Roland Eric Johnson Blues Cube Tone Capsule

The Roland Blues Cube amplifiers ship with a sweet vintage tube tone right out of the box. Eric’s custom Blues Cube tone, however, is available in a new and exciting product: the Eric Johnson Tone Capsule. The Tone Capsule is a modification circuit unit that changes the tube circuit characteristic of the original Blues Cube and attaches under the amp chassis.

The Tone Capsule looks like a guitar amp tube, but is actually a capsule that modifies the sound of your Blues Cube, to give it a even more valve-like tone. This is another innovative and revolutionary concept by Roland.

Once connected, the circuit modification on the Tone Capsule changes the tuning of the amp giving you custom tones and responses. The Tube Logic design physically amplifies the analog discrete circuit with characteristics produced by DSP circuits. Blues Cube’s basic sound quality is built upon the physical preamp and power amp. The analog discrete circuit and DSP circuit working together produce a very advanced path to tone.

Carefully connecting an oscilloscope to Eric’s amps gave the team a clear view of the waveforms detecting properties such as amplitude, frequency, rise time, time interval, distortion, and other factors. Eric commented, “We’re checking out some of my old amps and trying to infuse that into the Blues Cube, and right out of the shoot it’s working pretty well. It’s surprising. I think the response is more tube-like than it is solid state.” Bill and the Blues Cube engineers further discussed the guitar response. Bill wanted to know how Blues Cube was able to react like Eric’s amps. The engineer explained, “The Blues Cube creates real power sag in each circuit and component by dropping voltage of the power supply and intermodulation of power supply frequency, condition of the screen grid voltage and pre tube voltage.” This was a deep exchange of knowledge concerning Blues Cube modification.

Bill and the engineers made significant changes to the Tone Capsule with Eric personally testing each stage of the tone development. Using vintage Strats Eric spent days listening, playing, and dialing in his custom tones with Bill and the Blues Cube engineers soldering connections and turning knobs. Picking attack was carefully set, input capacitors were analyzed, and power supply sag specially produced to provide that wonderful bounce, dynamic and elastic bloom of a highly complex vintage amp—an amp inspired by Eric Johnson.

There are two channels on the Blues Cube: CLEAN and CRUNCH. Eric was able to dial beautiful clean settings inspired from his vintage Deluxe Reverbs. With just enough headroom, the pure clean tones of Blues Cube are reminiscent of many timeless Blues and Jazz songs. Pushed hard, the CLEAN channel breaks up with smooth dynamics. Eric commented, “I was very elated to find that the clean tone, if you turn it up, actually has a nice dirty rhythm tone too.” For CRUNCH, Eric’s classic 100 watt ’69 Super Lead inspired amazing lead tones with spectacular harmonics for Blues, Rock, and other styles. On one of Eric’s Super Lead Plexis, the input to the phase inverter has two capacitors with a one meg master volume potentiometer positioned between them—some of the many important details that were carefully considered in the signal path for this channel.

The TONE and REVERB settings are specially designed to give that warmth and expressiveness that is widely recognized in Eric’s sound. On both channels you’ll notice many of those brilliant EQ characteristics found in his tone. Eric continues, “I like the reverb in the Blues Cube. It’s really pure and pleasant sounding and I especially like it considering that some of my favorite reverbs are the old spring reverbs from the ’60s. The Blues Cube reverb is quite analog sounding. If it’s a reverb that just enhances the sound and doesn’t make me aware of it, just enhances it acoustically, then I think it’s a really good thing and that’s what the Blues Cube reverb does.”

Whether you are running effects through the front or in the effects loop, Blues Cube brings those sounds to life. Eric explains, “This amplifier is taking effects really well. If I run my Tube Driver or Fuzz Face through it, or any particular effects, it seems to be very flattering, which I think is important.”

Eric reflected on the audio sessions as they came to a close, “I’m a bit shocked at the solid state nature of the Blues Cube. This is probably the best solid state guitar sound I’ve heard.” The sky is the limit; it seems to me the potential is excellent.” The outcome of this incredible journey is, in Eric’s words, “only the beginning.” He continues, “The way people have been getting tone hasn’t really changed that much over the years. With Blues Cube, now there’s a way to produce tone with a much different method producing incredible possibilities. I’m excited to explore those paths.”