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SMX RANGE
O P E R A T I N G INSTRUCTIONS

Congratulations on purchasing your Trace Elliot Sound Management Series amplifier/speaker set up.

With your purchase you should have received a separate Owner's Warranty Registration Form plus mains cable (except in the case of speaker cabinets). If you did not receive these items please refer to the dealer who sold you the equipment.

Using this manual
Although Trace Elliot Sound Management Series equipment represents the ultimate bass amplification technology, it is also designed to be user-friendly straight out of the box. However, careful consideration to the relevant information contained in this booklet will provide you with the necessary benefits to really get the best out of your equipment. Reading the Quick Set-up instructions will provide you with basic information if you have just got your equipment home and are keen to start using it. However, please find time to read the full instructions to fully understand its functions and capabilities. Please also observe the safety instructions at the end of this manual.

GP12SMX OPERATING INSTRUCTIONS Getting Started - A quick guide
As well as being available in its stand alone rack-mounting format, the GP12SMX Sound Management Series preamp is included in the following products:-

Amp heads: AH600SMX, RAH600SMX, AH400SMX, RAH400SMX, AH300SMX, RAH300SMX, Combos: 1210HSMX, 1210SMX, 1215SMX, 122HSMX, 122SMX
Therefore, careful attention should be paid to this section if you own one of these units. This QUICK GUIDE is for those that have used TRACE ELLIOT equipment before and are familiar with using the INPUT GAIN control and GRAPHIC sections. With mains power connected to the GP12SMX, and the voltage selector set to the correct voltage for your country, turn on the power to the unit with the rear panel switch. If all is well the front panel will illuminate and assuming that you are correctly connected to power amp and speakers the GP12SMX will be ready to use. N.B. The GP12SMX should always be turned on and off with the front panel switch set to STANDBY. This will ensure that the unit powers up and down silently. With the controls set as in diagram 1 the GP12SMX is set completely FLAT,i.e. no EQ is applied to the signal. The signal remains exactly as it came from the instrument. This is always a good place to start, by first becoming familiar with the pure sound of your instrument you will be better able to decide what sound modifications will give you the results you require.

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Basic sound
Although the familiar basic sound of a TRACE ELLIOT preamp has been retained in the GP12SMX, you will also find an additional pallet of sounds readily available that cover many styles of bass playing. Most of these are available without the need for you to alter your favourite GRAPHIC setting.

Input blend
The INPUT BLEND control allows you to select the signal to drive the rest of the preamp from two entirely separate FRONT END circuits. One being a SOLID STATE circuit using an FET to provide a very high impedance input, the other being a VALVE stage, also providing a high impedance but in addition adding that something extra that only a valve can. Any mix of these two input stages can be selected using the INPUT BLEND control.

Pre shape
As well as the well known classic TRACE ELLIOT PRE SHAPE (SHAPE 1), a second fixed EQ has been added in the form of SHAPE 2. This is a more ROCK orientated PRE SHAPE with solid bottom end and more mid than SHAPE 1.

Altering the EQ
The GRAPHIC EQUALISATION section in this unit is based on the traditional TRACE ELLIOT 12 band design, and apart from minor improvements that have been made in the `Q' or bandwidth at certain frequencies, this will perform exactly as the SERIES 6 units. The setting of this will therefore be familiar to those reading this QUICK GUIDE. In place of the GRAPHIC BALANCE slider used in previous designs, we now have a simple GRAPHIC LEVEL control. This adjusts the level of the GRAPHIC section when selected by the front panel push switch or the foot switch, and should be set to give approximately the same overall level with the graphic either in or out.

EQ balance control
This is something very new in concept, and something that you will not be familiar with from any amplifier. As such it requires a short description of its function (a full description is given in the SOUND MANAGEMENT section later in these instructions). Basically it is a very powerful new kind of tone control section on one knob. It can be thought of as a pivot point at the centre of the graphic about which the frequency response of the graphic may be swung. Turning to the right increases the top end and decreases the lower end of the graphic, whilst turning to the left has the reverse effect. You do not need to understand exactly how this is done to appreciate the power it gives you in instantly being able to transform your sound with one simple to operate knob.

Compression
TRACE ELLIOT have always avoided including compression in any of their previous amplifiers as the integrity of the bass signal has always been paramount in all designs. The reason for this is simply that any kind of FULL RANGE compression used on bass is always an unacceptable compromise. It cannot act fast enough to catch attack transients, and if it does then it distorts low frequency signals. If you have used any full range compression then you know what we mean. The compression used in this unit has therefore been split into two entirely separate compressors, one optimised for LOW frequencies and one optimised for HIGH frequencies, but both individually adjustable by the user. The LOW COMPRESSION and the HIGH COMPRESSION controls are located either side of the EQ BALANCE control. These three controls together we refer to as the SOUND MANAGEMENT section of the GP12SMX, as they work as a unit and provide such a vast variation to the bass sound. As a QUICK GUIDE we would advise that full compression on either LOW or HIGH is never necessary except purely as an effect. LOW compression used on its own and set up to about halfway will really tighten up the bottom end and give excellent definition to bass runs. LOW compression past halfway with the EQ BALANCE turned a quarter left is excellent for really low reggae type bass. A small amount of both HIGH and LOW is good for those middly pumping bass lines. The best way is to experiment bearing in mind that HIGH compression is very rarely needed as you will lose attack dynamics, and if your bass is active you will probably also emphasise the hiss coming from the instrument as well.

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REAR PANEL FACILITIES Line outputs
FULL RANGE STEREO line outputs are provided as well as the crossover STEREO HIGH PASS and LOW PASS line outputs.

Crossover
A stereo crossover with variable crossover frequency is built into the GP12SMX to provide BI-AMPING facilities. The HIGH PASS section is in stereo whilst the LOW PASS section is in mono.

D.I.
Three D.I. sockets are provided with all three being balanced outputs giving levels of signal to suit the LOW IMPEDANCE MICROPHONE inputs on a mixing desk. All three have GROUND LIFT facility for use on balanced inputs to eliminate any ground loops. The PRE EQ D.I. is fed from before the GRAPHIC but after the PRE SHAPE, whilst the stereo POST EQ D.I.'s are after all EQ COMPRESSION and EFFECTS returns but prior to the output level control.

Ground lift
A GROUND LIFT switch is provided to lift the mains ground from the signal circuits and prevent a ground loop being formed between the pre amp and the power amp.

GP12SMX Pre amp full instructions
The following is a more detailed description of the facilities of the GP12SMX pre amp.

Input
There is only one instrument input jack provided, this will perfectly match both passive bass guitars (i.e. those with no internal battery) and active instruments by selecting either type with the switch adjacent to this socket.

Input gain setting
To get the best results from your GP12SMX it is important to understand fully the correct use of the INPUT GAIN control and the stage OUTPUT LEVEL control. The optimum setting is achieved when the INPUT GAIN control is as high as possible without lighting the red OVERLOAD LED. The stage OUTPUT LEVEL should always be set as low as possible to achieve the required volume i.e. the INPUT GAIN is adjusted and left set at the optimum level while the OUTPUT LEVEL is used to make any changes to the amplifier volume. To set these two controls correctly use the following procedure:1. First turn the OUTPUT LEVEL control to zero. 2. Plug your bass in and select ACTIVE or PASSIVE to suit the instrument 3. Turn all volume controls on your bass up full. 4. Gradually turn up the INPUT GAIN control while playing your bass as hard as you are likely to during your performance. 5. When the red OVERLOAD LED lights up reduce the INPUT GAIN slightly until this LED goes out. 6. Now turn up the OUTPUT LEVEL to give the desired volume. N.B. For most basses the INPUT GAIN control will end up being set between 5 and 8 on the scale

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Please note: If the GRAPHIC EQUALISATION is altered it may be necessary to re-adjust the INPUT GAIN control. Re set the INPUT GAIN by following steps 3 to 6 in the above procedure. Remember during normal playing the yellow OK LED should light up, with the red OVERLOAD LED only occasionally flicking on for heavier pulls or slaps. Playing PASSIVE basses with the instrument volume control turned back will reduce the upper frequency response of the instrument so try to keep this control well advanced, using the preamp OUTPUT LEVEL control to provide for larger changes in volume.

Input blend control
The input section to this preamp is very different to all previous Mk5 and Series 6 units. It has two separate input circuits, one valve and one solid state. Both of these have a very high input impedance, which perfectly matches the output impedance of PASSIVE basses. The INPUT BLEND control provides a continuously variable mix of the output from these two input stages i.e. you can have an all SOLID STATE input by turning this control fully anticlockwise, or an all VALVE input by turning the control fully clockwise, or any mix of the two.

Pre shape
The PRE SHAPE facility is like a preset graphic equaliser built into the GP12SMX that you can switch in or out to modify the sound of the bass. Two pre shape sounds have been provided on this unit and are selectable from the front panel. The selected shape may be switched in or out via either the front panel switch or the external foot switch. PRE SHAPE 1 is the classic TRACE ELLIOT EQ as found on Series 6 units, it adds a boost at both the low end (50Hz) and the high end (2 to 5kHz) of the frequency spectrum as well as a cut at mid frequencies (400Hz). PRE SHAPE 2 is a more rock orientated equalisation providing a wider bandwidth boost at low frequencies, less of a mid cut and a slight boost at higher frequencies. This is a less extreme EQ than PRE SHAPE 1. Both these pre shaped sounds will add extra punch to your sound and may be used with or without the GRAPHIC EQUALISATION section being switched in.

Using the graphic equaliser
Below is a representation of the graphic sliders showing the frequency centres and degrees of BOOST and CUT available with them.
EXTREME BOOST NORMAL MAXIMUM BOOST MEDIUM BOOST SLIGHT BOOST NO EFFECT SLIGHT CUT MEDIUM CUT NORMAL MAXIMUM CUT EXTREME CUT

+15 +10 +6 +3 0 dB -3 -6 -10 -15 30 Hz 40 Hz 60 Hz 100 Hz 180 Hz 340 Hz 660 Hz 1.3 KHz 2.6 KHz 5 KHz 10 KHz 15 KHz

+15 +10 +6 +3 0dB -3 -6 -10 -15

A carefully designed GRAPHIC EQUALISER is a flexible way of varying the sound of a bass guitar and if properly used will provide an extremely powerful method of tone shaping for your instrument. The GP12SMX has a 12 band GRAPHIC EQUALISER that can be switched IN or OUT of the signal path from the front panel push button or from the external footswitch. Because of the flexibility and massive BOOST and CUT potential of the GRAPHIC it is important to know ho to get the best from it.

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It is equally important to know how to avoid the problems that can be associated with its incorrect use, so firstly here is a list of things not to do, and why:1. Do not fully boost just one frequency band as this will tend to emphasise a small range of notes on the bass producing a PEAKY and not very useful sound. 2. Do not boost or cut all frequencies as this will have the same effect as increasing or decreasing the overall volume level without affecting the tonal characteristics of the sound. 3. Do not use excessive bottom (30 or 40Hz) boost on the graphic unless your speakers can handle it (very few speaker systems are capable of handling frequencies as low as this with any degree of efficiency). N.B. Boosting at 30Hz for instance will not add to the perceived amount of bottom end in the sound, it will only make your speakers flap to no useful effect. In fact boosting at 100Hz or 180Hz will have the apparent effect of adding far more BOTTOM END than boosting at 30, 40 or even 60Hz. 4. Do not use excessive top (10 to 15kHz) boost, this will tend to add mostly HISS to the sound as there is very little signal output at this frequency from a bass. The 12 sliders have been provided to give you full control at all frequencies providing a flexible and comprehensive bass EQ system for the discerning user. The 30Hz slider has been provided to allow precise tailoring at very low frequencies when using a 5 string bass where the low B string is around 30Hz, and even then it is a case of how much 30Hz to CUT rather than BOOST to get the speaker system working at its optimum efficiency.

Useful observations
The fundamental frequency range of a bass guitar is from 41.2Hz (bottom E string) to around 392Hz (two octaves up on the G string) not a very wide range. Obviously a lot of harmonics are produced when playing and these can extend up to 5kHz or more. Other frequencies are also produced by the attack portion of the note When the string is first struck. This attack can be emphasised by boosting the top end. However because of the fairly small range of frequencies from the bass by top end we mean between 1.3kHz and 5kHz. You will find by boosting at 5kHz the ATTACK will be emphasised whereas by boosting at 1.3 and 2.6kHz you will bring out the harmonics in the note. Above this frequency range you will find it is better to use a small degree of CUT to reduce any HISS present as this will not be masked by the bass signal when playing, due to the very small amount of bass frequency content at 10 to 15kHz. Use the 30Hz and 40Hz sliders sparingly unless you have a massive stack of speakers available, and the power amps to drive them. You will find that rolling off the bottom end by using these two sliders to give a degree of cut will allow you to play at a far greater volume level without the speakers complaining.

Back to the graphic
Having got out of the way the things NOT TO DO we move on to what you can do with the GRAPHIC EQUALISATION section. Basically you can do whatever you like as long as you bear in mind the DONT'S and follow two simple rules, these are:1. Try to keep the slider settings balanced around the 0dB line on the graphic.(see the diagram opposite) 2. Try to set the sliders in a smooth, gentle curve, as setting adjacent sliders at opposite extremes will give sharp [peaks and troughs in the sound, emphasising some notes and killing others. (see diagram opposite) Switch the graphic IN and experiment with the available sounds but remember TOP END means 1.3kHz to 5kHz, BOTTOM END means 60Hz to 180Hz and MID RANGE means 340Hz and 660Hz. N.B. Don't forget to re-adjust the INPUT GAIN setting once you have altered the graphic. This is necessary because altering the graphic will change the overall gain and the level indicating circuit monitors the signal at a number of places to ensure that clipping or distortion is not occurring at any stage. Consequently changing the gain will change the reading on the LED's and you will have to re-adjust the INPUT GAIN control to compensate.

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+15 +10 +6 +3 0 dB -3 -6 -10 -15 30 Hz 40 Hz 60 Hz 100 Hz 180 Hz 340 Hz 660 Hz 1.3 KHz 2.6 KHz 5 KHz 10 KHz 15 KHz

+15 +10 +6 +3 0dB -3 -6 -10 -15

+15 +10 +6 +3 0 dB -3 -6 -10 -15 30 Hz 40 Hz 60 Hz 100 Hz 180 Hz 340 Hz 660 Hz 1.3 KHz 2.6 KHz 5 KHz 10 KHz 15 KHz

+15 +10 +6 +3 0dB -3 -6 -10 -15

RIGHT - BALANCED AROUND 0dB

WRONG - SLIDERS NOT BALANCED AROUND 0dB

+15 +10 +6 +3 0 dB -3 -6 -10 -15 30 Hz 40 Hz 60 Hz 100 Hz 180 Hz 340 Hz 660 Hz 1.3 KHz 2.6 KHz 5 KHz 10 KHz 15 KHz

+15 +10 +6 +3 0dB -3 -6 -10 -15

+15 +10 +6 +3 0 dB -3 -6 -10 -15 30 Hz 40 Hz 60 Hz 100 Hz 180 Hz 340 Hz 660 Hz 1.3 KHz 2.6 KHz 5 KHz 10 KHz 15 KHz

+15 +10 +6 +3 0dB -3 -6 -10 -15

RIGHT - SMOOTH CHANGES

WRONG - CHANGES TOO ABRUPT

Graphic level control
The GRAPHIC LEVEL control adjusts the level of signal from the graphic section only. Consequently it will have no effect when the graphic is switched out. This control is to allow you to balance the levels between graphic IN and graphic OUT, and should be set so that only a change in EQ occurs when the graphic is switched in and not a large change in level as well. It can however be used to provide a boost in level when the graphic is switched IN if desired although we would advise that this is kept to a small increase so as not to overload the following stages.

Sound management section
This section includes the EQ BALANCE control and the HIGH and LOW COMPRESSION controls as shown below:Firstly a short explanation is required about this section as it is an entirely new concept in terms of a means of EQ adjustment. The signal entering this section is a full range mono signal, this is then split into two with one part containing the HIGH PASS (upper frequency) content of the signal and the other part containing the LOW PASS (lower frequency) content of the signal. Both parts pass through their own separate compression circuitry and then on to the EQ BALANCE control. Here they are re-combined into a single full range signal once again that contains a mix of the HIGH and LOW frequencies in proportion to the setting of the EQ BALANCE control.

EQ balance
As can be seen from the diagram of this section the EQ BALANCE control varies between HIGH, LOW and is FLAT in its centre position. The action of this control can be envisaged by imagining a pivot point at the centre of the graphic about which the frequency response of the graphic can be swung. Turning the EQ BALANCE control to the right increases the top end and decreases the bottom end of the graphic, while turning it to the left decreases the top end and increases the bottom end. The internal filter circuits that feed this control have been designed to allow the HIGH PASS and LOW LOW PASS signals to overlap in frequency so that fully LOW or fully HIGH may be used as individually useful sounds in their own right i.e. with the EQ BALANCE control set at a fully LOW PASS there is still enough higher frequency content in the sound to make it useful. The opposite being true when the EQ BALANCE control is set fully HIGH PASS.

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N.B. Do not confuse these HIGH and LOW PASS circuits with those of the output crossover circuitry, they are entirely separate parts of the circuit and do not interact in any way. Remember the HIGH and LOW PASS signals within the SOUND MANAGEMENT section of the unit are re-combined into a single full range signal at the EQ BALANCE control. Whether or not you understand its action, you will find the EQ BALANCE control a very easy and flexible way to instantly modify your sound over a wide range.

Compression
TRACE ELLIOT have always avoided including compression in any of their previous amplifiers as the integrity of the bass signal has always been paramount in all designs. The reason for this is simply that any kind of FULL RANGE compression used on bass is always an unacceptable compromise. It cannot act fast enough to catch attack transients, and if it does then it distorts low frequency signal. If you have used any full range compression then you know what we mean. The compression within the GP12SMX has therefore been split into two entirely separate compressor, one optimised for LOW frequencies and one optimised for HIGH frequencies, but both individually adjustable by the user. Separate attack and release characteristics are used for the HIGH and LOW compression, fast for the HIGH and medium to slow for the LOW. Fast is needed on the HIGH compression in order to catch initial high frequency transients on striking the string, if however this speed of attack is used for the LOW compression it produces distortion on low bass notes. If the slower attack is used on the high frequencies any initial transient will get through unchecked and subsequent transients will disappear as the low bass compression would not have had time to recover, i.e. the release is too slow for the high frequencies.

Low compression
The LOW frequency compressor acts upon the low pass signal within the SOUND MANAGEMENT section. Applying the compression to the LOW PASS only gives a fat bottom end to the sound without losing the upper frequency attack characteristics of the note. It is somewhat of a less processed sounding effect than full range compression but works extremely well in smoothing out bass signal peaks allowing a far greater volume of amplification to be used without the risk of speakers flapping. You will also find that a degree of LOW compression will add definition to your playing, bringing out the notes within a run without loss of the upper dynamics. As the compression control is advanced and compression is applied to the signal the overall level of volume is compensated for, if this were not done then adding compression would have the effect of reducing the volume of the sound as the available dynamics are reduced. The compression within the GP12SMX has been added as a means of creatively modifying your bass sound and as such becomes part and parcel of the overall sound character that you create, and not merely as an effect. It is for this reason that no compression bypass switching facilities have been included within the unit. Also by turning either compression control to its fully anticlockwise position removes all compression from the sound without significantly altering the overall volume.

High compression
The HIGH frequency compressor acts upon the high pass signal within the SOUND MANAGEMENT section. The HIGH COMPRESSION should be used with care as it is directly affecting the attack portion of the bass sound, this can be used to good effect but moderation should always be exercised when applying the high compression. As the compression control is advanced and the compression applied to the signal the overall level of volume is compensated for, if this were not done then adding compression would have the effect of reducing the volume of the sound as the available dynamics are reduced. However in the case of the HIGH compression circuit this means that when no signal is present then additional gain is added at high frequencies. The more the compression control is advanced the more additional gain. This in itself presents no problem as the electronics within the GP12SMX produce very little noise. However if you are using an active bass you may well find that adding high compression adds significant levels of HISS to the sound, this HISS is coming from the active electronics within your bass, this can be proven by unplugging the instrument from the GP12SMX input socket, and the hiss goes away.

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Using a passive bass with the GP12SMX will produce none of these problems unless excessive top boost is applied on the graphic. The two compression circuits can be set individually to produce some useful sounds, i.e. with LOW set to to about half to tighten up the bottom end of the sound, the HIGH can be varied in conjunction with the EQ BALANCE control to produce a variety of different attacks to the note to suit many different styles of playing.

Effects 2 level control
The EFFECTS 2 LEVEL control sets the level of the signals coming into the STEREO returns from the effects loop 2. This control has no effect unless the effects loop 2 is being used. EFFECTS LOOP 2 is covered comprehensively in the EFFECTS LOOPS section of these operating instructions.

Standby/On switch
The STANDBY/ON switch is to put the unit into STANDBY when either it is not being used or while changing guitars. It is also very important to switch to STANDBY when either turning the unit ON or OFF with the rear panel power switch. This will ensure that the valve has time to warm up and that the unit powers up and down silently.

Output level
The OUTPUT LEVEL control is used to set the stage volume of the amplifier, this will normally end up being set at between 3 and 4 on the scale with a TRACE ELLIOT output stage or power amplifier. This leaves plenty of available rotation of the output control in hand for when the unit is used to run non standard power amps that require a higher level signal input to drive them. However if you are using a TRACE ELLIOT output stage or power amplifier then please note that beyond about 4 on this scale your amplifier will almost certainly be running into clipping.

BACK PANEL FACILITIES
OFF POWER ON VOLTAGE SELECTOR V A.C. 230
DATE OF MANUFACTURE
250 1K

EARTH LIFT

MODEL:GP12SMX
SERIAL NO.

FULL RANGE LINE OUTPUTS
LEFT RIGHT

CROSSOVER LINE OUTPUTS
LOW PASS LEFT - HIGH PASS - RIGHT

BALANCED D.I.OUTPUTS MAINS FUSE LEFT - POST EQ - RIGHT
D.I. GND LIFT

FREQ PRE - E.Q.
LEFT

EFFECTS LOOP 2
- RETURN RIGHT MONO

STEREO
SEND

EFFECTS LOOP 1
+4 -10 RETURN

MONO
SEND TUNER OUTPUT FOOT SWITCH

1 3

2

1 3

2

1 3

2

-10

+4

MAINS INPUT

PIN 1 - GND

PIN 2 - SIGNAL+

PIN 3 - SIGNAL-

PARALLEL - HIGH PASS

SEND LEVEL

SERIAL - FULL RANGE

Footswitch socket
This is for connecting the external TRACE ELLIOT footswitch used for remote switching of the GRAPHIC and PRE SHAPE sections of the GP12SMX.

Tuner output
This is a line out socket with signal at a suitable level for direct connection to the tuner. Connecting a tuner in this way means you do not have to plug your tuner in line with your instrument and risk any degradation of the bass signal.The tuner may be left permanently connected without affecting the signal in any way. The signal at this output is taken from after the pre shape and may be used as an additional full range effects send if required.

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EFFECTS LOOP 1
+4 RETURN

MONO
SEND

Effects loop 1 mono

EFFECTS LOOP 1 is a full range, serial, mono effects loop i.e. the signal is the full range bass signal taken from after the graphic equalisation but prior to the -10 compression and the EQ BALANCE control. The signal level for this effects loop is switchable between -10dB and +4dB with the rear panel push switch to accommodate a wide range of effects units. As a general rule effects units intended to have the instrument plugged straight into them will use SERIAL - FULL RANGE the -10dB setting, as will most semi pro devices. The +4dB setting being a much higher signal level will overload the input to such devices and is there mainly for professional studio effects processors. This effect loop is the best position to use such devices as octave dividers or dynamic level control units as it is working with full range bass signal. Because this is a serial effects loop, the signal path through the GP12SMX is broken to include whatever effects unit is being used within the loop. Consequently the integrity of the bass signal will depend upon the quality of the direct signal through the external effects device being used.
EFFECTS LOOP 2
LEFT - RETURN RIGHT MONO

STEREO
SEND

Effects loop 2 stereo

EFFECTS LOOP 2 is a high pass, parallel, stereo effects loop i.e. the signal is the HIGH PASS signal prior to the EQ BALANCE control but after the HIGH COMPRESSION. This allows a small degree of compression to be added to the effects send signal keeping down peaks and allowing the effects unit to be SEND LEVEL driven harder without its input overload on the sharp peaks. The signal level for this effects loop is continuously variable between -10dB and +4dB with the rotary SEND LEVEL control, this allows you to optimise the level to suit any type of effects unit. Generally it is best to drive effects units as hard as you can without overloading the input this keeps the output noise from the unit to a maximum. Being a stereo effects loop there are two RETURN sockets marked LEFT and RIGHT. The right socket doubles as a MONO return if a jack is plugged into this socket alone delivering signal to both channels of the preamp stereo outputs. As this loop is a parallel type then you need only return the effect signal and not the direct DRY signal from the effects unit. This means the DRY signal is not degraded by the path through the effects unit itself. The level of the stereo return signals is adjustable with the front panel EFFECTS 2 LEVEL control and this is used to mix in the amount of effects required i.e. set the SEND LEVEL control to suit the input to the effects unit, leave this set at its optimum level and use only the EFFECTS 2 LEVEL front panel control to vary the return signal to produce the desired effect. If you wish to use this effects loop as a serial loop, this can be done by turning the EQ BALANCE control fully anticlockwise and then using the EFFECTS 2 LEVEL control to vary both the dry and effect signals together. The balance of dry to effect signal will then have to be set up in the external unit. Although this effects loop is dedicated HIGH PASS only it is possible to use it full range by taking the effects send signal from the EFFECTS LOOP 1 send socket.
-10 +4 PARALLEL - HIGH PASS

LEFT - POST EQ - RIGHT

PRE - E.Q.

Balanced D.I. outputs

Three balanced D.I. outputs have been provided on standard male XLR sockets, these are all available simultaneously. PRE EQ takes its signal from before the graphic equaliser but after the pre shape and POST EQ LEFT and RIGHT take their signal from after all equalisation, compression and effects loops but prior to the output level control. All three D.I.'s are of a fixed level to suit the LOW IMPEDANCE MICROPHONE input on a mixing console, a ground lift switch has been provided for these sockets to prevent ground loops occurring with interconnected equipment, this can only be used for balanced connections.
1 2 1 2 1 2 3 3 3 PIN 1 - GND PIN 2 - SIGNAL+ PIN 3 - SIGNAL-

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FULL RANGE LINE OUTPUTS
LEFT RIGHT

Full range line outputs
The FULL RANGE stereo output signal is available at the LEFT and RIGHT FULL RANGE LINE OUTPUT sockets. These are used for connection to a stereo power amplifier full range operation with the level of signal adjustable from the front panel OUTPUT LEVEL control.

CROSSOVER LINE OUTPUTS
LOW PASS LEFT - HIGH PASS - RIGHT

Crossover line outputs
The GP12SMX has a built in variable, stereo crossover with individual outputs for the stereo HIGH PASS LEFT and HIGH PASS RIGHT signals, and a mono output for the LOW PASS signal. The LOW PASS output has been made MONO as all the stereo directional information is contained within the higher frequencies and consequently is only present in the HIGH PASS signal.
CROSSOVER LINE OUTPUTS
LOW PASS LEFT - HIGH PASS - RIGHT

250

1K

FREQ

These outputs can be used to provide a STEREO BI AMPED system with the crossover frequency between HIGH PASS and LOW PASS variable between 250Hz and 1kHz with the FREQ control. For fully STEREO BI AMPED system you will require a two channel power amplifier to drive two high frequency cabinets for the stereo high pass signals and at least another single power amplifier of twice the power rating of the individual high pass amplifier. We would recommend that for the LOW PASS end you use another two channel power amplifier and drive two suitable low pass cabinets making a two dual channel amplifier and four cabinet setup. Remember when putting your system together that most of the power you will be using is in the LOW PASS end of the crossover. This is why we recommend that you use twice the power for driving the low frequencies and even better use two cabinets as well.

250

1K

FREQ

RA600 SWITCHED TO MONO

RA300

2103H

2103H

1153

1153

The EARTH LIFT SWITCH is provided to allow removal of the mains earth connection from the signal circuits of the GP12SMX to eliminate ground loops between connected equipment. The GP12SMX as with all TRACE ELLIOT equipment still maintains an earth connection to the chassis and all metal parts of the unit for safety even when the EARTH LIFT switch is used. NEVER lift the earth or ground to any equipment by removing the earth connection in the mains plug, this can be a potentially dangerous practice and in some instances prove lethal to both the equipment and the user.
VOLTAGE SELECTOR V A.C. 230

EARTH LIFT

Earth lift switch

Voltage selector
The VOLTAGE SELECTOR should be set to the appropriate voltage for your country prior to connection to the MAINS SUPPLY. When transferring from one country to another that uses a different voltage system you should also take note of the different MAINS FUSE required for that country. This is printed on the rear of the unit adjacent to the fuse holder.

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Power switch
Once the correct supply voltage has been set the GP12SMX can be turned on with the POWER switch on the rear of the unit. Always make sure the front panel STANDBY switch is in the STANDBY position prior to switching ON or OFF. This will ensure the GP12SMX powers up and down silently.

Mains fuse
In the event of having to replace the MAINS FUSE always use the same rating and type as marked on the unit's back panel. Using one of a higher rating will invalidate the guarantee. If after replacement the mains fuse should blow a second time, immediately refer the unit to a TRACE ELLIOT approved service engineer for checking.

GP12SMX technical specifications Inputs
Passive Bass Active Bass Effects return 1 Effects return 2
Input Impedance 2 Meg Ohms. Signal range 50mv to 10v (peak to peak) Input Impedance 100k Ohms. Signal range 100mv to 20v (peak to peak) Impedance 50k Ohms. Signal level switchable between +4 and -10dBv Impedance 50k Ohms. Signal level variable between +4 and -10dBv

Outputs
Effects send 1 Effects send 2 Line out (L&R) High Pass (L&R) Low Pass (mono) D.I. (Pre EQ) D.I. (Post EQ) Tuner Crossover
Impedance 10k Ohms. Nominal level switchable to +4 or -10dBv Impedance 10k Ohms. Nominal level variable between +4 and -10dBv Impedance 4k7 Ohms. Signal level - Nominal 0dBv. Max +8dBv Impedance 1k Ohms. Signal level - Nominal 0dBv. Max +8dBv Impedance 1k Ohms. Signal level - Nominal 0dBv. Max +8dBv Impedance 600 Ohms Balanced. Nominal level 600mv (peak to peak) Impedance 600 Ohms Balanced. Nominal level 600mv (peak to peak) Impedance 10k Ohms. Signal level 0dBv Variable between 250Hz and 1kHz

Supply Requirements 230/115v switch selectable at 20VA

14

AH300SMX REAR PANEL FACILITIES
N.B This section also applies to the rear panel facilities of the 1210HSMX, 122HSMX and 1215SMX models

Effects loop
The EFFECTS LOOP is a switchable full range/high pass, parallel, effects loop. When switched to FULL RANGE the signal is the full range bass signal taken from after the HIGH graphic equalisation but prior to the compression and EQ BALANCE control. When PASS switched to HIGH PASS the signal is the HIGH PASS signal prior to the EQ -10 +4 BALANCE control but after the HIGH COMPRESSION. This allows a small degree of compression to be added to the effects send signal keeping down peaks and allowing the effects unit to be driven harder without its input overloading on sharp peaks. The signal level for this effects loop is continuously variable between -10dB and +4dB with the rotary SEND LEVEL control, this allows you to optimise the level to suit any type of effects unit. Generally it is best to drive effects units as hard as you can without overloading the input this keeps the output noise from the unit to a minimum. As this loop is a parallel type then you need only return the effect signal and not the direct DRY signal from the effects unit. This means the DRY signal is not degraded by the path through the effects unit itself. The level of the stereo return signals is adjustable with the front panel EFFECTS 2 LEVEL control and this is used to mix in the amount of effects required i.e. set the SEND LEVEL control to suit the input to the input to the effects unit, leave this set at its optimum level and use only the EFFECTS 2 LEVEL front panel control to vary the return signal to produce the desired effect. If you wish to use this effects loop as a serial loop, this can be done by turning the EQ BALANCE control fully anticlockwise and then using the EFFECTS 2 LEVEL control to vary both the dry and effects signals together. The balance of dry to effects signals together. The balance of dry to effect signal will then have to be set up in the external unit.
SEND LEVEL
FULL RANGE

SEND

POST E.Q. D.I.

D.I. output
This D.I. output is a dedicated POST EQ output only and takes its signal from after all equalisation, compression and the effects loop prior to the output level control. This output is at a fixed level to suit the LOW IMPEDANCE MICROPHONE input on a mixer.

PIN 1 - GND PIN 2 - SIGNAL+

Tuner output
This is a line out jack socket with signal at a suitable level for direct connection to a tuner. Connecting a tuner in this way means you do not have to plug your tuner in line with your instrument and risk any degradation of the bass signal. The tuner may be left permanently connected without affecting the signal in any way. The signal at this output is taken from after the pre shape and may be used as an additional full range effects send if required.
FOOT SWITCH

Footswitch socket
This is for connecting the external TRACE ELLIOT footswitch used for remote switching of the GRAPHIC and PRE SHAPE sections of the GP12SMX.

Speaker Outputs
The two speaker output jack sockets are intended for connection to either a single 8 Ohm cabinet plugged into one socket, two 8 Ohm cabinets with one plugged into each socket or a single 4 Ohm cabinet plugged into one socket only. With combo amplifiers using the SMX300 output stage only one extension cabinet of 8 Ohms may be connected to the spare socket.

Cooling Vents
Never obstruct the free flow of air to the air vents on the rear of the unit by for instance hanging clothes etc. over the top of the amplifier as this can cause the output stage to overheat and may cause permanent damage to your amplifier.

15

AH400SMX REAR PANEL FACILITIES
The AH400 rear panel facilities are the same as those described within the GP12SMX instructions with the exception of the CROSSOVER section which is not included within this amplifier.

Full range stereo line outputs
The preamp in the AH400 is a stereo unit with the single 400 watt power output stage being driven from the RIGHT preamp output. A pair of STEREO LINE OUTPUT sockets are provided to allow the AH350 to be used as a full stereo unit with the addition of another power amplifier if required.

AH600SMX REAR PANEL FACILITIES
The AH600 rear panel facilities are the same as those described within the GP12SMX instructions with the exception of the CROSSOVER section. The AH600 CROSSOVER section has additional switching facilities to allow FULL RANGE STEREO or MONO BI AMP operation using the internal power stages. With the addition of an external two channel power amplifier STEREO BI AMP MODE may be used. The three different modes of operation will be dealt with in the following instructions with the aid of the diagram below of the CROSSOVER section.
LEFT
LINE OUT LEVEL LINE OUT

RIGHT
LEVEL FULL RANGE STEREO BI-AMP CROSSOVER FREQUENCY LEFT HIGH PASS LINE OUTPUTS RIGHT

1
0 LOW PASS LOW PASS 10 0 HIGH PASS LOW PASS 10

2
250 Hz MONO STEREO EXT. AMP 1KHz

Full range stereo
Both push switches in their OUT position selects FULL RANGE STEREO operation with the stereo signal from the preamp driving the LEFT and RIGHT power output stages. The LEFT LEVEL and RIGHT LEVEL controls adjust the output to each speaker enclosure driven from the two internal power stages. For FULL RANGE STEREO operation we recommend that you set these both to maximum and use the front panel OUTPUT LEVEL control to adjust the overall stage volume. If additional power is required you may use the LEFT and RIGHT LINE OUT sockets to drive an external power amplifier. The signal from these sockets is not affected by the setting of the LEVEL controls adjacent to them (these only adjust the internal power levels), this allows you to balance the volume from the internal power stages against the volume from the external power amplifier (using the external amplifiers own level controls) and once set the overall stage volume can be turned up or down using the front panel OUTPUT LEVEL control without disturbing this balance.

Bi-amp mono
Push switch 1 IN and push switch 2 OUT provides BI-AMP MONO operations with the LEFT power output stage now becoming LOW PASS and the RIGHT power output becoming HIGH PASS, as indicated by the arrowed graphics from push switch 2 through to the two level controls. Before using BI-AMP MONO mode made make sure that you have your low frequency speaker enclosure connected to the LEFT output and your high frequency unit connected to the RIGHT, as putting low frequencies through a high frequency only unit could destroy it.

16

PROFESSIONAL POWER AMPLIFIER (PPA) RANGE PPA300

CHANNEL - A
CLIP -6dB -15dB POWER CLIP -6dB

CHANNEL - B

PROFESSIONAL POWER AMPLIFIER

-15dB POWER

LEVEL

PPA300

LEVEL

The PPA300 is a rack mounting 150 watts per channel stereo (dual channel) power amplifier. It is 2 U in height and uses passive heat sinking for its output stages. This is a simple power amplifier to use having jack sockets for LINE INPUT and LINE OUTPUT with the speaker outputs being available on both JACK and XLR.

Power switch and mains inlet socket
The PPA300 is internally wired for the voltage marked on the rear panel adjacent to the mains inlet socket, check that this is correct for the supply with which it is to be used prior to connecting the mains cord to the unit. Once correctly connected the PPA300 may be turned on with the POWER switch. To indicate that the unit is in its powered up condition the LED's at the bottom of the front panel bargraphs will light.

Mains fuse
In the event of having to replace the MAINS FUSE always use the same type and rating as marked on the units back panel. If the fuse should blow a second time then immediately refer the unit to a TRACE ELLIOT approved service engineer for checking.

Ground lift switch
A GROUND LIFT switch is fitted to the PPA300 to prevent a GROUND LOOP being formed when multiple units are connected together (causing hum through the speakers). Use this to LIFT the ground from all but one of the interconnected units, the other units will still be grounded via the connecting signal cables so check these carefully. We provide GROUND LIFT switches on most of our equipment for the above reasons and also to make it unnecessary to remove the earth or ground connection from the mains plug (a common but potentially extremely dangerous practice). The GROUND LIFT switch on TRACE ELLIOT units disconnect the ground from the internal signal circuits only while still maintaining a permanent ground connection to all metal parts of the amplifier chassis and casing. In this way the casing of the unit can never become LIVE under any circumstances. This is one reason why you should never remove the earth from the mains plug.

Speaker outputs `A' and `B'
Each channel of the PPA300 is provided with an XLR and a JACK socket for speaker connection. It is recommended that the XLR socket be used whenever possible as this has higher current carrying capacity than the JACK socket. Each channel can deliver up to 150 watts into a speaker of 4 Ohms and slightly less into an 8 Ohm impedance. A simple bargraph display is provided to indicate signal through the power amplifier with the top LED indicating clipping of the output signal.

17

Speaker output fuses
Each channel has its own separate output fuse, this is a 5 amp fast blow type of fuse and should only ever be replaced with one of exactly the same type. In the event of having to replace this fuse, first check your speaker cables for short circuits ( the most likely and common cause of fuse failure) before using the amplifier again. Should this fuse blow a second time, immediately refer the unit to a TRACE ELLIOT approved service engineer for checking. Include your speaker cable so this may also be checked.

Line input and line output sockets
The LINE INPUT jack sockets are used for connection of signals into channels `A' and `B' of the PPA300. If a jack plug is inserted into one of these sockets only, then the signal will automatically be fed to both channels `A' and `B'. If jack plugs are inserted into both sockets then the channels will operate independently of each other. With either connection the level of both channel `A' and `B' is adjusted independently using the front panel `A' and `B' level controls. The LINE OUTPUT socket are connected in parallel with the LINE INPUT sockets and are for connection to further power amplifiers.

Using the PPA300 with a TRACE ELLIOT rack preamp
For a FULL RANGE system using a GP7SM preamplifier connect the LINE OUT from the GP7SM to channel `A' LINE INPUT on the PPA300, this will then drive both channels of the PPA300. Turn both channel `A' and `B' controls up full and use the OUTPUT LEVEL control on the GP7SM to set the playing volume. For a FULL RANGE STEREO system using a GP12SMX preamplifier connect the FULL RANGE RIGHT line output from the GP12SMX to channel `A' of the PPA300 and the FULL RANGE LEFT to channel 'B'. Turn both channel `A' and `B' controls up full and use the OUTPUT LEVEL control on the GP7SM to set the playing volume. For a BI-AMP MONO system using a GP12SMX connect the HIGH PASS RIGHT crossover line output to channel `A' of the PPA300 and the LOW PASS crossover line output to channel `B'. Make sure your high pass speaker is connected to channel `A' of the PPA300 and the low pass speaker to channel `B'. Turn up channel `B'. Turn up channel `B' control fully and use channel `A' control to adjust the amount of TOP END. Use the OUTPUT LEVEL control on the GP12SMX to set the playing volume. For this set up use the effects in MONO otherwise half of your effects signal (the half going to the LEFT RETURN socket) will not be reproduced. For BI-AMP STEREO it is necessary to have two dual channel power amplifiers, one to reproduce the stereo top end (high pass) of the signal and the other to reproduce the bottom end (low pass) signal with both halves of the second power amplifier running in MONO to give sufficient bass in proportion to the top end.

PPA600
The PPA600 is a rack mounting 300 watts per channel stereo (dual channel) power amplifier. It is 2 U in height and uses intelligent D.C. fan cooling for its output stages. This is a fully professional power amplifier having balanced signal LINE INPUTS on both XLR and JACK sockets. Balanced LINE OUTPUTS are also provided on both XLR and JACK for the easy interconnection of further power amplifiers. Speaker outputs are provided on JACK, XLR and SPEAKON connectors and a switch on delay is built in to prevent any power up thump from occurring.

Power switch and mains inlet socket
The PPA600 is internally wired for the voltage marked on the rear panel adjacent to the mains inlet socket, check that this is correct for the supply with which it is to be used prior to connecting the mains cord to the unit.

18

SPEAKER OUTPUTS MINIMUM LOAD 2 OHMS
SPEAKER FUSE T10A

CHANNEL - B
LINE OUT LINE IN LINE OUT LINE IN

'A' MAINS FUSE T4A 'B' MAINS FUSE T4A

EARTH LIFT LINE OUT

CHANNEL - A
LINE IN LINE OUT LINE IN

SPEAKER OUTPUTS MINIMUM LOAD 2 OHMS
SPEAKER FUSE T10A

WARNING

WARNING
TO REDUCE THE RISK OF FIRE OR ELECTRICAL SHOCK DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE. DO NOT OPEN - NO USER SERVICABLE PARTS INSIDE - DANGER OF ELECTRICAL SHOCK REFER TO QUALIFIED ENGINEER FOR SERVICE.

MODEL:-

PPA1200
SERIAL NUMBER

THIS APPARATUS MUST BE EARTHED. FOR CONTINUED PROTECTION AGAINST RISK OF FIRE REPLACE ONLY WITH SAME TYPE AND RATING OF FUSE.

PROFESSIONAL P.A.POWER AMPLIFICATION

V A.C.

MAINS INPUT

50/60Hz - 2000 WATTS

MADE IN ENGLAND BY:- TRACE ELLIOT TIMITED

Rear PPA 300/600/1200 diagram Once correctly connected the PPA600 may have either of its channels turned on with the POWER switches on the front panel. To indicate that the channel is in its powered up condition the LED at the bottom of the front panel bargraph for that channel to light.

Mains fuse
Both channel `A' and channel `B' of the PPA600 are individually fused as they are in fact entirely separate amplifiers with their own separate power supplies. In the event of having to replace a MAINS FUSE always use the same type and rating as marked on the units back panel.If the fuse should blow a second time then immediately refer the unit to a TRACE ELLIOT approved service engineer for checking.

Ground lift switch
A GROUND LIFT switch is fitted to the PPA600 to prevent a GROUND LOOP being formed when multiple units are connected together (causing hum through the speakers). This simultaneously lifts the ground from both internal power amplifiers. Use this to LIFT the ground from all but one of the interconnected units, the other units will still be grounded via the connecting signal cables so check these carefully. We provide GROUND LIFT switches on most of our equipment for the above reasons and also to make it unnecessary to remove the earth or ground connection from the mains plug (a common but potentially extremely dangerous practice). The GROUND LIFT switch on TRACE ELLIOT units disconnect the ground from the internal signal circuits only while still maintaining a permanent ground connection to all metal parts of the amplifier chassis and casing. In this way the casing of the unit can never become LIVE under any circumstances. This is one reason why you should never remove the earth from the mains plug.

Speaker outputs `A' and `B'
Each channel of the PPA600 is provided with an XLR a JACK and a SPEAKON socket for speaker connection. It is recommended that the SPEAKON socket be used whenever possible as this has higher current carrying capacity than the XLR or JACK socket. If the SPEAKON cannot be used the XLR socket only for the main output power cable, the JACK is only there for ancillary connection of an additional horn or high frequency unit. Each channel can deliver up to 300 watts into a speaker of 4 Ohms and slightly less into an 8 Ohm impedance. A simple bargraph display is provided to indicate signal through the power amplifier with the top LED indicating clipping of the output signal regardless of the impedance of the load.

Speaker output fuses
Each channel has its own separate output fuse, this is a 5 amp fast blow type of fuse and should only ever be replaced with one of exactly the same type. In the event of having to replace this fuse, first check your speaker cables for short circuits ( the most likely and common cause of fuse failure) before using the amplifier again. Should this fuse blow a second time, immediately refer the unit to a TRACE ELLIOT approved service engineer for checking. Include your speaker cable so this may also be checked.

19

Line input and line output sockets
The balanced LINE INPUT XLR and JACK sockets are used for connection of signals into channels `A' and `B' of the PPA600. Both channels operate entirely independently and will have to be linked with an XLR or stereo jack cable for mono use. Channels `A' and `B' are adjusted independently using the front panel `A' and `B' level controls. The balanced LINE OUTPUT sockets are connected in parallel with the LINE INPUT socket and are for easy connection to further power amplifiers. As stated above both the XLR and the JACK inputs are BALANCED inputs, however the amplifier may still be used with an unbalanced connection merely by inserting a mono jack plug into the jack input socket. This automatically switches the input to an unbalanced connection suitable for use with a GP12SMX or GP7SM preamplifier. If the power amplifier is being used with a balanced input into the XLR sockets then do not use a mono jack cable for linking or this will short out half of the balanced input connection. It is however quite acceptable to use a stereo jack cable for linking if required.

Using the PPA600 with a TRACE ELLIOT rack preamp
For a FULL RANGE system using a GP7SM preamplifier connect the LINE OUT from the GP7SM to channel `A' LINE IN on the PPA600 with a jack to jack cable, link the channel `A' LINE OUT to channel `B' LINE IN with another jack to jack cable , this will then drive both channels of the PPA600. Turn both channel `A' and `B' controls up full and use the OUTPUT LEVEL control on the GP7SM to set the playing volume. For a FULL RANGE STEREO system using a GP12SMX preamplifier connect the FULL RANGE RIGHT line output from the GP12SMX to channel `A' of the PPA600 and the FULL RANGE LEFT to channel `B'. Turn both channel `A' and `B' controls up full and use the OUTPUT LEVEL control on the GP7SM to set the playing volume. For a BI-AMP MONO system using a GP12SMX connect the HIGH PASS RIGHT crossover line output to channel `A' of the PPA600 and the LOW PASS crossover line output to channel `B'. Make sure your high pass speaker is connected to channel `A' of the PPA600 and the low pass speaker to channel `B'. Turn up channel `B' control fully and use channel `A' control to adjust the amount of TOP END. Use the OUTPUT LEVEL control on the GP12SMX to set the playing volume. For this set up use the effects in MONO otherwise half of your effects signal (the half going to the LEFT RETURN socket) will not be reproduced. For BI-AMP STEREO it is necessary to have two dual channel power amplifiers, one to reproduce the stereo top end (high pass) of the signal and the other to reproduce the bottom end (low pass) signal with both halves of the second power amplifier running in MONO to give sufficient bass in proportion to the top end.

PPA1200

CHANNEL - A OFF ON
CLIP -6dB -15dB POWER CLIP -6dB

CHANNEL - B OFF ON

PROFESSIONAL POWER AMPLIFIER

-15dB POWER

POWER

LEVEL

PPA1200

LEVEL

POWER

Front PPA 1200/600 Diagram The PPA1200 is a rack mounting 600 watts per channel stereo (dual channel) power amplifier. It is 2 U in height and uses intelligent D.C. fan cooling for its output stages. This is a fully professional power amplifier having balanced signal LINE INPUTS on both XLR and JACK sockets. Balanced LINE OUTPUTS are also provided on both XLR and JACK for the easy interconnection of further power amplifiers. Speaker outputs are provided on JACK, XLR and SPEAKON connector and a switch on delay is built in to prevent any power up thump from occurring.

20

Power switch and mains inlet socket
The PPA1200 is internally wired for the voltage marked on the rear panel adjacent to the mains inlet socket, check that this is correct for the supply with which it is to be used prior to connecting the mains cord to the unit. Once correctly connected the PPA1200 may have either of its channels turned on with the POWER switches on the front panel. To indicate that the channel is in its powered up condition the LED at the bottom of the front panel bargraph for that channel to light.

Mains fuse
Both channel `A' and channel `B' of the PPA600 are individually fused as they are in fact entirely separate amplifiers with their own separate power supplies. In the event of having to replace a MAINS FUSE always use the same type and rating as marked on the units back panel.If the fuse should blow a second time then immediately refer the unit to a TRACE ELLIOT approved service engineer for checking.

Ground lift switch
A GROUND LIFT switch is fitted to the PPA1200 to prevent a GROUND LOOP being formed when multiple units are connected together (causing hum through the speakers). This simultaneously lifts the ground from both internal power amplifiers. Use this to LIFT the ground from all but one of the interconnected units, the other units will still be grounded via the connecting signal cables so check these carefully. We provide GROUND LIFT switches on all of our equipment for the above reasons and also to make it unnecessary to remove the earth or ground connection from the mains plug (a common but potentially extremely dangerous practice). The GROUND LIFT switch on TRACE ELLIOT units disconnect the ground from the internal signal circuits only while still maintaining a permanent ground connection to all metal parts of the amplifier chassis and casing. In this way the casing of the unit can never become LIVE under any circumstances. This is one reason why you should never remove the earth from the mains plug.

Speaker outputs `A' and `B'
Each channel of the PPA600 is provided with an XLR a JACK and a SPEAKON socket for speaker connection. It is recommended that the SPEAKON socket be used whenever possible as this has higher current carrying capacity than the XLR or JACK socket. If the SPEAKON cannot be used the XLR socket only for the main output power cable, the JACK is only there for ancillary connection of an additional horn or high frequency unit. Each channel can deliver up to 600 watts into a speaker of 2 Ohms and 450 watts into a 4 Ohm impedance. A simple bargraph display is provided to indicate signal through the power amplifier with the top LED indicating clipping of the output signal regardless of the impedance of the load.

Speaker output fuses
Each channel has its own separate output fuse, this is a 10 amp fast blow type of fuse and should only ever be replaced with one of exactly the same type. In the event of having to replace this fuse, first check your speaker cables for short circuits ( the most likely and common cause of fuse failure) before using the amplifier again. Should this fuse blow a second time, immediately refer the unit to a TRACE ELLIOT approved service engineer for checking. Include your speaker cable so this may also be checked.

Line input and line output sockets
The balanced LINE INPUT XLR and JACK sockets are used for connection of signals into channels `A' and `B' of the PPA1200. Both channels operate entirely independently and will have to be linked with an XLR or stereo jack cable for mono use. Channels `A' and `B' are adjusted independently using the front panel `A' and `B' level controls.

21

The balanced LINE OUTPUT sockets are connected in parallel with the LINE INPUT socket and are for easy connection to further power amplifiers. As stated above both the XLR and the JACK inputs are BALANCED inputs, however the amplifier may still be used with an unbalanced connection merely by inserting a mono jack plug into the jack input socket. This automatically switches the input to an unbalanced connection suitable for use with a GP12SMX or GP7SM preamplifier. If the power amplifier is being used with a balanced input into the XLR sockets then do not use a mono jack cable for linking or this will short out half of the balanced input connection. It is however quite acceptable to use a stereo jack cable for linking if required.

Using the PPA600 with a TRACE ELLIOT rack preamp
For a FULL RANGE system using a GP7SM preamplifier connect the LINE OUT from the GP7SM to channel `A' LINE IN on the PPA1200 with a jack to jack cable, link the channel `A' LINE OUT to channel `B' LINE IN with another jack to jack cable, this will then drive both channels of the PPA600. Turn both channel `A' and `B' controls up full and use the OUTPUT LEVEL control on the GP7SM to set the playing volume. For a FULL RANGE STEREO system using a GP12SMX preamplifier connect the FULL RANGE RIGHT line output from the GP12SMX to channel `A' of the PPA1200 and the FULL RANGE LEFT to channel `B'. Turn both channel `A' and `B' controls up full and use the OUTPUT LEVEL control on the GP7SM to set the playing volume. For a BI-AMP MONO system using a GP12SMX connect the HIGH PASS RIGHT crossover line output to channel `A' of the PPA1200 and the LOW PASS crossover line output to channel `B'. Make sure your high pass speaker is connected to channel `A' of the PPA1200 and the low pass speaker to channel `B'. Turn up channel `B' control fully and use channel `A' control to adjust the amount of TOP END. Use the OUTPUT LEVEL control on the GP12SMX to set the playing volume. For this set up use the effects in MONO otherwise half of your effects signal (the half going to the LEFT RETURN socket) will not be reproduced. For BI-AMP STEREO it is necessary to have two dual channel power amplifiers, one to reproduce the stereo top end (high pass) of the signal and the other to reproduce the bottom end (low pass) signal with both halves of the second power amplifier running in MONO to give sufficient bass in proportion to the top end.

22

PPA power amplifier technical specifications
PPA300 Output power per channel 150 watts RMS into 4 Ohms 300 watts peak Total harmonic distortion (THD) Less than 0.05% at rated power Frequency response 20Hz to 30kHz - 1dB Power bandwidth 10Hz to 40kHz at rated power Slew rate 50 volts/uS Damping factor Greater than 200 at 4 Ohms Greater than 200 at 4 Ohms Greater than 200 at 4 Ohms 50 volts/uS 50 volts/uS PPA600 PPA1200

300 watts RMS into 4 Ohms 600 watts peak

600 watts RMS into 2 Ohms 1200 watts peak

Less than 0.05% at rated power

Less than 0.05% at rated power

20Hz to 30kHz - 1dB

20Hz to 30kHz - 1dB

10Hz to 40kHz at rated power

10Hz to 40kHz at rated power

Input details (except PPA300) Balanced 600 Ohms on XLR and STEREO JACK both with link through facility for simple chaining of power amps. Sensitivity = 0bBv for full output Output connections JACK

SPEAKON 1+ & 1XLR & JACK

SPEAKON 1+ & 1XLR & JACK

23

Loudspeaker cabinets
Each cabinet has one of two connector panels depending on whether a high frequency horn unit is included or not:Horn loaded cabinets Non-horn loaded cabinets

HF horn attenuator

Each cabinet has its own characteristic sound and different combinations should be tried to arrive at your ideal system. Adding an extension cabinet to a combo amplifier will significantly improve its performance in terms of power output and tonal versatility. Recommended applications are shown below:Type 1048H Speaker configuration 4 x 10" + high frequency horn Sound character / Application Tight bass, punchy mid range. Extended HF response. Good for percussive playing styles. As above, but without extended HF response. Balanced, full range sound. Suitable for a broad range of bass styles. Good low end - suitable for hard rock sound. Extended low frequency characteristics, but still with plenty of punch. Particularly good for low end of a bi-amp set-up. Tight bass, punchy mids, extended HF range. As above without extended HF response. Tight bass, good mid range, extended HF response. Portable add-on cab, particularly suitable as combo extension cab or as mid / high end of bi-amp system. Compact, portable extension cab particularly suitable as add-on for combos. Balanced all round sound. Add on extended high frequency only. As above, but with slightly more upper mids.

1048 1518

4 x 10" 1 x 15"

1524 1818

2 x 15" 1 x 18"

1048H 1084 2103H

8 x 10" + HF horn 8 x 10" 2 x 10" + HF horn

1153

1 x 15"

HF horn box 4052H

1 x high frequency horn 4 x 5"

24

Generally, a bigger cabinet will acheive better low frequency performance but careful attention to porting has brought better performance to all TRACE ELLIOT's bass speaker enclosures.

Where possible use XLR leads, as they provide a more reliable connection and less signal loss than jack to jack leads. Most TRACE ELLIOT cabinets have an 8 ohms impedance (the exceptions are the 1524, 1084H and 1084 models which have an impedance of 4 ohms). This means you can connect two cabinets to each output channel of a TRACE ELLIOT amplifier (In the case of the 4 ohm cabinets, only one can be connected per channel). Never connect two amplifier out put channels into one speaker connector panel.

Adding a high frequency horn unit or 4052H "Bright Box"
If you wish to improve the high end frequency response of your system, simply add one of either of these models and connect one of the jack sockets on your full range cabinet. You can ignore the impedance of the HF horn or the 4052H, which means you can use them in addition to two cabinets already connected to the output stage of any TRACE ELLIOT bass amplifier. You can also add one of these units to a combo amplifier by connecting it to the combo extension speaker output (N.B. except the 715, BLX80 and BLX150 models which have no extension speaker facility).

Speaker enclosure tuning
All TRACE ELLIOT speaker enclosures have the facility of variable tuning, allowing any system to be uniquely tailored by the user to their particular preference or to better suit a particular venue. A short description follows outlining the thinking behind this