Sean Mandrake HB125 User manual

AudioStorm HotBox 125
The HotBox is a power attenuator, also sometimes called a power-soak or power-brake,
which absorbs a large proportion of the output power from your amplifier and converts it
into heat instead of volume. This allows you to capture the real overloaded vintage tones
of your heroes running their amps at eleven, but without deafening yourself.
Power levels
Your HotBox is rated for 125watts (HB125). This rating is the loudest amplifier you should
use with your HotBox. As long as your amplifier is well serviced then you can turn it up
to 11 and drive it as hard as you like, for as long as you like: The HotBox is built exactly
for this purpose. You can also always use a lower powered amplifier without issue.
Decibels, watts and human hearing
Human hearing is non-linear. This means that halving the watts does not half the volume.
Percentage markings on the HB125 are not actual reduction amounts but are instead
estimations of what each reduction ‘sounds like’ to a typical human ear.
How to use your HotBox
The HB125 offers four reduction levels plus bypass.
The switches work in series, each one feeding into to the next.
When all switches are up (off) the unit is in bypass mode. In bypass mode you MUST
have a speaker connected to the HotBox or else your amp will not be connected to
anything and damage may occur.
Switching only the first (30%) switch on (down) will engage the first step of reduction and
your speaker will receive 30% of the amplifiers output power..
If the next (10%) switch is also turned on (down) then this will reduce your output to 10%.

Connections
To use your HotBox simply connect it in-line with the speaker output of your amplifier.
Your amp or head goes to the ‘AMP’ socket on the box and then take another speaker
lead from the ‘SPEAKER’ socket to your speaker cabinet. In the case of combos this is
usually the built in lead. You may use either or both of the speaker out jacks on the
HotBox at the same time. They are wired in parallel thus connecting two 16 ohm cabs
will give the same impedance as connecting one 8 ohm cab alone.
Amplifier
Engaging the next switch will reduce your output to 3%
And the final switch will reduce your output to 1%
Other combinations of switching can be used to directly swap between two different
reduction levels without having to traverse the in-between reduction. For example,
switching the large 30% switch in the following instance will move from bypass to 3%.
Inductive / Resistive mode
Resistive mode (up) uses British-made, wirewound aluminium
clad power-resistors to give a tighter, more modern sound.
Inductive mode (down) uses a huge, British-made custom wound
power inductor to give a looser, more vintage sound.
You can change modes at any time you choose and they work for all reduction settings.
Speaker Cabinet
Amplifier
Speakers
HotBox
Speaker Cabinet

http://www.seanmandrake.com
All AudioStorm pedals are and designed and hand built by SeanMandrake. As such, every pedal
will vary slightly and cosmetic imperfections are to be expected and are considered normal.
Sometimes our parts suppliers change their prices or stock. Although AudioStorm will do everything
in their power to keep a product the same sometimes we are forced to make changes and thus we
reserve the right to substitute different parts or make these changes as needed.
Every pedal is built from carefully selected components. If your HotBox malfunctions AudioStorm
will repair or replace it (at our discretion) for at least twelve months from the purchase date.
This guarantee excludes damage caused from unreasonable abuse. This includes but is not limited
to: liquid damage of any sort, high impact physical damage, cosmetic damage, failure to follow
instructions in this manual and damage from using an incorrectly specified PSU. This guarantee
also assumes that any equipment this unit is connected to is in good condition and thoroughly
serviced. We take no responsibility for damage to equipment this unit is connected to, especially
when exacerbated by neglect or failure to properly and thoroughly maintain equipment.
Terms, conditions and warranty
I accidentally connected the leads the wrong way around!
The HotBox can handle this and it won’t hurt your amplifier. However the HotBox will NOT be
working correctly and this is not recommended.
Does the impedance (16 ohm, 8 ohm, 4 ohm) really matter?
It depends on the amp manufacturers quality. Some amps can tolerate mismatch where some
it will cause damage. Read their guidelines.
I measured my speaker impedance and it’s 7.3 ohm / 13.5 ohm etc.
Speaker impedance is only a very rough measurement. Use common sense so 7.3 is ‘8’ and
both 13.5 or 17.1 are ‘16’ (or 15 on vintage amps).
Will it sound ‘exactly’ like an overloaded amp
No. But it will be very close. You are not driving the speaker as hard so you might prefer to use
a lower powered speaker, perhaps 5 to 10w, to improve your tone.
It doesn’t sound ten times quieter. It’s faulty!
Human hearing is not linear. Ten times in power is only about four times in perceived volume.
Bedroom levels are often only a tiny fraction of a watt.
Where does it go in my signal chain again?
If you have a head it goes between the speaker cab and the amplifier head. In the case of a
combo you will have to disconnect the speakers according to the manufacturers instructions
and insert it there. A very small number of amplifiers have a hard-wired speaker and you may
have to contact a technician to replace this with a speaker jack socket in this case.
Does the HotBox need batteries or a power supply?
No.
Why is the HotBox so much cheaper than the competition?
Our product uses clever manufacturing techniques and cutting edge components.
Can I use the HotBox as a dummy load?
We do not recommend this but it is safe to do so if you use 1% reduction level mode.
Will the HotBox get hot?
Yes. How hot depends upon your amp and how much cool air surrounds the box. If the HotBox
gets super-hot your amp valves or bias may be faulty and we strongly recommend you get
your amp tested by a competent technician because it may be putting out too much power.
FAQ