2. Safety precautions
Please read and check if you have understood all instructions in this manual.
Always take some basic safety precautions when using your
amp
two in order
to minimize the risk of injury through fire or electric shock.
Pay attention to all warnings, instructions and additional texts on the
amp
two.
Always use an earthed power supply with the correct mains voltage. If you
are in doubt about the power outlet’s ground, have it checked by a qualified
technician.
Use only fuses with the same current rating and trigger characteristic as repla-
cements. Never mend fuses! Should a fuse blow again after a short while, the
device needs to be checked.
Pay attention to an unhindered air circulation in the amplifier’s surroundings.
Never obstruct the air vents or grilles.
Do not install or use your
amp
two in close proximity to water or if you are
soaking wet yourself.
Use your
amp
two in a safe place where nobody can step on cables or trip over
and damage them.
Do not install your
amp
two close to devices with strong elec tromagnetic
fields such as large mains transformers, revolving machines, neon illuminati-
on etc. Do not lay signal cables parallel to power current cables.
Cable up your
amp
two only if it is powered off.
Always pull out the mains plug before you clean your
amp
two. Use a damp
cloth for cleaning. Avoid the use of detergents and do not let any liquids enter
into the unit.
There are no user-servicable components inside your
amp
two. All mainte-
nance, adjustment and repair works should be carried out by qualified staff
only. Any unauthorized tampering will void our 2-year warranty.
Keep this manual in a safe place!
3. Concept
It was our ambition to put a professional unit with tremendous power, great
features and outstanding tonal qualities into a small portable cabinet to make
the ‘whole bass’ really happy.
It’s been known for a long time how innovative today’s bass players are and
how they love trying out new things.
No doubt has the electric bass evolved into a ‘solo instrument’; for this reason
the acoustic and technical requirements have gone up steeply and conse-
quently the demands on the engineers as well.
Straight talk
A distortion-free, rock-solid and deep bass reproduction finds itself in cons-
tant opposition with physics, human perception and what product costing
still accepts as in line with market conformity.
A lot more energy is needed to give the fundamental bass notes the same vo-
lume as midrange or treble frequencies. The aim is a harmonic reproduction
of the instrument’s pure tone, irrespective of resonance and formant ranges.
In theory several problematic issues can add here in a negative way:
• The human ear is far more sensitive at middle frequencies than at any other
tonal ranges.
• The instrument shows a very uneven reproduction of its individual spectrum.
There are big differences in level, dispersion characteristic and sustain which
produce frequency cancellations and peaks.
• The reproduction of low bass frequencies requires more ‘energy’ and puts
a lot more stress on the material as well as the components – the more so if
extra amplification is made using equalization (e.g.: +15dB at 80 Hz equals the
5.6-fold voltage at this point or 31.6 times more power).
Tonally speaking, the ‘bass’ is a very demanding instrument. Its reproductive
capabilitiy extends over the entire audio spectrum. The level-relevant distri-
bution, however, is very disproportionate. In general the lows and particular-
ly the highs are greatly boosted to achieve a well-balanced signal which can
then be further processed by sophisticated tone controls.
The random interaction of pickups, pre and power amplifiers, each with nu-
merous controls and varying quality degrees, will soon reveal limitations that
will entail a mediocre signal-to-noise ratio of the whole audio chain and cut
down on dynamics, since the power amplifer, power supply or components
hit their performance limit too early.
By now it should be clear how complex the problem is and why we have taken
quite a different approach to realise our tonal ideas, letting the ‘bass’ sound
the way it wants to sound.
• An analogue 200 watts power amplifier with high dynamic reserves and a
massive power supply provides the required output power.
• The analogue signal processor monitors the signal so that the full output
power can be called on without an ample ‘headroom’ which would be requi-
red otherwise. This will spare you space and weight, save the loudspeaker
and provide constant, defined power amp conditions. Since this is a ‘closed
system’ (power amp, processor and loudspeaker), all components can be per-
fectly matched while ensuring maximum efficiency without overstraining the
system. We go to the limits, but not beyond.
• We have chosen a 10” Sica instrument speaker chassis. This loudspeaker is
highly suitable for a good bass response, especially in small ported cabinets.
However, response characteristic, power handling and efficiency are interde-
pendent factors so that dedicated bass chassis are always a bit lower in volu-
me (approx. -3dB) than all-purpose speakers. The chassis has been tested for
electrical and mechanical dependability according to AES standard.
• The cabinet must withstand an enormous strain. It is made from 18 mm slot
-
ted, waterproof laminated birch plywood. The speaker chassis sits in a separa-
te ported chamber to provide optimum uncoupling from the electronics.
• Additional features:
- Compressor
- Adjustable XLR DI out
- Line out, tuner out, headphones out
- Footswitchable >Mute< and >Effect on/off< functions
- Pre and post EQ inserts
- Effects loop
- Ground lift
- Adjustable AUX input
