Ideally we’d all have sufficient time, space, money and equipment to plug whatever guitar we liked into whatever amp we fancied, turn it up to 11, then have an expert recording engineer place the perfect microphone in the perfect place to capture THE TONE, before amplifying it with a discrete Class A mic pre and capturing the resulting signal on a finely maintained tape recorder. Or something like that!
In the real world where time is short, neighbours have kids who apparently need to sleep at night, recording engineers want to be paid and the singer wants to use the mic, we’ll generally take whatever help we can get. This is why we have devices like the Red Box.
The Red Box 5 is the latest (I’m guessing that it’s the 5th) in a series of red boxes produced by H&K since the late 1980s. And what is it? It’s a DI box. That’s Red.
I’ve talked about DIs before in Making Tracks (in GI 22, to be precise). You could use the Red Box at various points in the signal chain such as on a pre-amp or FX line-out, but the input impedance is probably too low to use it as an instrument DI and let’s be honest, it’s really designed to plug into the signal path between the amp output and the speaker. Do not assume that all DI boxes are; if you use one that isn’t you could destroy your DI box and your amp and suffer the other consequences of too much electricity where it doesn’t belong! The box has IN and THRU sockets that you connect to the amp and speaker respectively (using speaker leads, not instrument cables) and an XLR socket for the balanced mic level signal (standard mic cable). If your pre-amp or desk has phantom power then use that to power the box, otherwise you can use a battery or an external PSU that plugs-into a small power socket by the XLR output.
When you take your signal from after the power stage of your amp, you capture the contribution of your power tubes and transformers (if you have them of course). Listen to that signal and chances are that you’ll think it sounds - awful. Guitar speakers are thankfully very poor at converting the signals fed to them into sound, their natural filtering cuts off the harsh top end of the signal, and the various bumps and dips in their frequency and time responses gives their individual character to the sound we hear. Add to that the effect of the cabinet construction and what we’re used to hearing is a long way from what comes out of that “SPEAKER 1” socket. So what’s the point? Well, you can record that amp signal then use a software cab simulator (I often do this) or you can use a hardware cab simulator - and that’s exactly what the Red Box gives you - a DI box with build-in cab emulation.
Pros and cons? Well, you don’t get the flexibility of the software-sim approach, but you do get to treat the speaker simulation as part of your rig and record a finished track that you don’t have to mess about with before you start the mix. What the Red Box doesn’t do is provide a load for the amp - you MUST have a suitable speaker attached (which means that it’s going to get as loud with the box as without it) or use a power attenuator or load box to replace the speaker if you want silence. I used the Red Box like this and it’s slightly frightening to be standing next to a completely maxed-out Marshall head full of glowing glass, with guitar tones gently trickling out of the studio monitors!
Why not use a mic? Convenience - consistent results in seconds, no careful mic placement needed, no bleed onto your guitar tracks, it’s unobtrusive and not sensitive to being knocked - and it does give you the silent option with a load box. Obviously, for live use it’s also a great way to get a signal to the desk without worrying about the singer kicking your mic over when landing from a mid-air splits.
On the top surface of the box is a row of switches that set options for attenuation and ground lift, along with loose/tight, vintage/modern and small/large. Some of the differences are fairly subtle and seem to overlap a bit, but a few minutes playing with them makes a useful difference to the sound and adds flexibility to the box. I will mention that these switches are circuit board mounted and felt a little insubstantial - though they all worked perfectly and are in a recessed slot to protect them.
How does it sound? Possibly not quite like you’d initially expect it to. The box is designed to emulate the sound of the speakers, not the speakers heard through a recording chain (so no mic emulation) and it’s really difficult to compare a monitored DI signal to live 12” speakers that are bouncing sound off everything in the room. I didn’t personally think that the box sounded like any of my own cabs, but once I got past that I actually found the sounds to be both well-judged and useful. Suffice to say that after I recorded some test tracks for a song writing project I’m working on, when I came back to the rough mix a couple of days later I didn’t even notice until I checked my track notes that I was listening to DI tracks.
Would I recommend it? If the convenience appeals to you, then yes, absolutely. There are more sophisticated options available but the Red Box sounds very good, it’s probably as close to an industry standard as you’ll find, and it costs less than just about any mic that you’d commonly use on a guitar cab!
Wish list – Red Box with a dummy load in the box please!