4) Circuit Topology
REFERENCE
10
The tube electronics found in the Manley Reference Series
Microphones consist of two triodes per capsule in
cascade, forming an entire gain-block.
The tube employed in the Reference Gold and Reference
Cardioid is a dual-triode 12AX7 and the tube used in the
Reference Silver is a 5670 dual-triode. Both tube types are
easily obtainable and replaceable.
Removing the two Philips screws at the base of the
microphone body, allows the complete microphone
assembly to be removed so the tube may be replaced
easily, which is mounted in a ceramic socket with silver
pins. There is no need to remove the body from the
suspension system. Be wary not to touch the gold capsule
at the top of the assembly, this is very fragile, even a
finger-print on the diaphragm will impede performance.
The output of the tube stage is coupled through a custom
built Manley Iron output transformer of unparalleled
quality and substantial physical size employing pure
nickel laminations. The windings incorporate a bi-filar
winding technique which stops any possibility of
“humbucking”. The finished transformer is then resin
potted in a mu-metal enclosure maximizing stability.
