The FAB3110 – Output Transformer Module is designed for PCB mounting of typical output transformers like the Cinemag CMOQ-2S and compatibles. These type of transformers are commonly used in “API-type/style” preamps.
You typically connect the FAB3110 Output Transformer Module after your amplifying module (FAB4000 series modules). That way, your processed/amplified signal chain will go first through the output transformer.
A FAB3010 XLR Ouput Module could then be connected after the FAB3110 Output Transformer Module.
An optional “load resistor”, RLS, can be connected to the transformer’s secondary winding. One typically use a 600-ohm resistor at this point to properly load the output transformer. This “loading” can reduce the “ringing” and “overshoots” of square waveforms. Of course, you are free to experiment what resistor values sounds good to your ear, or you may want to not use any loading at all.
The output transformer has dual primaries and dual secondary windings. The output transformer is wired 1:1 for a net gain of 0dB for normal operation.
However, the FAB3110 Output Transformer Module also includes a Logic-controlled Relay to let you easily change the transformer ratio to 1:2. This is done by switching out the 2nd set of primary winding, while keeping the two (2) secondary windings in series connection. This basically gives you a 1:2 transformer ratio (i.e. doubling your signal output, or 6dB additional “free” gain.)