Just got a new power amp

PS Audio S300 is not fully balanced. "Bridged" output might suggest that, but it isn't a bridge of two amps but 4 Mosfet bridge to flip speaker direction between V+ and GND, since output is single voltage supplied.  Some class D modules, like Hypex, use dual +/- supply and only 2 output Mosfets.  S300 is based on 300AS1 Icepower module, almost identical to 200ASC (in my Rowland 102), but  with stronger output Mosfets.  Both my amps Benchmark AHB2 and Rowland 102  don't have RCA inputs.  

The most important thing is what you can hear.  Some features of XLR, like higher noise rejection or locking connectors with female input side (pins recessed - not exposed) might be very important in a large studio - not so much at home.

PS: Both speaker terminals have about 30V DC (half of supply) on them - do not short  either to GND.

 

@cleeds  It is amplifier with balanced input and not the "Fully Balanced Amplifier".  "Fully Balanced Amplifier" term refers to amplifier consisting of balanced input followed by two separate amplifiers - each driving one terminal of the speaker.

 

@cleeds   I don't see anything in specs showing fully balanced operation.  

Look at page 5, Fig 1  300AS1 datasheet  showing block diagram.  After balanced input, there is only one path (one amplifier).

https://shop.icepoweraudio.com/wp-content/uploads/2023/02/ICEpower300AS1_Datasheet_2_2.pdf

@cleeds   This amplifier has only balanced input.  Circuitry between input and output is not balanced and output is not balanced.  Output is single-ended, with Mosfet bridge to switch "flip" direction of the speaker.

@cleeds   Input stage can be either "balanced" or "true balanced".  "True" refers to inputs that are not referenced to GND, like in instrumentation amp or transformer.
When pre output and amp input are both "true" balanced signal to shield capacitance in cable disappears, since signal is not referenced to GND.  Example of such configuration is output transformer to input transformer.

Amplifier can have balanced inputs or balanced outputs (to increase power), but "Fully Balanced Amplifier" means that balanced input section (instrumentation amp or transformer) is followed by two separate amplifiers, each driving one speaker terminal.  Such configuration helps to improve common mode noise rejection and reduces even harmonics.

That is at least how I understand it.  Other terms like "fully balanced input" are also used, not to mention "rms power".  Most of the time I understand what they mean.
 

@invalid  S300 output is supplied from single supply only.  To achieve net zero output at 50% duty cycle speaker is "flipped" between V+ and GND by bridge of 4 Mosfet transistors.  Some modules achieve it with dual +/- supply and only 2 Mosfets.  To me it is more "bridged" than "balanced", but it doesn't matter, as long as we know what it is.

@cleeds   He talks about benefits of balanced cables and differential inputs.  It has nothing to do with "Fully balanced power amplifier" vs power amplifier with balanced differential inputs.   I will leave it at that.