On my Mastr I I (station) I connected directly to VOL/SQL HI on the system shelf backplane. No pads,  nor external shaping networks. <br>
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Using the DSP for everything.  <br>
Works great. <br>
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Even have had compliments on the received audio. <br>
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And Bryan, yep, our station also uses +4 as reference.  As you say, pretty much standard practice. <br>
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Sent from my Android phone with K-9 Mail. <br>
Please excuse my brevity and typing errors.