4
Overview
M1400 and M1400i power amps built after June 15, 1999 have some rather lovely
improvements. These include:
1.
Higher output fan for increased cooling
– The old fan which has an output of 51 CFM has
been replaced with a new hi-performance Panasonic FBA0824H1T fan that has 62 CFM
output. This improves the M1400/1400i’s cooling capacity by 20%, allowing them to run in
an environment 14°F hotter than previously without overheating.
2.
Higher voltage tolerance
– the four main filter capacitors have been increased in
voltage rating from 80V to 82V. This improves the ability of the M1400/1400i to handle
installations and gigs where the AC line voltage is higher than normal.
3.
Improved speaker protection circuitry
– Previously, under certain unusual conditions,
(such as the SeaHawks winning an away game), the protection circuits could shut down
the amplifier. The circuit is redesigned so instead of shutting down, the amplifier will
mute for two seconds and then begin operation again.
4.
Other improvements
– The new designs have improved reliability by changing the design
surrounding the driver transistors, specifying higher quality main 30A bridges, removing all
soldered-in multi-pin cable assemblies in favor of more reliable (and more expensive)
header to receptacle interconnections, increasing the robustness of the +/-16V power
supplies, and redesigning the baker clamp for improved high power operation.
5.
New circuit boards
– The new designs have new circuit boards.
6.
Handles Removed
– The new designs have no handles on the front panel. This is also a
quick way of telling if the amplifier is a series II design or not.
7.
Service Manual
– The old service manual contains many details which still apply, such as
circuit theory and troubleshooting. This series II manual is just a basic guide to the new
schematics, pcbs, assembly drawings and parts lists.
8.
Owner’s Manual
– The owner’s manual was only mildly altered to reflect the new model,
so all details of the amplifier’s operation are correct.
9.
Service bulletin
– The ribbon modification still applies to the “series II” models. See the last
page of this service manual.
