Introduction to the HotBox

Valve amps sound their best turned up to eleven but most of us live in a world where neighbours, police, the guys in recording studios and our bleeding eardrums just can't put up with all that volume. That's where the HotBox comes in, it sucks up most of the power your amp puts out and allows you to work it really hard so get that sound, but without the pain.

AudioStorm are experts in Power Attenuator design.

We've been making and selling these units for many years and have countless satisfied customers. Don't settle for some el-cheapo unit with air cooled resistors or a terrible rheostat when you can have our cutting edge technology instead.

Models

The HotBox is available in a variety of different models

  • The HotBox 60 Studio is a rugged, entry level unit for the player who feels their amp is just that bit too loud.
  • The HotBox 60 Pro adds switchable reduction to choose between jamming at home and studio recording levels.
  • The HotBox 120 offers switchable reduction and higher power handling to suit amplifiers up to 120watts.
  • The HotBox 125 is our flagship with four carefully chosen levels of reduction and a switchable inductor.
  • The BurnBox is a pure analogue, Inductive Direct Recording Speaker Simulator that works with any HotBox.
HB60S HB60P HB120 HB125

What watts are what?

Human hearing is really advanced, difficult to understand and doesn't always make sense. For this reason we design our units so that they just work and so that you don't need to be a rocket scientist to understand how to get the tone you want.

In order to help you select the right HotBox we've put together a (hopefully) straightforward chart:

  • YELLOW : 5 watts and above is too loud for practicing at home but ideal for studio, pub and creative jams.
  • GREEN : 2-4 watts is usually ideal for daytime jamming at home.
  • BLUE : 1 watt and below is ideal for quiet jamming but you may sacrifice a little tone.
HotBox Reduction
sounds like...
Decibels Ratio 120watts becomes... 60 watts becomes... 30 watts becomes...
60 Studio One-third -10dB 10:1 n/a 6w 3w
60 Pro (High) One-third -10dB 10:1 n/a 6w 3w
60 Pro (Low) One-eighth
-15dB 30:1 n/a 2w 1w
120 (High) One-quarter
-11dB 12:1 10w 5w 2w
120 (Low) One-tenth
-18dB 60:1 2w 1w 0.5w

 

HotBox 125

The HotBox 125 covers all the ranges above, offerring -8, -11, -15 and -19dB reduction levels in addition to inductive reduction to soften the high end. The 125 is suitable for all amplifiers from 1 watt to 125 watts.

More info please?

No problem!

Why is 100w only slightly louder than 50w?

In order to hear a wide range of volumes, from super-quiet to super loud, and everything in-between, our hearing works in a non-linear way. Our amazing biological ear-technology means that even though halving the power does halve the volume we only hear aroud a 10% difference! That's why a 100 watt amp only sounds slightly louder that a 50 watt. Try not to get hung up on watts and instead think logarithmically, so: 10 watts is double 1 watt, and 100 watts is double 10 watts.

Are all 50w amps equal?

Simple answer: No, nowhere near equal. For one thing, watts are not a measure of volume: They are a measure of power consumed whilst trying to make volume, which is why some amps are louder than other amps of the same power-rating. Some amps are just more effeicient at turning watts into volume than others (Yes, we're looking at you Plexi!!).

Do speakers make a difference?

Speakers also vary in how efficiently they can change watts into volume: a speaker of 100dB/1w (which means 100 decibels of volume for 1 watt of power) such as the Celestion Vintage 30 is twice as loud as a Hi-Fi speaker with 94dB/1w. Every 6dB is a doubling in real world volume! A 50watt amp with 100dB/1w speakers is -exactly- the same volume as a 100w amp with 97dB/1w speakers.

Resistive vs Inductive

Both types of attenuators have advantages and disadvantages. Resistive attenuators generally offer a tighter, more focussed sound and inductive ones a looser, more organic sound. Both types sound equally fantastic, just subtly different.

Inductors are very expensive to wind and incredibly complex to design well so are only found in premium attenuators. The HB 125 is switchable between resistive and inductive and all our other models are resistive only.

Why no variable control?

Rotary controls are generally unreliable. It's that simple:

High-power rotary variable resistors, often called L-Pads are designed for high-frequency tweeter use in non-overload conditions. You can make them work in a power attenuator but they'll get super-hot, sound bad whilst they are hot and eventually burn out. This is why we don't use them. They are also really cheap and easy to implement. This is why some of our competitors use them.

Rotary switches are almost all designed for low-current use. Speaker signals are the opposite: high-current. You can use rotary switches in a power attenuator but they'll almost certainly get hot, the contacts will 'arc' and eventually, over time, they'll burn out. Again, they are really cheap to buy plus they look good, so are very popular with manufacturers.

Toggle switches are designed for very high current use but good ones are expensive. They'll last forever, never get hot, never sound bad and never burn out. This is why we use them.

My head hurts now...

That's why we've done all the hard work for you: So you don't have to. Just pop back up to the table above to choose the attenuator that suits you and trust us. We know what we're doing :)