Most guitar players will tell you that the best your tube amp will ever sound is when it’s absolutely cranked. And they’re right. Anyone who says any different does not enjoy good tone. #realtalk
Naturally, this means if your amp isn’t being pushed (i.e. is at a lower volume) it doesn’t sound quite as good. To get your tube amp anywhere close to a pushed state, or farther away from a low volume, means you’re unlikely to be able to play at a reasonable volume (for others that is, WE LIKE IT LOUD!). Tube amps are simply loud. 25w of tube power will destroy 50w of sold state power.
These days we have 20w Mesa Rectifiers, Orange Terrors, even 5w and 10w heads that sound killer. This is new though. 20 years ago if your all tube head wasn’t 100w or more (looking at you, 300w Crate Blue Voodoo), you weren’t using good gear!
But even in a lot of studio contexts, that’s still too loud. And most venues you play are going to be too small for a dimed amp. If not for the overall mix, for the excessive stage volume.
So what do people do to get a cranked sound at lower volumes?
They get a power attenuator.
What Does A Power Attenuator Do?
A Power Attenuator is essentially a high-tech post-preamp and power amp volume knob.
If you turned your amp on without it being connected to an appropriately rated speaker, you’d risk blowing it up. That electrical energy has to go somewhere, it can't just sit in the amp. This is normally rectified (no pun intended!) by connecting to a speaker cab. The speakers safely absorb the load from your amp.
So in order to effectively control this volume, a power attenuator has to do the same. Even though it’s eventually connecting to a speaker cab, the load has to be dealt with early on in the signal flow in order for the volume to do anything.
Sitting in between your amp and your speaker cabinet, the power attenuator takes your amp’s full signal and load, gives you a volume control, and then goes into your speaker cabinet.
You take your standard speaker output of your amp into the dedicated input on the power attenuator, then the speaker out on the power attenuator to your speaker cabinet.
You get the cranked up tone of your amp at a reasonable volume.
Power Attenuators vs Load Boxes
If you’ve researched power attenuators you more than likely have seen load boxes pop up. What are load boxes and what’s the difference between a load box and a power attenuator?
They're kind of the same thing, but also different.
A power attenuator can be thought of as a volume control. It sits between your amp and your speaker cabinet. It takes your cranked signal, safely handles the electrical load, and lets you turn the volume WAY down when you take it into your speaker cabinet.
Load boxes also take your amp’s electrical load, but unlike power attenuators aren’t meant to go into a speaker cabinet. They’re intended to go directly into a PA or recording interface, and typically have a speaker emulation. You can think of them as DI boxes that can safely take an amp’s load. It converts your amp’s signal into a line or mic level signal.
But, some power attenuators also have an emulated mic output or direct line out to go into a recording interface.
I know, confusing.
I personally think every single emulated speaker out on any hardware device is pretty worthless. If you’re really looking to take your amp directly into your interface, you should get Impulse Response software.
Several companies actually make small pedals that act similarly to power attenuators. The difference is they 1) don’t take any electrical load, and 2) goes into your amp’s effects loop. It’s actually quite clever. It’s a straight up volume knob.
JHS has the Little Black Box micro pedal that replaces power attenuators. Power attenuators can get really expensive, and this pedal retails for about $45. Instead of going in between your amp and cabinet, it sits in your effects loop. But instead of lush delays and reverb, you get a post-preamp volume knob.
Since your preamp is where most of your tone comes from, it may be worth the sacrifice of power tube saturation for pretty-close cranked tone at low volume. Especially for the low cost of a dinner for two.
If your amp doesn’t have an effects loop, you’re hosed.
How To Use A Power Attenuator
Before you purchase a power attenuator, make sure you know your amp’s wattage and the ohm rating of your speaker out. Your amp may have several speaker outs at different ohm ratings, and likewise you can find power attenuators that have multiple ohm inputs.
Besides the obvious importance of ohm ratings, you want to make sure your power attenuator is rated at twice the wattage of your amp. Anything less can cause the power attenuator to break. And smoke. And get really hot.
The obvious #1 application for a power attenuator is to use your rock stack at home. Apartment dwellers will be the first to benefit from this. Followed by musicians who don’t live by themselves, or live in a house that is very close to others.
What might not be so obvious is using them at gigs. Unless you’re playing stadiums, you probably can't get away with a cranked combo amp, let alone a 100w heavy metal machine! But you can get all the tone of your amp at a reasonable stage volume.
If you’re using in ears and want a quiet stage, you can leave your cab at home and use the emulated speaker out most power attenuators and load boxes have built in.
My favorite application though, is using power attenuators (or load boxes if your power attenuator doesn’t have a line out) to record. You’ll need IR software, but you can get some killer cabs from companies like OwnHammer for cheap. They have bundles of popular cabs for about $30, and individual cabs for less.
ML Sound Labs has a FREE cab sim with a slick interface. You only get one speaker/cab but it’s truly free with several mic and mic placement options.
This bypasses a physical cab altogether. And again, if you’re in an apartment this is vital.
One thing that I haven’t touched on is the contributions your speakers give to your tone when they’re pushed, as opposed to when they’re not. Just like pushing your preamp and power amp gives you luscious tone, pushing your speakers also provides something unreplaceable to your tone.
While you can effectively push your speakers at a gig while using a power attenuator, you can’t reasonably do that in your bedroom. I’m not quite sold on virtual amps yet. I just haven’t found any that have the same life as one with physical circuitry.
BUT, I have heard a lot of IRs that get pretty close to the life a physical cab provides. Close enough at least.
Do You Need A Power Attenuator For Solid State Amps?
No. Since solid state amps don’t use tubes, the tone you get when your volume is at 3 is the same as your tone when your volume is at 10 (or more appropriately, 11).
But if you’re in an apartment and you want to use your amp with an IR, you can get a load box to interface with your interface. If you have both solid state and tube amps, then a power attenuator with a non-speaker line out can be a versatile tool for you.
What Are The Best Power Attenuators For Guitar Amps?
Surprisingly, there aren’t as many options for power attenuators as you might think. This could be due to the rise of lower wattage amps (no more 300w tube heads), amps with built in wattage settings, and amp sims coming pretty close to emulating real amps.
But, there are some wonderful options anyway. These more than make up for the fact that there aren’t 50 different options to choose from. Of the dozen or so common and respected attenuators and load boxes, these three stand out from the crowd.
Two Notes Torpedo Reload Reactive-Active Attenuator
The Torpedo by Two Notes is a power attenuator load box and reamping tool in one. It even comes with the Wall Of Sound III speaker cab emulation. If you already have a cab or are using this with an impulse response, it has you covered there too.
The tone is top notch no matter the amount of attenuation, or what output you use.
Universal Audio OX Load Box
The Universal Audio OX Load Box is another top notch load box, as you’d expect from a company like UA. When paired with the app for Apple and PC devices you have the option to use their built in cabs, mics, and rooms- all with a stunning level of control.
The interface is really slick. If you don’t care about that, then you’ll enjoy a versatile load box with several outputs to match your specific uses. Including 4, 8, and 16 ohm operation.
Two Notes Torpedo Captor
If you don’t need all the bells and whistles, and simply need a load box that gives you the best audio, then the Torpedo Captor is your best bet. You can choose from 4, 8, or 16 ohm versions (you have to buy each separately). While not as expansive as the Torpedo Reload Reactive-Active Attenuator, you do get a built in cab sim which is perfect for small stages.
Check Your Power Rating
The general rule of thumb here is to get an attenuator that is rated at least twice the wattage of your amp. So if you’re using a 50w amp you’d want a 100w power attenuator.
There are cheaper options out there that what I’ve included here, but beware of the attenuators for under $200. They’re not all bad, but the quality isn’t quite as good. Both in audio and in the actual unit.
I’ve heard of cheap attenuators smoking when used for long durations. Who knows, it could have been someone using the wrong impedance.
But one thing I’ve learned over the years is cheap gear is cheap for a reason.
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