6
UM TG12345CB-123121
OPERATION
Nomenclature
You will notice white and gold markings on the controls of
the front panel; this is by design.
Because of the new controls and settings added to the
TG12345 Curve Bender, we have used two colors for control
settings. White labels designate a setting exactly as it would
have been on a vintage TG unit, gold designates selections
chosen by Chandler Limited’s Chief Designer, Wade Goeke.
This way you may accurately recall a standard TG setting or
purposely break all the rules.
Bypass
Each channel “IN LEFT” and “IN RIGHT” of the TG12345
Curve Bender may be fully bypassed by use of these push-
buttons. Their main use is for direct comparison of processed
and unprocessed sound.
When depressed, the button’s LED will illuminate bright
blue, signifying the EQ channel is active.
Conversely, when the button is not depressed, button’s LED
will not be illuminated, and the EQ channel is bypassed.
This bypass functionality is ‘true bypass’, i.e. the TG12345
Curve Bender is completely removed from the signal path.
Note:
Very early Chandler Limited TG12345 Curve Bender
EQs were not ‘true bypass’.
Output Gain Control
The Left/Right master output channel gain controls feature
stepped hand-wired gold contact switches for audiophile
quality.
The master output channel gain switches are labeled for +/-
5db and adjustable in .5db steps, and are used for adjusting
unity gain through the unit as you apply equalization.
Revision Note:
Prior to 2011, standard version TG12345
Curve Benders fe/-10db output controls, in 1db
steps.
Historical Note:
The TG12345 MK.I amplifier was used in
the following TG consoles:
MK.I - was the original prototype desk used to record the
Beatles Abbey Road album; only one of these was ever pro-
duced.
MK.II - Three of these were built for deployment in studios
1, 2, 3 at Abbey Road Studios and a fourth for the mobile
recording section. These desks were used to record John
Lennon’s “Instant Karma,” Paul McCartney’s “Maybe I’m
Amazed” and George Harrison’s “All Things Must Pass” sin-
gles and albums respectively.
MK.III - The TG12345 MK.I amplifier was also used in the
MK.III desk.
The TG12345 MK.IV desk was the huge wrap-around TG
desk used to record Pink Floyd’s “Dark Side of the Moon,”
and was the first implementation of the TG MK.IV silicon
based amplifier. The MK.IV amp is prevalent in much of the
Chandler Limited, EMI/Abbey Road Studios reissues.
Initially, MK.IV desks were fitted with MK.II and MK.III cas-
settes, however, were upgraded to MK.IVs. Once upgraded
and having quadraphonic capabilities, these TG MK.IV desks
were also known as ‘Mark.Q’.
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BASS
PRESENCE 2
PRESENCE 1
TREBLE
35
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91
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OUT
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OUT
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OUT
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OUT
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OUTPUT
OUTPUT
IN LEFT
IN RIGHT
OUT
X 1
X 1.5
OUT
X 1
X 1.5
OUT
X 1
X 1.5
OUT
X 1
X 1.5
OUT
X 1
X 1.5
OUT
X 1
X 1.5
OUT
X 1
X 1.5
OUT
X 1
X 1.5
kHz
kHz
kHz
Hz
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70
91
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OUT
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2.8
OUT
3.6
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1.2
1.8
2.8
3.6
4.2
6.5
OUT
8.1
3.6
4.2
6.5
8.1
10
12
16
OUT
20
12345
BASS
PRESENCE 2
PRESENCE 1
TREBLE
kHz
kHz
kHz
Hz
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BASS
PRESENCE 2
PRESENCE 1
TREBLE
35
50
70
91
150
200
300
OUT
.3
.4
.5
.8
1.2
1.8
2.8
OUT
3.6
.8
1.2
1.8
2.8
3.6
4.2
6.5
OUT
8.1
3.6
4.2
6.5
8.1
10
12
16
OUT
20
OUTPUT
OUTPUT
IN LEFT
IN RIGHT
OUT
X 1
X 1.5
OUT
X 1
X 1.5
OUT
X 1
X 1.5
OUT
X 1
X 1.5
OUT
X 1
X 1.5
OUT
X 1
X 1.5
OUT
X 1
X 1.5
OUT
X 1
X 1.5
kHz
kHz
kHz
Hz
35
50
70
91
150
200
300
OUT
.3
.4
.5
.8
1.2
1.8
2.8
OUT
3.6
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1.2
1.8
2.8
3.6
4.2
6.5
OUT
8.1
3.6
4.2
6.5
8.1
10
12
16
OUT
20
12345
BASS
PRESENCE 2
PRESENCE 1
TREBLE
kHz
kHz
kHz
Hz
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