The transformers also make it possible to assign the input pair A unbalanced while the output signal remains balanced.

The passive mode of operation without a power supply makes the Palmer main particularly reliable and failure-proof. The aluminium/steel housing and XLR sockets are also best suited to the rough everyday life on stage. The Palmer main merge box solves typical sound reinforcement problems in the simplest way with uncompromised sound quality.

Features:

Merge two stereo signals on one output pair
Allows the combination of two devices, e.g. two mixers to a PA System
Galvanic transformer isolation of outputs
Switchable ground lift to isolate ground loop hum
Neutral sound
High headroom (+20 dBu max. input level)
Passive construction, no power supply required
Extremely fail-safe
Solid casing made of aluminium and steel
Engineered in Germany

Specifications:

Line summing unit
Channels 2
Type passive
Transformer isolated Yes
Inputs 4
input type balanced
Input connectors XLR
Outputs 2
Output type balanced
Output connectors XLR
Ground lift switch Yes
Housing Aluminium continuous casting
Dimension (H/W/D) 140 x 50 x 128 mm
Weight 0,8 kg
Ambient temperature during operation -20 - 70 °C
Relative Humidity < 80 %, not condensing
Accessories (included) Inscription label (tour label), rubber feet
Audio
Max. input level (< 1% THD, 20 Hz) +20 dBu
Max. input level (< 1% THD, 1 kHz) + 32 dBu
Frequency response (±1 dB, relative 1 kHz) 10 Hz - 80 kHz
Input impedance (1 kHz) 3.3 kOhm
Output impedance (1 kHz) 600 Ohm(s)
THD (30 Hz, +4 dBu, unity, unweighted) < 0,9 %
THD (1 kHz, +4 dBu, unity, unweighted) < 0,02 %
IMD (SMPTE) (60 Hz / 7 kHz, 4:1, +4 dBu) < 0,015 %
Transformer ratio 1 : 1