John, I see in various photos and in the manual for the REF 5 that the following markings are present above the fuseholder:
5A Fuse
Slo-Blo
T3.15A (230)
I would interpret that to mean that you should use a 5 amp slow blow fuse, and that the reference to 3.15 amps would only apply if the preamp is wired for 230 volt operation, for use in a country having 230 volt (or similar) AC.
I don’t know either whether large or small is called for.
Best regards,
-- Al
5A Fuse
Slo-Blo
T3.15A (230)
I would interpret that to mean that you should use a 5 amp slow blow fuse, and that the reference to 3.15 amps would only apply if the preamp is wired for 230 volt operation, for use in a country having 230 volt (or similar) AC.
I don’t know either whether large or small is called for.
Best regards,
-- Al