Palmer ADIG-ST User manual

MANUAL
PGA05
Palmer
Musical Instruments
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 not only accept the full power output of an amplifier, but also
a preamplifier or multieffect line output signal.

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.

Preamp/Multieffect Units and ADIG-ST
Using a shielded instrument cable, connect the stereo output of your preamp or multieffect unit to the
INPUT – CHANNEL 1 and INPUT – CHANNEL 2 sockets. The LINE/SPKS switch should be set to
LINE. To connect to the Microphone inputs of a PA or studio mixing desk, use balanced microphone
cables (XLR) from the XLR outputs BALANCED – CHANNEL 1 and BALANCED – CHANNEL 2. To
avoid overdriving the mixing desk inputs and reduce any signal noise, press the PAD 20dB switch.
This cushions the input signal by a factor of 10. If however the mixing desk already has a PAD-switch,
this should be used rather than the switch on the ADIG-ST.
Balanced microphone cables (XLR) should be used for all connections in order to cover long cable
distances without loss of signal quality. The BALANCED OUTPUT delivers a high enough line level
signal to directly drive a power amplifier.
Connecting several pieces of equipment together with differing chassis potentials can cause ground
loops resulting in a disturbing humming noise. There is a complete galvanic isolation between the
inputs and outputs of the ADIG-ST, nevertheless the LIFT/GND switch allows a further protection
against this happening.
The UNBALANCED OUTPUTS may be used as a line-out to connect to a monitor amplifier, or to the
sound card of a computer for HD recording.
Guitar Amplifier and ADIG-ST
Your guitar amplifier may have a line-out socket, which you should connect as above.
Normally however, the amplified sound is shaped not only using the tone controls, but also overdriving
the amplifier. In this case the ADIG-ST should be hooked up between amplifier and loudspeaker.
Connect a loudspeaker cable (NOT an instrument cable) from the speaker output of the amplifier to
the INPUT of the ADIG-ST. The switch beside the input socket should now be set to SPKS. A tube
amplifier must only be operated with an output load resistance. This means a loudspeaker box must
be hooked up to the THRU jack. If you don’t want a loudspeaker then use a Loadbox (dummy load).
NEVER operate a tube amplifier without some sort of Loadbox, as this will lead to massive and
permanent damage to the amplifier. We cannot be held responsible for any damage caused by faulty
wiring or ignoring this warning!
Check all wiring and connections before switching on!
If the amplifier has a separate, parallel loudspeaker output, this can be directly hooked up to the
INPUT of the ADIG-ST using a loudspeaker cable. The amplifier loudspeaker should be left connected
as usual, with the output impedance switch set to the appropriate value for the loudspeaker (4/8/16
Ohm). The input impedance of the ADIG-ST is so high that it will in no way influence the normal
amplified sound.
Tip! If you are not using both channels of the ADIG-ST, link the THRU - CHANNEL 1 socket to the
INPUT - CHANNEL 2, then you can use the controls of both channels to optimize the separate “clean”
and distorted sounds. Feeding the two outputs through a Switching System/ Looper allows you to
alternate between the two different sounds.
Switches and Controls
After everything is connected together, switch each piece of equipment on, leaving the ADIG-ST till
last. All faders on the mixing desk should be turned down. This applies to all equipment connected to
the outputs of the ADIG-ST, as extreme switching noise eventually causes loudspeaker damage.
Configure your Preamp/Multieffect unit or amplifier to your normal sound settings.
If your preamplifier has an output switching choice of –10db or 0/+6dB, then use the 0/+6dB position,
otherwise set the preamp output control (Master Volume) approximately in the middle position. The
usual start settings on the ADIG-ST are as follows: FULL RANGE: completely off (counter clockwise
position),
VOICING: LOW and HIGH in the middle position,
COLOUR: switch depressed to LITE. Now turn the FILTER VOLUME control up until the mixer desk
input (using PFL/SOLO switch) has an adequate level.

Turning the HIGH control gives you a sound between MELLOW soft, to aggressive BRIGHT.
We cannot start to name all the different makes of amplifier/speaker combinations, but the average,
experienced musician will know the terms British/California sound categories of speaker boxes. The
LOW control decides the type of Speaker box that can be emulated. FLAT describes more the “Thin”
sound of a 2 X 10”cabinet, while the other extreme DEEP represents a double 4 X 12”stack. Between
these settings lie a multitude of other possibilities to find your preferred speaker/sound combination.
The COLOUR switch decides the Character of the loudspeaker. BROWN is a darker almost nasal
sound, while LITE an opener, full range sound. The COLOUR-switch is strongly influenced by the
position of the of the HIGH control.
If you prefer aggressive distorted sounds, mix in the FULL RANGE VOLUME control, but it is essential
to press the HI-CUT switch to avoid the notorious “Paper Cutting”sound. For extra-clean sounds
however, we do recommend using the FULL RANGE without the HI-CUT function.
We have deliberately only given basic suggestions, and no sure recipes. We are confident that
professional musicians will soon find there own individual sound.
ADIG-ST Specifications
Special two channel DI-box, with loudspeaker-simulation filters.
Casing: 19”1U Rack, 170mm deep
Each Channel
Input: Unbalanced jack
Parallel Output (Thru): Unbalanced jack
Input Level: Switchable between Instrument- and Loudspeaker, ground-free
Output: 1 x XLR/m transformer balanced, with Microphone/Line PAD switch
2 x unbalanced jacks, floating ground
Controls: Volume Filter, Low, High, Full Range Volume
Switches: Brown/Mellow, 6kHz Hi-Cut
Ground Lift Switch: Ground, Lift
Power Supply: 115/230V Switchable, Fuse 63AT/230v, 125mAT/115V
On/Off Switch, LED, Combined Power Socket/Fuse Holder
© Palmer Musical Instruments, Adam Hall GmbH, D-61267 Neu-Anspach, Daimlerstr. 9, Germany TEL: ++49 (0)6081 94190
FAX:++49 (0)6081 94190 Web: www.palmer-germany.com, e mail: [email protected]
USA: JAMS audio, 4605 Elkins Avenue, Nashville, TN 37209, www.palmergear.com, e-mail: [email protected]
Call Us: 615-383-JAMS(5267), Fax Us: Toll Free 866-381-JAMS(5267)