Palmer ADIG-ST
(Order No: PGA05)
Warning!
The ADIG-ST does not contain a Load Box. When used with a tube
amplifier, there must be a load connected to the amplifier output. See
section - Guitar Amplifier and ADIG-ST.
Background
The ADIG-St is one of a special series devoted to the direct injection of guitar amplification. A DI box
should normally transfer a linear signal through its circuitry.
The guitar amplifier’s loudspeaker, however plays a very important role in forming the electrified
sound, and therefore must be taken into account when replacing the miked-up sound. While the ADIG-
LB has a built-in Load Box (loudspeaker substitute) for connecting directly to the amplifier, the ADIG-
ST differs in that it is effectively a two channel (stereo) DI box. This means that it can accept the full
power output of an amplifier, or a preamplifier/multieffect line output signal.
Most digital multieffect units have a built-in “Recording Output”, which is declared to “accurately”
reproduce the Microphone/Loudspeaker-Combination. After the initial euphoria has died down, the
experienced musician realises that all of these sounds are flat, lacking in power and rapidly become
very boring. This will not be the case using the “faulty” analogue technology of the ADIG-ST. Due to
the imperfect filtering, the subtle phase changes and conflicts that a normal loudspeaker generate,
will produce a more lively and diversified sound.
Concept
As stated, the ADIG-ST has two completely separate channels which can be individually adjusted for
sound and tone. This is ideal for a stereo DI guitar set-up.
In each channel, the input signal is powered up using a very small built-in amplifier.
The mini-amplifier has an operating voltage of about 60V and therefore guarantees an excellent
dynamic sound. This signal is then led through the LC-filters which form the loudspeaker “sound”. The
thus-formed signal is then fed through a transformer-isolated line-out stage to give a ground-free
balanced XLR output, or unbalanced jack output. Parallel to this, a second signal that we’ll call a “Full
range signal” is also fed to the final stage. Without using up a second channel on the mixing desk,
these two signals can be mixed using the “Full Range” volume control. Very often this technique is
used in the recording studios when a direct (clean) signal is mixed with the loudspeaker output to
create a “cutting” bright sound. The extreme highs can be filtered out to give a smoother sound by
using the 6kHz Hi-Cut-Filter. This method can be used to reproduce the sound of a 12” loudspeaker,
and also the slightly higher pitched 10” loudspeaker.
Connections and Set-up.
The ADIG-ST is not only useful in the studio, but also for live performances, so here are a few
common set-ups. Please check the voltage requirement in your area and adjust the voltage switch
accordingly. The two position switch can be found on the base plate under the Palmer sign. If your
local power supply is 100 – 120 Volts, the switch should read 115. In Europe and many other
countries, the power supply is between 220 and 240 Volts, and should be set to 230.
All in- and outputs are on the back panel, all adjustment controls for sound shaping are on the front. If
the voltage switch is correctly set, use the supplied power cable to connect the mains supply, but do
not switch on just yet.
