Manley HIGH FREQUENCY (DE-ESS) LIMITER - Manual (Page 6)

OPERATIONAL NOTES
SWITCHING ON
The power switch is located on the right hand corner of the front panel. Flip the switch up to turn
on the unit and down to turn off the unit. Do not switch on and off rapidly in succession.
TUBE LIFE
As with all tubes, their quality degrades with age. This is due to cathode emission, a natural
process found in all tubes. Excessive increase in noise (hiss) can indicate the need to replace a
tube. Usually, the 12AU7A will be the one to try first as this is the tube in the gain stage. The
6414 is the output tube. Microphonics are a natural occurrence found to some extent in all tubes.
We try our best to select the least microphonic tubes possible.
TUBE SUBSTITUTION
This circuit has been optimised around the 12AU7WA and the military 6414 tube types. We also
believe these are the best tubes for your unit. Replacement tubes can be obtained from Manley
Laboratories. However, if you're stuck in a pinch, the following tubes are approved substitutes for
this unit:
For the 12AU7WA: 5814, ECC82 (exact substitutes)
For the 6414: 12AT7, ECC81, 12BH7A (not exact substitutes, but they will work fine with a little
less current output)
CUSTOM VERSIONS
For mastering use, we also build a custom version of the Manley High Frequency Limiter which
has stepped controls (rotary switches) replacing all front panel pots.
.
6414
output tube
12AU7WA
input tube
SIDECHAIN
SECTION
POWER
TRANSFORMER
MIT Multicap
output capacitor
Gain make-up
amplifier