If you’ve read our reviews of the Quilter SuperBlock US and Yamaha’s THR10II desktop amp, you know that we’re finding a lot to like in today’s crop of digital modeling and solid-state amplifiers. And of course, Fender’s Tonemaster series has been highly acclaimed, with many players stating that they feel the tones from the Tone Master Deluxe Reverb and Tone Master Princeton Reverb are nearly indistinguishable from their tube counterparts. In this article I’m going to discuss an obvious but useful tone tweak for warming up your digital amp with tubes.
The key word however, is “nearly” indistinguishable. This raises the question of how close is close enough? That of course, depends on your ears and your taste for tone.
The Magic of Tubes
When people talk about “tube magic”, they are talking about two aspects of tone: Sound and Feel. In terms of sound, tubes can often lend a sweetness and color to a guitar signal that is difficult to reproduce in any other way. Guitarists who ride the clean/dirty line tend to love the touch dynamics that a tube signal chain offers. Pick lightly and your tone is clean, dig in and you get distorted textures to the notes. Even with completely clean tones, tubes offer a dynamic response that feels “softer” than many digital amps. More on that later.
Best of Both Worlds
Without further delay, I’ll come right out and cut the suspense. The tweak we’re talking about is simply adding a tube distortion pedal into the signal chain of a solid-state or digital modeling amplifier. The pedal I’m using is the Mesa/Boogie V1 Bottle Rocket Tube Preamp. Although this pedal is no longer in production, used examples can be found on Reverb. Of course, there are numerous tube-based distortion pedals that you can use. The point is to get at least one vacuum tube into your signal chain. That Pedal Show on YouTube did a current roundup of tube distortion pedals available today:
Firing The Bottle Rocket
Now back to my particular tube experiment. I’ve owned the Mesa/Boogie Bottle Rocket for quite some time, and haven’t found a great use for it. The Bottle Rocket is often regarded as a little brother to the more famous Mesa/Boogie V-Twin. Although it has fewer features than the V-Twin, the Bottle Rocket delivers smooth Boogie tone. With the Bottle Rocket, you can get everything from warm cleans to full on saturated, liquid gain. Much of my playing is clean, so I have admittedly used the Bottle Rocket sparingly. However, I have a weakness for the Boogie sound and legendary build quality, so I’ve kept it handy for years.
If you’ve read our Quilter SuperBlock US review and 6-month follow-up review, you know that I’ve been very happy with the SuperBlock. It’s ideal for Fender-style cleans at low to moderate volumes. The Quilter’s Limiter knob works similar to a compressor. The intent of the Limiter is to replicate the feel of a real tube amp. Overall, it is very useful, and smooths out the attack in a pleasant way.
Despite my satisfaction with the Quilter’s tones, I found myself wondering if I could warm them up even more. I’m not saying that the Quilter’s sound is brittle by any means. The Quilter’s treble can be tamed by backing off of the treble control, increasing the Gain, and adjusting the Limiter control to taste. Since I had the Bottle Rocket sitting around, I decided to give it a try.
Bottle Rocket + SuperBlock = ?
To maximize the signal path, I used the cleanest, highest fidelity cable I own, the Evidence Audio Lyric HG. We reviewed this cable in our Guitar Cable Shootout, and the Lyric HG does not disappoint. This is a clear, smooth sounding cable that doesn’t color your tone. To ensure consistency, we also used an Evidence Audio Lyric HG patch cable to connect the pedal to the SuperBlock.
Before we talk tone, I have to disclose that the Bottle Rocket isn’t in completely in stock form. From the factory, the pedal comes with two 12AX7 tubes. Though it sounds excellent in this configuration, I have experimented with lowering the gain. One of the great things about tube pedals—and amps—is the ability to tailor the response to your desired gain level. In my case, I favor clean to lightly overdriven tones. Therefore, I swapped in a 12AU7 in the first tube position. The 12AU7 is a direct substitute for the 12AX7, but has a gain factor of 20, vs. 100 for the 12AX7. Essentially, I maintain the sound of the Bottle Rocket, but with lower gain.
SuperBlock + Bottle Rocket Sounds
Upon plugging in, the first thing I noticed is also the most prominent factor: Smoothness. Tubes are known for their thicker, more colorful response. When I introduced the Bottle Rocket in the signal path, the difference was immediately noticeable. The biggest change was in the the attack of the note, however. One of the things I don’t like to hear in my electric tone is a spiky, sharp sound a the “front” of the note. This is the transient that you hear first as a note is picked. Inserting tubes in the signal immediately softened the slight “spikiness” that I hear from the Quilter at times.
I know what you’re thinking: “Hey, I thought you said the Quilter sounded great?” It does! And the Limiter control definitely tames any brittleness. However, like any compressor-type control, it robs a tiny bit of the dynamics as well. This is where I feel that the Bottle Rocket really helped. With the Bottle Rocket in the signal chain, I can back off of the Limiter control and maintain superior dynamics as well as a smoothed-out attack.
Keep in mind that that these impressions are based on the mostly clean tones that I typically play with. With the Quilter set for my typical clean sound, I set the Bottle Rocket’s Gain control at around 10:00 and the Output knob at 12:00. I was able to get a warm, clean tone, with just the slightest amount of overdrive if I dig in with a pick. Of course, you’ll need to experiment with these settings based on your particular amp and pedal combination.
Conclusion
With all of the talk about today’s digital modeling making tubes unnecessary, perhaps we’re jumping the gun a little bit. While big, heavy tube amps may be an increasingly endangered species, enhancing your digital amp with tubes is simple and convenient.
The SuperBlock US definitely does not need a tube pedal to sound good. As well designed as the SuperBlock is however, I have to admit to enjoying the effect that tubes have in the signal path. Although the Bottle Rocket has True Bypass circuitry, I still hear a positive audible effect even when the pedal is switched off!
Warming up your digital amp with tubes is as simple as finding a suitable tube pedal. Many tube pedals can be found for very reasonable prices on the used market. Really then, there’s no reason not to experiment with this easy tone tweak. And while a tube pedal is great for warm cleans, another obvious benefit is that you’ll also be able to access real tube distortion. Happy Playing!