It’s probably not possible to predict with any kind of certainty what if any sonic downsides might result from doing that. In part because one of the key factors that is involved, the output impedance of the AV8802A, does not appear to be specified. And in part because the input impedance of the RX-7 is indicated as "minimum 10K ohms," which is rather low, and using a splitter to have a single output of the AV8802A drive two RX-7 inputs would result in the AV8802A seeing a load impedance equal to half of that value. And a load impedance of 5K is low enough to result in some degree of sonic compromise when driven by **some** preamps, AVRs, or other line-level components.
FWIW, though, given that the AV8802A is a solid state component, and therefore **probably** has an output impedance that is reasonably low, my guess is that there is a good chance it would work out ok.
Also, rather than using an Audioquest splitter cable, you might want to consider using one of these relatively inexpensive balanced y-cables, that are typically used in pro audio applications.
Regards,
-- Al
FWIW, though, given that the AV8802A is a solid state component, and therefore **probably** has an output impedance that is reasonably low, my guess is that there is a good chance it would work out ok.
Also, rather than using an Audioquest splitter cable, you might want to consider using one of these relatively inexpensive balanced y-cables, that are typically used in pro audio applications.
Regards,
-- Al