Guitar: Going Direct


When my buddies flew in to track I didn’t want to leave anything to chance. I like my Fender Twin’s sound but I also wanted to have a good direct sound. I run Samplitude 11 Pro and this version has a very nice amp simulator called Vandal. I’ve heard people rave about Vandal. Some calling it the best simulator out there. I’m not ready to make that claim… yet. We’ll see how these guitar oriented recordings turn out.

Anyway, I wanted to capture a good direct sound. I’ve never had the need to run dual amps or split my guitar signal so I started where I always start: Reading the boards, certain reviews, talking to musician friends.

Turns out I was a bit late on the draw. The local stock was thinner then I expected and some of my choices weren’t available. What was available and on my list was the Radial Pro DI passive direct box, and the Whirlwind Selector switch.

These are different devices.

The Radial is a DI box but also has a “thru” output. The “thru” will go to my amp. The proper output will go to my RME Fireface 800’s instrument input.

The Whirlwind selector is designed solely to split signals. Again, one to the amp one to the Fireface 800’s instrument input.


The first time I used a DI box was a long time ago. And over the years I’ve never fully understood what they actually did.  I still don’t but here is a stab.

DI’s convert an unbalanced low level signal to a balanced line level signal. They take a low voltage, convert it to a higher one, and keep the resistance the same. They are pre amps that minimize noise, allow you to use longer cable runs, and plug into line level inputs.

I don’t care about any of that. I care about the sound. Will they suck tone? Will they add noise? Will they sound better then my Really Nice Preamp or the instrument input on my RME Fireface 800?

The short answer on these particular devices? Yes, they do suck tone. Yes, they do create noise. I can get better tone running into my Fireface instrument input or my Really Nice Preamp. But DO NOT take my word on it. Just listen to the tests. Make up your own mind.

Here are the signal paths. I’ve taken care to use the same cables, try and duplicate guitar performances, and have the guitar in the same position for noise considerations. Since louder things actually sound different (Fletcher-Munson curves)  I’ve normalized everything. But rest assured they were all recorded at about the same level.  Your basic scientific-ish method trying to isolate the variable we are interested in.

  1. Really Nice Preamp. This was the fullest and most natural sounding to my ears. Transients seemed less harsh/cheap [audio:
  2. Instrument input on RME Fireface 800. Runner up with less fullness and harsher transients. Might be useful for a cleaner sound. [audio: DI.mp3]
  3. (Signal split) Whirlwind Selector -> Instrument input on RME Fireface 800/Fender Twin amp. Forth place. Watered down direct tone and sure adds noise to the amp.
    [audio: Selector Fireface DI.mp3][audio: Selector Amp.mp3]
  4. (Signal split) Radial Pro DI passive direct box -> (DI output) Instrument input on RME Fireface 800/ (thru output) Fender Twin amp. Third place. A more natural tone, but too watered down for my liking, way less noise then the Whirlwind when using the pin-1 lift button. Yes there is more noise in the direct signal. To be fair this passive DI is designed to take a higher level input. I used a lot more gain (noise) on the Fireface to record at comparable levels.[audio: Pro DI Fireface DI.mp3][audio: Pro thru Amp.mp3]

I included the split into an amp so I could compare how much noise would be added and if there was a difference in tone.  Before the signal hit my Fender Twin it hit a  Keeley mod Tube Screamer. This made any added noise ever louder.

What I hope to find is a solution to split my signal without loss of tone and added noise. If that isn’t available I’ll look into re-amping. My goal is to get a decent direct signal into my amp and DAW.

Perhaps these devices aren’t meant to deliver studio quality sound. They may be better suited to stage where the listener will be none the wiser. But if you’re planning to record consider what a splitter or DI could add or take away from your tone.

2 thoughts on “Guitar: Going Direct

  1. Rich

    DI’s do not (traditionally) bring the signal up to line level. They convert the high impedance signal of your instrument to a low impedance one that is seen as microphone level. The RME is acting as your preamp in your case. Actually the RME has a DI built in when you use the instrument input. DI’s also can help by isolating ground loops, very handy in the live sound world.

    So your conclusion about the DI sucking tone is a bit lacking in logic. If you have and instrument that is high impedance (ie guitar) then if plug it directly into a mic preamp(without a built in DI) it will not sound as good as one with one. However certain guitar tones such as a Nirvana song were recorded this way specifically for the trebly out of phase sound.


  2. cporro Post author

    now i know why i changed majors out of electrical engineering.

    where does ohm’s law fit into all this? i was reading that impedance is resistance for AC. sounds a bit more complicated then DC because you have to account for phase. that would make guitar signals… AC?

    I’m not saying DI’s suck tone. I’m saying these 2 devices sucked tone. one is an active splitter the other a passive DI. neither is what i’d consider a typical DI. this is a very gear specific comparison not a general statement. and i suppose tone is subjective. some might love the washed out and definition-less tone. most won’t. that’s why i posted the audio. choose for yourself.

    going back to ohms law I = V/Z (and my failed attempt at electrical engineering). going from high Z (impedance) to low Z would require a drop in voltage or current. So you may be right, and i wrong, about input levels. but i really don’t like to step down from my god podium and later i might send locusts. watch out.

    i don’t get what you are saying about the nirvana stuff. you aren’t saying he was out of phase right? because i can’t figure out how that would happen. you need 2 signals for phase issues. you’re just saying he liked that tone?



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