Fsmithjack, in general adapters may or may not work ok depending on the specific designs of the components that are being connected. In this case the comments made earlier in the thread by Tim (Mitch2) indicate that they will NOT work ok. But note his suggestion of a Jensen transformer, which can convert a single-ended signal to a true balanced signal pair. Their model PI-RX (similar to the PI-XX shown
here except with RCA input connectors), can and should be placed very close to the amp. You could then use a very short length of XLR cable.
Nearly all interconnect cable effects are proportional to length. Therefore the short length of the XLR cable would reduce its importance, increasing the likelihood that choosing an expensive cable will be unnecessary. And of course the short length will in itself reduce the cost of the cable.
I note that the Jensen site does not specifically list a PI-RX configuration, having an RCA input connector and an XLR output connector, but I'm pretty certain they can supply that configuration on special order. It would cost a bit more than $300 for the two transformers you would require.
Good luck. Regards,
-- Al
