Both amplifier units are identical and by default they provide for an amplifiction of 24dB, though you can change each channel´s amplification to 12dB, 24dB or 36dB. LEDs show when the signal is about to clip and speaking of which: the distortion sounds "clean" and good.
Besides the use as a preamplifier for external line signals you can of course use the module to compensate for level loss (e.g. after filtering). The attenuators are AC-coupled and can be DC-coupled by a jumper.
The module not only has good amplifier-ICs but also sealed and enclosed potentiometers and sockets. :)
Per amplifier unit there´s one input and one output socket, each 3.5mm (1/8") mono.
3U Eurorack module, 4HP wide. Current draw max. 20mA