Hello. I'm looking at either buying a MSB Reference or Select II. I've read through some of the great posts here on the DACs but I don't believe I saw anyone discuss subwoofer output when using either DAC as also a Preamp. Do any of you have the optional Isolated Subwoofer Analog Expansion Module? If so, could you provide some thoughts on it's performance. I also see that there is another option called the Sub Isolator https://www.msbtechnology.com/dacs/sub-isolator/, which looks like a dongle that connects to one of the output XLRs. Do any of you have experience with this? Thanks.