M2TECH NASH, User Manual

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NASH
MC/MM PHONO PREAMPLIFIER
REVISION P
R
A – JUNE 2018
Copyright © 2018, M2Tech Srl
25
M2Tech
www.m2tech.biz
8. Trigger and power modes
The
NASH
accepts trigger signals, 5V
DC
to 15V
DC
. A trigger signal can be used to
automatically activate the
NASH
by a preamplifier, so that all the system is powered on and
off by the preamplifier’s remote control. To use the trigger input to switch the
NASH
on and
off, the trigger enable switch (Fig. 2, 13) must be set to “B” and the “power mode” must be
set to “Trigger in” by the menu.
As the
NASH
may be used in different setups and powered by either a simple wall adaptor
or by the Van Der Graaf MkII or any other main power supply, it is possible to choose how
it behaves when power is applied, as detailed in the table below:
Power mode switch Power mode setting Effect
A any
NASH
is off, push the front
panel button to activate
B disable
NASH
enters standby
B enable
NASH
activates immediately
B trigger in
NASH
enters standby and
trigger input is active
Of course, whenever the
NASH
is in standby it is possible to activate it by pushing the front
panel button (Fig.1, 1) or by sending an ON/OFF command by the IR remote control or by
the smartphone app.
The setting with the power switch mode in “B” and the power mode set to “enable” is very
useful when using the Van Der Graaf MkII or any other external power supply with on/off
switch to power the
NASH
.
9. Setting MC input resistance and gain
The
NASH
is provided with an internal MC preamplifier which allows for very low output
cartridges to be adequately amplified. A correct input resistance is overly important to
obtain the best performance by an MC cartridge. As this parameter is not standardized
amongst MC models, it’s important to have it adjustable. The
NASH
allows user to set the
input resistance to any value between 10 Ohms and 1000 Ohms by a pot on the back
panel (Fig. 2, 7).
As it happens with load resistance, every MC cartridge has its own output voltage, which is
not a standard value. Therefore, the MC preamplifier gain needs to be adjustable as well.
The
Nash
allows for setting the gain between 3dB and 30dB (that is, between 1.5x and
31x) by a rear panel pot (Fig.2, 5). The gain should be set so that the voltage out of the
MC preamplifier is around 5mV. An example: if your MC cartridge delivers 0.48mV, then
the MC preamplifier gain should be set to 10x, that is 20dB.