Does your REL have dual low level inputs or single?
If dual, your best option is to use the dual RCA low level output form your pre.
see the last video on this page:
connecting Benchmark preamp to REL via high level?
Hey All,
I have a desktop setup using a Benchmark preamp to powered speakers
The preamp has a mono balanced output (as well as dual left right outputs)
Is it possible to use this mono output towards the REL high level input?
If so, would this be beneficial over sending it to the REL low level in any way?