Okay to use RCA adapter on a fully balanced amp?

Here’s the part that concerns me about this amp possibly not having a "true" differential input, despite earlier verbiage:

If a balanced connection cannot be used, note that the amp cannot be driven to full power from a 2-volt single-ended output, the limit of most receivers. You leave half the power on the table.

@mulveling According to their website, the amp is fully differential and balanced from input to output. Its a bit hard to imagine, but it is possible that the input stage has a really poor CMRR (Common Mode Rejection Ratio) which would cause it to be more distorted and lower power when run with a single-ended source. But its hard to imagine that they would know to do balanced and get the CMRR thing so bad in that light- although I have seen that sort of thing happen.

At any rate it won't hurt to try! If the CMRR is anywhere near what we've been getting with our amps over the last 45 years it won't be any problem at all.

I have experienced what the OP is talking about. That is why I purchased the active adapter in my previous post

My amps are fully balanced and there is no issue with using them with RCA to XLR adapter. 

The adapter grounds one of the differential inputs to ground and then the amplifier behaves like a single-ended to the differential converter.

The gain of the amplifier does not change and it requires 5V input to get it to full power. This is an issue with standard RCA 2V outputs as 2V will get you less than 1/4 of the amps rated output power.

This is why I recommended to most my customers to get my active RCA to XLR converter that @evank refers to above. With 8dB of gain, it takes 2V up to 5V.  

@orchardaudio Most preamps can do 5Volts easily as long as the input impedance of the amp isn't an issue! My recommendation is thus to simply try it.

@atmasphere I agree in this scenario, the input impedance on my amps using an RCA to XLR adapter would be 22k.