Ashdown 12-BAND 600 User manual

USER MANUAL

Thank you for purchasing your Ashdown Engineering Amplier and
welcome to the family! We really think you’ve made the right choice and
know that this amplier will give you years of great tone and service.
It is a machine though and needs to be looked after, please read
through this user manual which will help you get the most out of
your new Amp and keep it running as long as some of our
happiest and very famous customers.
Please register this product online so we can make sure we give you years
of customer support through our friendly in-house service centre.
Here is where you need to visit to register your product:
http://www.ashdownmusic.com/pages/register-your-product
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ASHDOWN ENGINEERING - 12-BAND 600 USER GUIDE
INTRODUCTION
After being asked by countless friends and Ashdown fans to re-introduce the
formidable 12-BAND head, previously the MK-500.
We proudly present the 12-BAND 600.
The 12-Band bass amplier uses a sought-after Ashdown pre-amp featuring a
12-band graphic equaliser for the most versatile tone shaping available and
Harmonic Emphasis to provide the ultimate in Hi-Fi for Bass. Coupled with
balanced XLR instrument input and a simplistic design approach, the signal
path is kept to an absolute minimum for maximum signal integrity and
pure tone.

FRONT PANEL FACILITIES
INSTRUMENT INPUT - There are two Instrument Inputs. The rst of these is a Jack
socket suitable for all Passive or Active bass instruments with a conventional jack
output. This will perfectly match the high impedance output from a passive bass but
also has sufcient headroom to accept the lower impedance and higher signal level
from active instruments. The second input is a balanced XLR input for the ultimate
in low impedance interconnection between bass instrument and amplier. This may
be used with both balanced or unbalanced connections but is best used with a true
balanced connection where it will give up to 100dB of common mode rejection,
cancelling any noise picked up on the instrument connection cable.
INPUT CONTROL - The INPUT control sets the signal level through the preamp
in conjunction with the INPUT LEVEL VU Meter. This is adjusted to give a reading
of 0VU on the meter for average playing dynamics with occasional peaks into
the red region. Please note that the setting of this may have to be re-adjusted
after modication of the EQ controls. It is most important to set this control to the
optimum (as described above) to get the best noise free performance.
HARMONIC EMPHASIS - HARMONIC EMPHASIS is a new addition within this
amplier and consists of a circuit that takes the bass signal and emphasises
harmonics within it to produce a bright zingy top end. It is not an EQ circuit, it
actually synthesises new harmonics, adding these to the original sound. The best
way to describe this is that it is similar to the top end zing you get from a new set of
strings.
ASHDOWN ENGINEERING - 12-BAND 600 USER GUIDE

This has a LEVEL control and can be switched in or out with the front panel switch.
Used in moderation, you will nd it adds a lot of bright, high harmonics to the sound
giving denition and clarity not achievable in any other way.
GRAPHIC EQUALISER - The GRAPHIC EQUALISER section operates by boosting
or cutting the level of signal at various frequency points throughout the frequency
range. With the sliders set on 0dB (in their centre ‘click’ position ) no alteration
is made to the signal. Moving any one of the sliders up will increase or ‘boost’
the signal at the frequency marked below the slider. Moving the slider down will
decrease or ‘cut’ the signal at that frequency.
The GRAPHIC EQUALISATION can be switched in or out with the front panel switch.
A carefully designed GRAPHIC EQUALISER is a very exible 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.
Because of the exibility and massive BOOST and CUT potential of this particular
GRAPHIC it is important to know how to get the best from it.
Firstly a few things not to do and the reasons why:
1. Do not boost or cut all frequency bands as this will have the same effect as
increasing or decreasing the overall volume level without affecting the tonal
characteristic of the sound.
2. Do not use excessive bottom (30 to 40Hz) boost on the graphic unless your
speakers can handle it. Very few speaker systems are capable of handling
ASHDOWN ENGINEERING - 12-BAND 600 USER GUIDE

ASHDOWN ENGINEERING - 12-BAND 600 USER GUIDE
frequencies as low as 30 and 40Hz with any degree of efciency. 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 ap 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.
3. Do not use excessive top (10 to 15kHz) boost, this will add mostly hiss to the
sound as there is very little signal output at this frequency from a bass.
The 30Hz slider has been provided to allow precise tailoring at very low frequencies.
This slider should be used to CUT (not Boost) the 30Hz to a level that allows the
speaker system to work at its maximum efciency.
USEFUL OBSERVATIONS
The fundamental frequency range of a regular, four string 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 and more.
The attack portion of the note also produces other high frequencies when the string
is rst struck. This attack can be emphasised by boosting the top end. However
because of the fairly small range of frequencies from a bass, by top end we mean
between 2.6kHz and 5kHz. You will nd that 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.

ASHDOWN ENGINEERING - 12-BAND 600 USER GUIDE
Above this frequency range you will nd it is better not to boost the signal as this
will mainly emphasise any hiss present. This hiss will not be masked by the bass
signal when playing due to the very small amount of bass guitar 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 ampliers to drive them. You will nd that rolling
off the bottom end by using these two sliders will allow you to play at a far greater
volume level without the speakers complaining.
Try to keep the graphic sliders balanced around 0dB and in a smooth owing curve
from one slider to the next, and remember that after adjusting the graphic you may
need to re-set the INPUT GAIN.
DI - The DI or DIRECT INJECT socket is a balanced, low impedance XLR output
intended for connection into the Microphone Input on one channel of a mixing
desk. This is to carry the signal to the P.A. system for larger gigs. It is balanced and
low impedance to ensure that no noise is added to the signal on the way to the
mixer. The level of this signal has been set to be similar to that from a microphone so
that it will work without overloading the input on a desk that has no input Pad switch.
The signal connections are as follows: Pin 1 = Ground, Pin 2 = Signal +, Pin 3 =
Signal -. The DI signal can be switched to be PRE or POST EQ. PRE EQ is before any
of the amplier’s facilities or EQ but after the INPUT GAIN control. POST EQ is after
all internal facilities and includes the external effects loop.

ASHDOWN ENGINEERING - 12-BAND 600 USER GUIDE
MUTE/TUNE - The front panel MUTE switch provides a mute facility that can be
used to silence all outputs from the amplier except that from the TUNER output
socket. This enables silent tuning to be carried out whilst the amplier speaker
outputs, the DI the Effects Send and the Line Output are all muted. Once in tune the
amplier can be un- muted and playing resumed. This switch can also be used as
a STANDBY switch for silencing the amplier during pauses in its use. A blue LED
below this switch will illuminate to indicate when the amplier is Muted.
To make use of the Tuning facility plug the output from the TUNER socket into the
INSTRUMENT input on your tuner.
OUTPUT LEVEL - The OUTPUT LEVEL control is used to set the stage volume of
the amplier. Use this control to adjust for increases or decreases in your playing
volume and not the INPUT GAIN control, this should always be left set to the
optimum for your instrument.
LINE OUTPUT - The LINE output is for connection to external power ampliers and
speakers to allow you to build a larger more powerful system. This output is situated
after the OUTPUT LEVEL control to allow the entire connected system to be turned
up and down with a single control.
If you require a line output that is not affected by the OUTPUT LEVEL control you
may use the EFFECTS SEND jack socket, this will obviously not include any effects
loop signal.

ASHDOWN ENGINEERING - 12-BAND 600 USER GUIDE
REAR PANEL FACILITIES
EFFECTS SEND/RETURN - A serial effects loop is provided at a level of 0dB.
The EFFECTS SEND socket can also be used as a Line Out socket if required as the
signal path through the preamp is only broken when a jack plug is inserted into the
EFFECTS RETURN socket.
The EFFECTS SEND is situated after the EQ.
SPEAKER OUTPUT - The Speaker Output sockets are also situated on the rear panel
of the unit and are provided on both Jack & Speakon connectors.
REAR PANEL FACILITIES:

SPECIFICATIONS:
Inputs
Jack Input Impedance - 3.9M Ohms Input range 150mv to 20v p - p
XLR Input Balanced - 600 Ohms Input range 100mv to 10v p - p
Effects Return Impedance - 10k Ohms Input level 0dbu nominal
Outputs
Tuner Output Impedance - 22k Ohms Level 0dbu nominal
Line Output Impedance - 1k Ohms Level 0dbu nominal
Effects Send Impedance - 22k Ohms Level 0dbu nominal
D.I.Output Impedence - 600 Ohm Balanced Level -20dBu Nominal
Equalisation
Graphic EQ +/- 15db @ 12 centre frequencies
Speaker Outputs Min Impedance -4 Ohms 500 Watts RMS 1000 Watts Peak
Frequency Response -3db at 17Hz and 30kHz
ASHDOWN ENGINEERING - 12-BAND 600 USER GUIDE

ASHDOWN ENGINEERING - 12-BAND 600 USER GUIDE
NOTES: