Manley REFERENCE PREAMPLIFIER - Manual (Page 8)

FRONT PANEL SPECIAL FUNCTIONS
THESE CONTROLS ARE NOT ON ALL MODELS. SOFT-START IS ONLY
AVAILABLE FOR 117 VOLT COUNTRIES. PHONO CONTROLS ARE ONLY ON
THE PHONO MODELS.
I - SOFT/START - This is only available on units wired for 117 volts. The SOFT/START (down)
mode is designed as a warm-up mode or a way to leave the pre-amp semi-powered so that it powers
up and stabilizes quicker. NORMAL mode is up and should always be used for listening. The SOFT-
START will certainly give much longer tube life than leaving the preamp powered in NORMAL. We
suggest that you turn the preamp off when not in use which reduces the electric bill and extends tube
life. Power it up in SOFT-START and give it 3 to 10 minutes in this mode, then up to NORMAL wait
30 seconds, then turn on the power amps. Do the reverse when shutting down. The tube filaments may
last decades this way. It is not a necessity but a way to achieve maximum tube life and stability.
J - MM / MC - You have to PULL the toggle towards you to switch. This switch is selected
depending on whether you use a moving magnet phono cartridge or a moving coil cartridge. This is a
special toggle to prevent "accidents".
K & L - 0 / 180 - These toggles allow you to reverse the polarity (phase) on each channel. "0" is the
normal position and both switches are usually switched in tandem. There are several applications of
these switches. A drum miked from the bottom, when struck will cause the skin to move towards the
mic and should cause the speaker (cone) to also move towards you. Unfortunately there are about a
hundred places in the recording/reproduction chain where this might have been reversed. For some
people and some systems the absolute polarity is a critical factor especially with reed instruments and
percussion. For most people it is a very subtle effect. You may find that a few albums sound more
natural in the 180 position. 2) It is possible to mis-connect the little connectors to the cartridge or mis-
wire the 5 pin XLR. The 0/180 switches allow you the easiest way to verify that your wiring is good.
If lows are reduced when only one switch is 180 then you probably got it right 3) Strange as it may
seem, quite a lot of people buy expensive systems and accidently reverse one speaker connection and
end up with a very wierd bass shy system. We have even seen (heard) this in audiophile trade shows.
Flip one of the toggles to see if Murphy's Law applies to you too. It should sound best with both
switches in the "0" position.
M & N - LEVEL TRIMS - Individual level adjustments for each channel to "fine tune" for variations
in cartridges, its mounting to the arm and slight mis-alignments of the arm. It also allows one to adjust
for slight drift in phono preamp gains as tubes age. After getting the BALANCE controls set using a
CD or other line source - Use a a few LPs to determine if any gain trim is needed in the phono
preamps. Adjust as needed. The easiest way is with a very "mono" LP and setting the phantom center
image exactly between the speakers.
One can also use these trims to adjust the phono stage to have a similar apparent level to the other
sources. This is becoming more difficult every year. The old standard was that -10 dBv was the
nominal reference level. Digital sources like CDs and CD players and DACs seem to avoid standards
and lean towards "the hotter, the better". Audio from video decks is a variable and remote controllable
and totally dependent on the tape or station (the wild card). Tape decks and tuners are still a pretty
good reference but there is always pressure to have the loudest station or hottest tape. Good luck.
8